Kaushik Rabadiya

8 simple SEO tips for blogs

2008-12-06T11:59:00.000-08:00

Follow these simple rules for search engine optimization and your blog will rank much higher in Search Engines.

Use your primary keyword in your blog domain
The first thing to do is to ensure that your blogs URL contains the primary keyword you want to optimize for. Using the targeted keyword in subdomains also helps.
For example, if you want to start a HTML tutorial site then the primary keyword you want your URL to contain is html. So choose a URL like www.htmlhelp.com.
You can also use the keyword in subdomains like www.web-design.com/htmlhelp
Use your primary keyphrase in the title of your posts
If your primary key phrase is html help make sure that the word html and help appear in your blog headers such as H1 and H2 tags as well as the title of each of your posts.
Use your secondary keywords in the body of your post
If you want to get listed for secondary keywords use them infrequently in the body of your post. The theory is that the more times a keyword appears within a Webpage, the more relevant the page is likely to be for someone searching those keywords.
But do not overdo this by repeating the same keywords over and over again. Google bots can find out if a keyword is too frequent on a page and might just remove your site from their index.
Use your keywords in the anchor text of links
Use your primary and secondary keywords in the anchor text of links when linking to other blog posts or to other pages of your blog. Keyword in links have more importance than simple text.
Make sure search engines can spider your blog easily
Make sure your navigation bar is present on all pages of your blog. Your previous posts or atleast the popular ones should be linked to all pages so they get spidered easily.
Get backlinks from other blogs
You need as many links as possible to link back to your posts or blog because it will help you build pagerank and get your blog to rank higher in search engines. The more links you have the higher your blog is ranked in Technorati helping your blog to be found easily.
So how do you get backlinks?
- The first thing to do to get high-quality links is to submit your blog and RSS feed to blog search engines and directories.
  Start by submitting your blog to all the directories listed on this page:
  http://www.masternewmedia.org/rss/top55/
- Link exchanging with other similarly-themed blogs will help you to form richly interlinked networks or communities.
- If you find an interesting article on another blog, link to it generously. The trackback will become a link back to your blog.
- Lastly posting legitimate comments in response to posts on other blogs will help you get backlinks. Regularly post legitimate comments in similarly-themed blogs with high traffic to get many backlinks.
Update your blog frequently
Update your blog frequently using all the rules mentioned above and your blog will surely get top rankings in a short time.
Stick with your blog
Once you start posting on your blog, stick with the same domain or you could end up losing a lot of your traffic and regular readers.
Also stick with the topic you selected for your blog. If it’s about pets don’t suddenly switch to another topic such as Gadget’s because you will loose traffic.

For tips on building traffic to your blog, read the series- How to increase your blogs traffic

Instantiating components on template markup

2008-12-06T03:24:00.000-08:00

All client-side template engines enable you to create HTML (feel free to go ‘duh’). What they don’t all allow is the creation of event handlers and components over the markup they generate. The general approach with those engines is to do a second pass of code over the markup to create handlers and components. This is quite unfortunate as this generally requires some knowledge of the markup (which plays against separation of concerns) or something like the introduction of marker CSS classes into the markup.

For our own template engine, we wanted event handler creation and component instantiation to be first class scenarios, and we wanted both to be possible from imperative code as well as declarative code.

Imperative code blocks

Let’s start with the imperative approach. The template engine enables the introduction of code blocks right inside the template and also exposes a $element that is a reference to the last created element from the point in the template where it is referenced. So a first approach might be to just hook events and create components from there. Sure enough, that works:

<img sys:id="{{ $id('photo') }}"      sys:src="{{ 'Images/' + Photo }}"      alt="{binding FirstName}" />  <br /> <input type="text" id="{{ $id('firstName') }}"        class="editInPlace name"        value="{binding FirstName}" />

Please note that the comment-based code block syntax is on its way out and will be replaced in the next preview with an attribute-based alternative. I will give more details when that is available. Suffice it to say for now that this mixing of component instantiation code into markup is not what we intended code blocks for. Code blocks are there to make simple scenarios like conditional rendering and looping over markup as easy as possible.

Unobtrusive and imperative

The better imperative approach looks very much like how you would do things outside of a template if you’re into unobtrusive JavaScript. The way you add event handlers and components over the page’s markup is by subscribing to some page ready event (pageLoad or Sys.Application.add_init in Microsoft Ajax, $(document).ready in jQuery). From that handler, you query the DOM for specific elements and add event handlers and components on those.

To do the same over a template, you handle the itemCreated event of DataView, query the DOM that was just created for the data item and then add event handlers and components.

One problem with repeating markup is to create unique IDs for the generated elements. This is relevant to the problem at hand because referencing elements by ID is by far the most common way. Wouldn’t it be nice to be able to just use getElementByID? Well, in client templates, we provide you with an easy way to both generate unique IDs and to reference elements by ID.

Unique IDs can be generated by the $id function that is part of the execution environment of templates (along with $dataItem, $element, etc.). $id takes a string parameter, which is an ID that is unique within the template, and combines it with the current data item’s index to generate an ID that can be unique within the page:

<img sys:id="{{ $id('photo') }}" sys:src="{{ 'Images/' + Photo }}"      alt="{binding FirstName}" />

To reference those elements -even if you don’t know the pattern $id uses to globalize the id-, you can use the getElementById method that is provided by the template context, which is conveniently available from the event arguments of itemCreated:

args.get_templateContext().getElementById("photo")

Here’s what the code to add an event handler and a behavior looks like:

function onItemCreated(sender, args) {     var context = args.get_templateContext(),         dataItem = args.get_dataItem();     $addHandler(context.getElementById("photo"), "click", function() {         alert("You clicked " + dataItem.FirstName + "'s photo.");     });     $create(Bleroy.Sample.EditInPlace,            { cssClass: "editing" }, {}, {},            context.getElementById("firstName")); }

Note: there is a known bug in Preview 3 that prevents getElementByID from working correctly outside of IE. We fixed that bug already for the next preview.

Fully declarative

Of course, if you prefer a fully declarative approach, we allow that too. The template engine understands DOM-0 event handlers in pretty much the same way that the browser does outside templates (we tried to apply the principle of least surprise here). This means that if you specify for example an onclick attribute on an element, it is understood as a string that is the source code for the body of a function that will act as a handler for the click event. The template engine also supports binding expressions on attributes and this is no exception. That means that you can actually build that string expression that will become the body of the handler dynamically using the current data item:

<img sys:id="{{ $id('photo') }}" sys:src="{{ 'Images/' + Photo }}"   alt="{binding FirstName}"   onclick="{{'alert(\'You clicked '+FirstName+'\\\'s photo.\');'}}"/>

Important note: you should be super-careful about building such handler strings on the fly with embedded data: there is potential for injection here, if the FirstName data came from the user or an uncontrolled source. In a real application, you'd want to encode FirstName to escape any quotes. You may useSys.Serialization.JavaScriptSerializer.serialize(FirstName) for example.

Then, to instantiate the components, you can use our declarative syntax (which will also be the subject of a future post):

<input type="text" id="{{ $id('firstName') }}" class="editInPlace name"        value="{binding FirstName}"        sys:attach="inplace" inplace:cssclass="editing"/>

Conclusion

There are plenty of options to add event handlers and components over template-generated markup in Microsoft Ajax, catering to different coding styles, but we hope we succeeded in keeping the system as simple as possible while keeping all relevant scenarios possible.

Download the full code fro the demo here:
http://weblogs.asp.net/blogs/bleroy/Samples/EventsAndBehaviorsInTemplates.zip

ASP.NET MVC on IIS 6 Walkthrough

2008-12-06T03:19:00.000-08:00

I’ve seen a lot of reports where people have trouble getting ASP.NET MVC up and running on IIS 6. Sometimes the problem is a very minor misconfiguration, sometimes it’s a misunderstanding of how IIS 6 works.

In this post, I want to provide a definitive guide to getting ASP.NET MVC running on IIS 6. I will walk through using the .mvc or .aspx file extension for URLs first, then I will walkthrough using extension-less URLs.

If you’re running into problems with IIS 6 and ASP.NET MVC, I recommend trying to walk through all the steps in this post, even if you’re not interested in using the .mvc or .aspx mapping. Some of the lessons learned here have more to do with how ASP.NET itself works with IIS 6 than anything specific to ASP.NET MVC.

Initial Setup

To make this easy, start Visual Studio and create a new ASP.NET MVC Web Application Project on the machine with IIS 6. If your IIS 6 machine is on a different machine, you can skip this step. We can deploy the site to the machine later.

After you create the project, right click the project and select Properties. The project properties editor will open up. Select the Web tab and selectUse IIS Web Server. Click on the image for a full size view.

In the project URL, I gave it a virtual application name of Iis6DemoWeb and then checked Create Virtual Directory. A dialog box should appear and you should now have an IIS virtual application (note this is different than a virtual directory, as indicated by the gear looking icon) under your Default Web Site.

Using a URL File Extensions

When you run the ASP.NET MVC installer, it will set up an ISAPI mapping in IIS 6 to map the .mvc extension to the aspnet_isapi.dll. This is necessary in order for IIS to hand off requests using the .mvc file extension to ASP.NET.

If you’re planning to use extension-less URLs, you can skip this section, but it may be useful to read anyways as it has some information you’ll need to know when setting up extension-less URLs.

Mapping .mvc to ASP.NET

If you plan to use the .mvc URL extension, and are going to deploy to IIS 6 on a machine that does not have ASP.NET MVC installed, you’ll need to create this mapping by performing the following steps.

One nice benefit of using the .aspx extension instead of .mvc is that you don’t have to worry about mapping the .aspx extension. It should already be mapped assuming you have ASP.NET installed properly on the machine.

For the rest of you, start by right clicking on the Virtual Application node (IIS6DemoWeb in this case) and select Properties. You should see the following dialog.

Make sure you’re on the Virtual Directory tab and select Configuration. Note that you can also choose to make this change on the root website, in which case the tab you’re looking for is Home Directory not Virtual Directory.

This will bring up the Application Configuration dialog which displays a list of ISAPI mappings. Scroll down to see if .mvc is in the list.

In the screenshot, you can see that .mvc is in the list. If it is in the list on your machine, you can skip ahead to the next section. If it’s not in the list for you, let’s add it to the list. You’re going to need to know the path to the aspnet_isapi.dll first. On my machine, it is:

c:\windows\microsoft.net\framework\v2.0.50727\aspnet_isapi.dll

It might differ on your machine. One easy way to find out is to find the .aspx extension in the list and double click it to bring up the mapping dialog.

Now you can copy the path in the Executable text box to your clipboard. This is the path you’ll want to map .mvc to.

Click Cancel to go back to the Application Configuration dialog and then click Add which will bring up an empty Add/Edit Application Extension Mapping dialog.

Fill in the fields with the exact same values as you saw for .aspx, except the extension should be “.mvc” without the quotes. Click OK and you’re done with the mapping.

Specifying Routes with an Extension

Before we run the application, we need to update the default routes to look for the file extension we chose, whether it be .mvc or .aspx extension. Here is the RegisterRoutes method in my Global.asax.cs file using the .mvcextension. If you want to use the .aspx extension, just replace{controller}.mvc with {controller}.aspx.

public static void RegisterRoutes(RouteCollection routes) {   routes.IgnoreRoute("{resource}.axd/{*pathInfo}");    routes.MapRoute(     "Default",     "{controller}.mvc/{action}/{id}",     new { action = "Index", id = "" }   );    routes.MapRoute(     "Root",     "",     new { controller = "Home", action = "Index", id = "" }   ); }

Note that because the second route, “Default”, has a literal extension as part of the URL segment, it cannot match a request for the application root. That’s why I have a third route named “Root” which can match requests for the application root.

Now, I can hit CTRL+F5 (or browse my website) and I should see the following home page.

And about page.

Notice that the URLs contain the .mvc extension.

Uh oh, Houston! We have a problem

Of course, you’re going to want to be able to navigate to the web root for your project. Notice what happens when you navigate to /Iis6DemoWeb.

This is a bug in the Default.aspx.cs file included with our default template which I discovered as I was writing this walkthrough. We’ll fix it right away, but I can provide the fix here as it’s insanely easy.

Note: If you received a File Not Found error when visiting the root, then you might not have Default.aspx mapped as a default document. Follow these steps to add Default.aspx as a default document.

As I’ve written before, this file is necessary for IIS 6, IIS 7 Classic Mode, and pre SP1 Cassini, but not IIS 7 Integrated. So if you’re using Cassini with Visual Studio 2008 SP1 and deploying to IIS 7 Integrated, you can delete Default.aspxand its sub-files.

In the meanwhile, the fix is to make the following change.

Change:

HttpContext.Current.RewritePath(Request.ApplicationPath);

HttpContext.Current.RewritePath(Request.ApplicationPath, false);

If you created your website in the IIS root rather than a virtual application, you would never have noticed this issue. But in the virtual application, the URL to the stylesheet rendered contained the virtual application name, when it shouldn’t. Changing the second argument to false fixes this.

IIS6 Extension-less URLs

Ok, now we’re ready to try this with extension-less URLs using the infamous “Star mapping” or “Wildcard mapping” feature of IIS 6. I say infamous because there is a lot of concern over the performance implications of doing this. Of course, you should measure the performance of your site for yourself to determine if it is really a problem.

The first step is to go back to the Application Configuration Propertiesdialog like we did when configuring the .mvc ISAPI mapping (see, I told you that information might come in useful later).

Next to the Wildcard application maps section, click the Insert… button.

This brings up the wildcard application mapping dialog. Enter the path to theaspnet_isapi.dll. You can follow the trick we mentioned earlier for getting this path.

Don’t forget to uncheck the Verify that file exists checkbox! This is one of the most common mistakes people make.

If you’ve been following along everything in this post, you’ll need to go back and reset the routes in your Global.asax.cs file to the default routes. You no longer need the .mvc file extension in the routes. At this point, you can also remove Default.aspx if you’d like. It’s not needed.

Now when you browse your site, your URLs will not have a file extension as you can see in the following screenshots.

Final Tips

One thing to understand is that an ASP.NET project is scoped to the Website or Virtual Application in which it resides. For example, in the example I have here, we pointed a Virtual Application named IIS6DemoWeb to the directory containing my ASP.NET MVC web application.

Thus, only requests for that virtual application will be handled by my web application. I cannot make a request for http://localhost/ in this case and expect it to be handled by my application. Nor can I expect routing in this application to handle requests for another root directory such ashttp://localhost/not-my-app/.

This might seem like an obvious thing to say, but I know it trips some people up. Also, in the example I did here, I used a virtual application for demonstration purposes. It’s very easy to point a root Website in IIS to my application and run it in http://localhost/ rather than a virtual application. This is not a problem. I hope you found this helpful.

Did you know… How to add a Linked Item to a project

2008-12-06T03:13:00.000-08:00

This feature is helpful when you need a common file shared among projects, like a bitmap, readme, set of common tools and utilities, etc.

To add, right-click on the project in the solution explorer, and select Add – Existing Item. You’ll notice the “Add” button is one of those button-dropdowns. Drop down the Add button and select Add a link.

Now you have a linked item in your project as indicated by the shortcut icon.

The location of the linked file is saved in the project file. The location must be via the file system, either on different drives or UNC. No http or ftp.

Tracking User Activity

2008-12-06T03:09:00.001-08:00

Introduction

I like data. I go gaga over measurable metrics. Nothing makes me happier than storing information and then seeing it expressed in tables of numbers and colorful charts. Whenever I work on a web application I am always looking for interesting data to record and analyze, and the most interesting (and potentially profitable) data that every website owner should track are usage statistics. Web server log files and online tools like Google Analytics provide an array of useful metrics, including how many unique visitors accessed your site, what pages were the most popular, what days of the week and hours of the day represent peak demand, and so forth.

Many ASP.NET web applications support user accounts, enabling visitors to create an account and sign in to the site. With a little bit of effort you can track the activity of your logged on users. This can include recording activities such as what pages were visited as well as what actions were performed. Consider a page that allows a user to manage his profile. When first arriving at this page the activity log might add an entry like "Visiting the User Profile page." After updating his e-mail address, the activity log might record, "Changed e-mail address from scott@example.com to mitchell@example.com." Such usage tracking offers a deeper level of analysis than is possible with log files or online visitor statistic tools. Instead of data that report total number of visitors or how the average user is interacting with the site, user activity tracking can provide a very detailed view of how a particular individual is using the application and what actions he is performing while signed on to the site.

This article examines how to record your users' activities in a database table and display this information in a web page. A complete, working demo application that shows these techniques in action is available for download.

ASP.NET's Membership system makes it easy to create and manage user accounts. Many websites that use Membership are configured to use SqlMembershipProvider, a Membership provider that ships with the .NET Framework and stores user account information in a Microsoft SQL Server database. The demo application for this article uses SqlMembershipProvider, storing user account information along with the user activity log in a Microsoft SQL Server 2008 Express Edition database file (ASPNETDB.mdf), which you will find in the application's App_Data folder. For more information on using the Membership system refer to my ASP.NET Web Security tutorial series.

A Look at the Membership System's User Tracking Implementation

One of the lesser known features of ASP.NET's Membership system is that it has a built-in mechanism to track the last date and time each user has accessed the system. Each user account has a LastActivityDate property that records this information; the SqlMembershipProvider stores this value in the aspnet_Users table's LastActivityDate column in Coordinated Universal Time (UTC). This LastActivityDate value is automatically updated whenever a user signs in and whenever their user account information is accessed via the Membership.GetUser method. The LastActivityDate is used by the Membership system to determine how many users are online - theMembership.GetNumberOfUsersOnline method returns the number of users whose LastActivityDate is within a certain window of the current date and time (15 minutes, by default).

The Membership system's user tracking implementation is pretty limited as it only specifies the last date and time a user was active on the site. It does not indicate what the user was doing at that time or provide any sort of activity history. The activity logging system presented in this article overcomes these limitations.

Designing the User Activity Log Database Table

The first step in building any analysis tool is to determine what information to track. Different website usage analytic tools capture different information: web server logs typically record the filename of each requested page, the querystring, the date and time, and the HTTP status code, whereas online tools capture information of interest to the sales and marketing departments: visit durations, the geographical locations of the site's visitors, the number of unique visitors, entry and exit pages, and so on.

What information do we need to record when tracking the online activity of a website's logged on users? At a minimum we would need to log:

The activity being performed
The user performing the activity
The date and time of activity
The page being visited when the activity is performed

This information can be modeled in a single database table. Figure 1 shows such a table, which I've named ActivityLog. This table contains one record for each activity recorded for each user on the site.

Figure 1: The ActivityLog table models the activity log.

The ActivityLogID is of type uniqueidentifier and uniquely identifies each log entry. The UserId column identifies the user who performed the activity. (The UserId column in the aspnet_Users table is what uniquely identifies each user in the SqlMembershipProvider user store.) The Activity column describes the activity performed; PageUrl is the URL of the page where the activity was performed. Finally, ActivityDate is the date and time (in UTC) that the activity was performed.

The ActivityLog table is designed to have a record added for each activity performed by the user. Depending on the popularity of your website, this table can grow to include tens of thousands if not millions of records. You may want to consider implementing some mechanism to remove records older than a certain date, such as all activity log entries more than three months old. This could be accomplished by a SQL Job that executes nightly.

Logging User Activity

Web server log files automatically record each requested page; online usage statistic tools use cookies to track the pages users visit. Both of these logging mechanisms, once setup and configured, track visits to the site automatically without needed intervention from the web developer. The activity log is more flexible as it can be used to track any "activity," which may be page visits or user-instigated actions. Therefore, logging a user activity to the database involves writing code.

To help facilitate this process I created a custom base page class named BasePage that extends the System.Web.UI.Page class. BasePage includes a method named LogActivity(activity, recordPageUrl) that writes a record to the ActivityLog table with the specified activity and, if specified, the URL of the currently visited page.

The LogActivity method's code follows:

protected void LogActivity(string   
  
activity, bool recordPageUrl)  
{  
    if (Request.IsAuthenticated)  
    {  
        // Get information about the currently logged on user  
        MembershipUser currentUser = Membership.GetUser(false);  
        if (currentUser != null)  
        {  
            Guid userId = (Guid)currentUser.ProviderUserKey;  
            // Log the activity in the database  
            using (SqlConnection myConnection = new  
               SqlConnection(ConfigurationManager.  
               ConnectionStrings["MembershipConnectionString"].ConnectionString))  
            {  
                SqlCommand myCommand = new SqlCommand();  
                myCommand.CommandText = "usp_LogUserActivity";  
                myCommand.CommandType = CommandType.StoredProcedure;  
                myCommand.Connection = myConnection;  
                myCommand.Parameters.AddWithValue("@UserId", userId);  
                myCommand.Parameters.AddWithValue("@Activity", activity);  
                if (recordPageUrl)  
                    myCommand.Parameters.AddWithValue("@PageUrl", Request.RawUrl);  
                else  
                    myCommand.Parameters.AddWithValue("@PageUrl", DBNull.Value);  
                myConnection.Open();  
                myCommand.ExecuteNonQuery();  
                myConnection.Close();  
            }  
        }  
    }  
}  

The method starts by determining if the user visiting the page is authenticated. If so, it gets the user's information via the Membership class's GetUser method. If a user is returned, the stored procedure usp_LogUserActivity is called, passing in values for the @UserId, @Activity, and @PageUrl parameters. Note that if recordPageUrl is false, the @PageUrl parameter is set to a database NULL value; if it is true, the @PageUrl parameter is assigned the raw URL of the currently requested page, which includes the directories, filename, and querystring of the requested web page (i.e., /MyApp/Users/Default.aspx?ID=2).

The usp_LogUserActivity stored procedure starts by updating the LastActivityDate column in the aspnet_Users table. As a result, adding an entry to the user activity log is tantamount to retrieving the user's information through the Membership system. Following the update to the LastActivityDate, the usp_LogUserActivity stored procedure inserts a record into the ActivityLog table. This update and insert are atomic as they are performed under the umbrella of a transaction. For background on transactions and using SQL Server's TRY...CATCH blocks seeMaintaining Database Consistency with Transactions and TRY...CATCH in SQL Server.

ALTER PROCEDURE dbo.usp_LogUserActivity  
(  
    @UserId     uniqueidentifier,  
    @Activity   nvarchar(100),  
    @PageUrl    nvarchar(100)  
)  
AS  
BEGIN TRY  
   BEGIN TRANSACTION    -- Start the transaction  
    DECLARE @CurrentTimeUtc datetime  
    SET @CurrentTimeUtc = getutcdate()  
   -- Update the LastActivityDate in aspnet_Users  
    UPDATE  dbo.aspnet_Users  
    SET     LastActivityDate = @CurrentTimeUtc  
    WHERE   @UserId = UserId  
    -- Insert activity record for user  
    INSERT INTO ActivityLog(UserId, Activity, PageUrl, ActivityDate)  
    VALUES(@UserId, @Activity, @PageUrl, @CurrentTimeUtc)  
   -- If we reach here, success!  
   COMMIT  
END TRY  
BEGIN CATCH  
  -- Whoops, there was an error  
  IF @@TRANCOUNT > 0  
     ROLLBACK  
  -- Raise an error with the details of the exception  
  DECLARE @ErrMsg nvarchar(4000), @ErrSeverity int  
  SELECT @ErrMsg = ERROR_MESSAGE(),  
         @ErrSeverity = ERROR_SEVERITY()  
  RAISERROR(@ErrMsg, @ErrSeverity, 1)  
END CATCH  

With the BasePage class complete, the final step is to have the ASP.NET pages in the site derive from BasePage (rather than from System.Web.UI.Page). Once this has been done you can call the LogActivity method from any page. For example, the homepage (~/Default.aspx) has the following code for its Page_Load event handler:

protected void Page_Load(object sender, EventArgs e)  
{  
    if (!Page.IsPostBack)  
    {  
        base.LogActivity("Visiting the homepage...", true);  
    }  
}  

The LogActivity method can be called from any event handler in those ASP.NET pages that derive from BasePage. Call LogActivity from the Page_Load event handler to log information when a page is first visited. You can additionally call LogActivity when the user clicks a button to log that they've performed a particular action (such as editing or deleting a record from some database table). All of the ASP.NET pages in the demo application derive from the BasePage class, and most include at least one call to the LogActivity method.

Displaying a Particular User's Activity History

The activity log provides a complete history of each user's activity on the site. The demo application includes a page named ActivityHistoryByUser.aspx that displays the complete history in a paged grid for a particular user. Figure 2 shows a screen shot of ActivityHistoryByUser.aspx in action.

The GridView controls used in the web pages in this tutorial use default paging, which is easy to implement but inefficient when paging through a large number of records. Because the activity log may contain thousands of records for each user account, the GridView controls should be retooled to use custom paging unless some mechanism is put into place to periodically cull old activity log entries from the table or if only recent activity log records are displayed in the grid. For more information on custom paging see Custom Paging in ASP.NET.

Figure 2: Scott's activity history is displayed in a grid.

Each activity in the left column is displayed as a hyperlink that links to the activity's PageUrl value (if such a value exists). The Last Updated column shows the date the activity was performed. For activities older than a week, the date the activity was performed is displayed. If the activity occurred more recently then a human-friendly message, such as "2 days ago" or "6 minutes ago," is displayed in place of the date and time. (This display formatting is handled by the FormatLastUpdatedDate method in the BasePage class.)

The grid is populated by the records returned from the usp_GetUserActivityLog stored procedure. As the following markup shows, this stored procedure returns the ActivityLog entries for a particular user ordered from the most recent entries to the oldest.

ALTER   
  
PROCEDURE dbo.usp_GetUserActivityLog  
(  
    @UserID uniqueidentifier  
)  
AS  
DECLARE @CurrentDateUtc datetime  
SET @CurrentDateUtc = getutcdate()  
SELECT ActivityLogID, Activity, PageUrl, ActivityDate, @CurrentDateUtc as CurrentDate  
FROM ActivityLog  
WHERE UserID = @UserID  
ORDER BY ActivityDate DESC  

Viewing the Online Users and their Last Performed Activity

Many websites that support user accounts have a page that lists what users are currently online and what activity they last performed. As noted earlier, the Membership system automatically records each user's last active date and time and provides a method for determining how many users have been active within a specified time window. The Membership's built-in system does not include what activity the user last performed, but this information is captured by the ActivityLog table.

I added a stored procedure to the database named usp_GetCurrentActivityForOnlineUsers that returns the list of users who are currently online along with their most recent activity. This stored procedure takes in a single input parameter, @MinutesSinceLastInactive, which is the number of minutes that has elapsed since a user has been active in the system and is still considered "online." For example, a value of 15 means that any user whoseLastActivityDate is within 15 minutes of the current date and time is considered "online," whereas those users whose LastActivityDate is outside of this window are considered "offline."

The usp_GetCurrentActivityForOnlineUsers stored procedure starts by determining what time is the cutoff for a user to be considered "online." It then queries the aspnet_Users and ActivityLog tables to retrieve the username of online users along with information about their last activity.

ALTER PROCEDURE   
  
dbo.usp_GetCurrentActivityForOnlineUsers  
(  
    @MinutesSinceLastInactive   int   
)  
AS  
DECLARE @CurrentTimeUtc datetime  
SET @CurrentTimeUtc = getutcdate()  
DECLARE @DateActive datetime  
SELECT  @DateActive = DATEADD(minute,  -(@MinutesSinceLastInactive), @CurrentTimeUtc)  
SELECT  act.UserId,  
        u.UserName,   
        act.Activity,  
        act.PageUrl,  
        act.ActivityDate,  
        @CurrentTimeUtc as CurrentDate  
FROM    dbo.aspnet_Users u(NOLOCK)  
    INNER JOIN dbo.ActivityLog act(NOLOCK) ON  
        act.UserId = u.UserId  
WHERE   u.LastActivityDate > @DateActive AND  
        act.ActivityDate = u.LastActivityDate  
ORDER BY act.ActivityDate DESC  

The WhoIsOnline.aspx page displays the results from this stored procedure in a grid (see Figure 3).

Figure 3: Those users currently online are listed along with their most recent activity.

Conclusion

Web server log files and online usage analysis tools are helpful in determining and evaluating macroscopic usage patterns. Unfortunately, these tools cannot provide a detailed view of how a particular user is interacting with your site. Nor can they provide live, up to the second activity information that can be used in your application to show who is currently online and what they are doing. Such deep usage analysis and real-time statistics are possible on websites that support user accounts.

ASP.NET's Membership system greatly simplifies the process of setting up, creating, and managing user accounts. However, the Membership system only tracks when each user's last activity was on the site; it does not log the activity performed or maintain an activity history. As examined in this article, it is possible to build your own user activity log with a little bit of elbow grease.

Happy Programming!

References

Nokia N79

2008-12-02T10:31:00.000-08:00

Device Description:

The Nokia N79 is a GSM/WCDMA dual-mode multimedia computer supporting WCDMA/HSDPA, EGSM, and WLAN. Change the Xpress-on smart covers that automatically change the theme when attached. Use the Nokia N79 to connect to mobile broadband using WLAN or HSDPA (3.5G). Find directions and locations with the integrated A-GPS and included maps. Take photos with a 5-megapixel autofocus camera with a dual LED flash and automatic location tagging of images and videos. Enjoy videos, music, and graphics on the 2.4” QVGA display with orientation sensor. Additional features include UPnP, Bluetooth 2.0 +EDR, and USB 2.0 High-Speed.

Compare with other device(s)

Technical Specs
Developer Platform	S60 3rd Edition, Feature Pack 2
Operating System	Symbian OS v9.3
Resolution	240 x 320
General
Resolution	240 x 320
Color Depth	24 bit
Size	110 x 49 x 15 mm
Weight	97 g
Input Methods	3 Labeled Soft Keys 5-way Scrolling Grid Key Mat Navi Wheel
Frequency Band	GSM 1800 GSM 1900 GSM 850 GSM 900 WCDMA 2100 WCDMA 900
Regional Availability	Africa Americas Asia-Pacific Europe Middle East
Data Bearer	CSD Dual Transfer Mode (MSC 11) EGPRS GPRS HSCSD HSDPA WCDMA
CPU Count	Single CPU
CPU Type	ARM 11
CPU Clock Rate	369 MHz
UAProf Link	Profile 1 Profile 2 Profile 3
Consumer Link	Product Home Page
Developer Link	Developer Home Page
Extra Features
Extra Features	Accelerometer Sensor FOTA Firmware over the Air Flight Mode Internet Radio Nokia Maps OMA Domain Name System (DNS) 1.0 On-Demand Paging Open C API's PoC (Push-to-talk over Cellular) Stereo FM Radio Stereo Handsfree Speakers Still Image Editor SyncML TV Out Themes Visual Radio
GPS Features	A-GPS
APIs
Java Technology	CLDC 1.1 IAP Info API JSR 135 Mobile Media API JSR 172 Web Services API JSR 177 Security and Trust Services API JSR 179 Location API JSR 180 SIP API JSR 184 Mobile 3D Graphics API JSR 185 JTWI JSR 205 Wireless Messaging API JSR 226 Scalable 2D Vector Graphics API JSR 234 Advanced Multimedia Supplements JSR 248 Mobile Service Architecture for CLDC JSR 75 FileConnection and PIM API JSR 82 Bluetooth API v1.1 MIDP 2.1 Nokia UI API eSWT UI API
Java API Access Permissions	Java API Access Permissions
Symbian Certificates	Symbian A Symbian B Symbian C Symbian D UTI Root
Product ID	0x2000DA64
Browser & Flash
Browser	HTML over TCP/IP OSS Browser WAP 2.0 Web Runtime XHTML over TCP/IP
Flash Lite	Flash Lite 3.0
Multimedia
Camera Resolution	2584 x 1938
Digital Zoom	20 x
Sensor	CMOS 5.0 Megapixel
Focal length	5.2 mm
F-Stop/Aperture	f/2.8
Focus range	10 cm to infinity
Image Format	JPEG/Exif
Camera Features	Auto Focus, Carl Zeiss Optics, Flash, Red-Eye Reduction, Self Timer, Video Stabilization
Video Resolution	640 x 480
Video Frame Rate	30 fps
Video Zoom	8 x
Video Format	H.263, MPEG-4
Secondary Camera Resolution	352 x 288
Secondary Camera Digital Zoom	2 x
Secondary Camera Image Format	JPEG
Secondary Camera Video Format	H.263
Video Features	Video Player Video Recorder Video Ringtones Video Sharing Video Streaming
Video Formats	3GPP formats (H.263) Flash Video H.264/AVC MPEG-4 RealVideo 7,8,9/10 WMV
Graphics Formats	BMP, EXIF, GIF87a, GIF89a, JPEG, JPEG 2000, PNG, WBMP
Audio Features	Audio Equalizer Audio Recording AAC stereo, 48kHz Audio Streaming FM Transmitter (88.1 - 107.9 MHz) Music Player Stereo
Audio Formats	AAC, AAC+, AMR-NB, AMR-WB, M4A, MIDI Tones (poly 64), MP3, MP4, Mobile XMF, RealAudio 7,8,10, SP-MIDI, True tones, WAV, WMA, eAAC+
Memory Functions
Max User Storage	50 MB
Memory Card	Micro SD
Max Memory Card Size	8 GB
Maximum Heap Size	Unlimited
Maximum JAR Size	Unlimited
Connectivity
Local Connectivity	Bluetooth 2.0 +EDR Bluetooth Stereo Audio DLNA Certification Micro USB Mini Stereo Plug 3.5mm Nokia AV 3.5mm Nokia microUSB Cable CA-101 UPnP USB 2.0 High-Speed USB Mass Storage WLAN
WLAN support	802.11b/g WEP WPA WPA2 (AES/TKIP)
Bluetooth Profiles	A2DP, AVRCP, BIP, BPP, DI, DUN, FTP, GAP, GAVDP, GOEP, HFP, HID, HSP, OPP, PBAP, SAP, SDP, SPP
Messaging
Messaging	IM MMS+SMIL SMS
Email Protocol	IMAP4 POP3 SMTP
Email Solution	Mail for Exchange Nokia Intellisync Wireless Email OMA E-mail Notification v1.0
Messaging Feature	OMA Instant Messaging and Presence Service v1.1 OMA Instant Messaging and Presence Service v1.2.1 OMA Multimedia Messaging Service v1.2
Document Formats	Excel, PDF, Powerpoint, Word, Zip
Power Management
Power Management	2.0mm Charger Connector
Battery	BL-6F 3.7V 1200 mAh
GSM Talk Time	5.5 hours
WCDMA Talk Time	3.5 hours
VoIP Talk Time	4 hours
GSM Standby Time	372 hours
WCDMA Standby Time	406 hours
Other
OMA Device Management	OMA Client Provisioning v1.1 OMA Device Management v1.1.2
OMA Data Synchronization	OMA Data Synchronization v1.2
Digital Rights Management	OMA DRM Forward Lock OMA DRM v1.0 OMA DRM v2.0 OMA DRM v2.1 Windows Media DRM 10
DRM Delivery Method	HTTP Download MMS OMA Download v1.0
Web Service	Liberty Alliance ID-WSF 1.1 OMA WS Network Identity 1.0 WS-I Basic Profile 1.0/1.1

Tools

The main Tools & SDKs page www.forum.nokia.com/tools provides all the tools & SDKs in an easy to access form. The page also includes Getting Started -articles giving an overview of the tools and SDKs.

Carbide.c++ v1.3, the development tool for C++ for Symbian OS and Open C developers
Carbide.c++ is a powerful family of mobile development tools built on the Eclipse framework. Family members include: Carbide.c++ OEM Edition for device creation users Carbide.c++ Professional Edition for developers working with pre-production devices Carbide.c++ Developer Edition for application development on production phones Carbide.c++ Express, available as a no-cost download to introduce developers to mobile experience

Carbide.ui Theme Edition
Carbide.ui Theme Edition enables the creation and editing of themes for S60 and Series 40 devices. Carbide.ui provides professionals and hobbyists alike with access to more than 1,000 customizable elements in the S60 UI, which makes the S60 UI the most customizable UI available.

Recommended SDK(s)

OpenGL ES 1.1 Plug-in
This early technology plug-in for S60 3rd edition SDK for Symbian OS, for C, enables the development of OpenGL ES 1.1 applications with N93. N93 is the first Nokia multimedia computer with HW accelerated 3D graphics/OpenGL ES 1.1 support. This plug-in enables the full usage of the native 3D graphics features supported in N93. The content of this plug-in will be a part of S60 R3.1 SDK.

S60 Platform SDKs for Symbian OS, for Java™
S60 Platform SDK for Symbian OS, for Java™ MIDP allows developers to quickly and efficiently run and test Java applications for devices built on the S60 platform. Using a Java™ IDE, development with the SDK is hosted on a PC.

S60 Platform SDKs for Symbian OS, for C++
The S60 SDKs for Symbian OS enable application development for devices based on the S60 platform using C++. The SDK includes all key resources needed for application development, such as documentation, API reference, and an emulator. An IDE is not included; Carbide.c++ is recommended.

Hosting an “Indigo” (WCF) Service

2008-11-28T00:39:00.002-08:00

Table of Contents:

Introduction

Hosting Environments

· ASMX Services

· WCF Services

· Different Hosting Environments

WAS Hosting Environment

· A Simple Hosted Service

· Service Configuration

· Service Addressing

· Service Activation

· Service Recycling

Let me start with something simple for this topic. I first make a few assumptions here:

You have used Microsoft Internet Information Services (IIS).
You are familiar with .NET Programming with Common Language Runtime (CLR) and ASP.NET.
You have heard of Microsoft Windows Communications Foundation (WCF), code-named “Indigo”.

That is all what you need to know before reading the following!

Below I will write about how to host a WCF service in a special “hosting” environment.

Introduction

There are tons of articles and blogs out there talking about Service Oriented Architecture (SOA), Web Services, and WCF. Never mind if you have not read them. So I will make things as simple as possible. Basically, WCF, as the next generation of service-oriented programming platform, provides a set of .NET APIs in its Version 1 (V1) for developers to use. It will be released as part of a larger package WinFX. You can download the most recent PDC release fromhere.

Every service-oriented programming model is also a client-server model. WCF has no difference. Both the client and service counterparts of WCF are based on the so-called “ABC” model: Address, Binding, and Contract. People also call this as “WHW” model: Address stands for “Where”, Binding stands for “How”, and Contract stands for “What”. Among the three, Binding is the most complicated part in this model. It tells WCF how to transfer data between the client and the service:

What transport do we use: HTTP, TCP, MSMQ, Named Pipe, etc?
What encodings do we use for the data to be encoded?
What security mechanisms do we use for the underlying channels?
Etc.

For each WCF service, there is a host that manages service instances and lifetime. The base type of the host is System.ServiceModel.ServiceHost. It provides events and extensibility points for you to programming with. Actually I am lying here. ServiceHost is not the most basic service host type, but System.ServiceModel.ServiceHostBase is. However, you will never touch this base type if you do not want to re-create the whole channel stack to replace WCF underlying implementations.

How far have I diverted from my topic? Aren’t we talking about WCF service hosting? No, not yet! The concept of “host” has relative meanings in different programming plug-in layers. The “host” that I will talk about here has a broader meaning: it is application-level “host”. That is, a host is an application that loads one or more WCF ServiceHosts, which we will call services in the following, and manages their lifetime. In some cases, it provides an environment that works as the entry point for all messages that are routed to the services. Am I clear here? If not, please read on.

Hosting Environments

There are different types of hosting environments for WCF services. To understand how these hosting environments work, we need to go back to see how the predecessor of WCF, a.k.a., ASMX works.

ASMX Services

When ASP.NET V1 was shipped, a Web service framework known as ASMX was introduced. It is tightly integrated with the ASP.NET HTTP pipeline. This pipeline provides the hosting environment to ASMX services and it is almost always hosted inside ASP.NET applications which are managed by IIS. In this way, ASMX services can leverage the advantages of ASP.NET applications such as process management, application recycling, configuration and deployment, and extensibility points provided by ASP.NET HTTP pipeline.

It is not required to have IIS to run ASMX services. For example, you can use the ASP.NET Cassini sample web server to host an ASP.NET application and thus ASMX services. You also build a web server into your own application to host the ASP.NET pipeline using the managed HTTP.sys utility System.Net.HttpListener(see Run ASMX without IIS).

However, ASMX services cannot run without the ASP.NET HTTP pipeline. Even though you can integrate the pipeline into your application as above, you still need to think of the ASMX services as being in a different world, that is, they have their own configuration and deployment which are quite web-flavored. In this sense, WCF services go one big step beyond to make service-oriented programming real.

WCF Services

The fact that ASMX services are tightly coupled with ASP.NET HTTP pipeline is due to the flat and passive HTTP request handling mechanism. HTTP requests received from IIS are passed on to ASP.NET pipeline and then are consumed by service methods.

WCF services, however, are based on a strictly layered model to break this paradigm. Roughly speaking, there are three different layers for WCF services:

ServiceModel layer
Channel layer
Transport layer

This layered model is similar as the Open System Interconnection (OSI) model. The lowest Transport layer is responsible for listening and receiving requests and converting the received data into “Messages”. A Message is a cross layer data packet that travels all of the layers to the top. The Channel layer provides a Message processing framework for different service requirements. In the real implementation, it actually consists of one or more sub-channel layers such as Basic layer, Security layer, ReliableMessaging layer, Transaction layer, etc. The top ServiceModel layer is the application layer that manages service instances and invokes service operations. It provides Object Models (OM) for people to program with.

In this layered model of WCF services, the top SericeModel layer is also responsible for building the lower level layers in different hosting environments. It also makes the Transport layer to be freely chosen among different communication protocols. This is why it does not rely on the ASP.NET HTTP pipeline as ASMX services does.

Different Hosting Environments

As mentioned above, WCF services are hosted by a ServiceHost. Ideally, any application or environment can create ServiceHost to host WCF services. In reality, we classify the different environments into three categories:

Windows Activation Service (WAS) hosting environment
EXE applications
NT Services

The WAS hosting environment is a broad concept that extends the ASP.NET HTTP pipeline hosting concept for ASMX services. WAS is an NT service inWindows Vista. It is separated out from the legacy IIS as a standalone Windows component that provides protocol-agnostic activation mechanism for different protocols besides HTTP. The IIS, Cassini, and any custom Web Server flavored hosting environments also fall into this category since they share the same WCF service deployment and activation mechanism. I will talk about this more in later sections.

You can easily host a WCF service in an EXE application so that you can control the lifetime of the ServiceHost. Furthermore, the WCF service shares the same configuration file with the application. This hosting environment is mostly useful when you also build your client code into the application. A good example is that a sophisticated business application with 3-tier architecture can have WCF services to pass messages between different layers.

NT Services are special EXE applications which are long running and the lifetime is controlled by Service Control Manager (SCM). Because of the long running behavior, you need to be careful of all of different requirements for writing an NT Service: security, reliability, and performance. You can use Microsoft Visual Studio to create managed NT Services with “Windows Service” project type.

WAS Hosting Environment

As mentioned above, a WCF service works similarly as an ASMX Service. For HTTP protocol, it relies on ASP.NET HTTP pipeline to transfer data. For non-HTTP protocols such as Net.Tcp, Net.Pipe, and Net.Msmq etc, it relies on the extensibility points, i.e., ProcessProtocolHandler (PPH) and AppDomainProtocolHandler (ADPH), of ASP.NET to transfer data. We will use the term “protocol handler” interchangeably to refer to either the ASP.NET HTTP pipeline or the ADPH. In the context of this writing, WCF services hosted in this environment are called WAS hosted services or simply called hosted services, and in contrast, services hosted in NT Services or EXE applications are calledself-hosted services.

Let’s first take a look at a simple hosted service and see how it works.

A Simple Hosted Service

A hosted service requires a physical service file with extension “.svc” to be associated with it. Here is the content of a simple service file HelloWorld.svc:

<%@Service Language="C#" Class="HelloWorld.HelloService" %>

using System;

using System.ServiceModel;

namespace HelloWorld

{

[ServiceContract]

public interface IHelloContract

{

[OperationContract]

string Hello(string greeting);

}

[ServiceBehavior]

class HelloService : IHelloContract

{

public string Hello(string greeting)

{

return "You said: " + greeting;

}

This file has a Service directive which is enclosed in the “<% %>” block and it also contains inline C# code. The Service directive tells the hosting environment which Service this file points to.

Just as ASMX services, the code can be compiled into a DLL that is deployed to the Global Assembly Cache (GAC), or to the application’s “\bin” directory, or it can be put in a C# file under the application’s “\App_Code” directory.

With this service file, we have defined a service contract IHelloContract and the service implementation. However, the service still does not have an endpoint defined yet. You can either define an endpoint declaratively through the configuration file “web.config” or imperatively through code. The latter will be covered separately in a different blog later.

Service Configuration

The service configuration inside the web.config file is very similar as that of self-hosted services. Here is an example of web.config file for the above service:

xml version="1.0" encoding="utf-8"?>

<system.serviceModel>

<endpoint binding="basicHttpBinding"

contract="HelloWorld.IHelloContract" />

service>

services>

system.serviceModel>

configuration>

I need to point out a few points for this config file:

1) Service Type Attribute: The service type “HelloWorld.HelloService” specified here plays as a lookup key for the corresponding HelloWorld.svc. It tells the hosting environment which service will take the configuration specified here.

2) Endpoint Address: I did not specify the “address” of the endpoint here. The endpoint address is the same as the base address in this case. I will expand this in the next section.

3) Nested web.config: The service configuration can be specified in nested web.config files. For ASP.NET applications, a web.config file can locate in any sub-directories or virtual web directories as well as the root of the virtual application. All of the settings in the nested web.config files are merged for the virtual ancestors of the directory where the .svc file locates.

Service Addressing

The .svc file does not contain much useful information except for providing the service type which is also specified in the web.config file. Then why do we need .svc files after all? The main reason is that we need them to provide intuitive addressing model.

Suppose that we drop the above HelloWorld.svc file into a virtual application “/test”, we automatically have the following base address for the service:

http://localhost/test/HelloWorld.svc

You can enable different protocols for a single ASP.NET application. Each protocol needs to have a protocol binding for the whole web site. For IIS6 and below, the only protocol that is supported is HTTP (which implies HTTPS).

The WAS hosting environment looks up all enabled protocols for the ASP.NET application and generates the base addresses for the hosted service. Each base address has the following format:

://[:]//.svc

You can access the base addresses through the ServiceHostBase.BaseAddresses property. In WCF V1, only one base address is supported for each protocol. So if there are two or more bindings for HTTP is specified, you will get an ArgumentException on the service side with error message “Collection already contains an address with scheme http”.

Note: It is NOT recommended to specify an absolute address (with protocol scheme included) to the endpoint in web.config, otherwise, you will get AddressAccessDeniedException on the service side if the address does not match the service base address up to the application path () or EndpiontNotFoundException if you happen to match the application path but not the service path.

Service Activation

The WAS hosting environment is represented by the public type System.ServiceModel.ServiceHostingEnvironment. It is responsible for service activation, that is,

· It finds the service compilation information from System.Web.Compilation.BuildManager

· It creates the ServiceHost instance to host the service with compilation information.

· It then calls ServiceHost.Open to build the layers.

· It then caches the service and manages its lifetime inside the AppDomain.

This whole process is exposed through the following public method:

public static void EnsureServiceAvailable(stringvirtualPath)

This API is protocol agnostic. It is an extensible point for a custom protocol handler to activate the service.

The service activation process has the following characteristics:

1) Activation on demand: A WCF service is activated in the AppDomain only if EnsureServiceAvailable is called by one protocol handler for that service. Once it is activated, it will be active in the AppDomain until the AppDomain is unloaded.

2) Activation once for all: A WCF service can be activated from any protocol handler. Once it is activated, it is activated for all endpoints and thus all protocols. So when a second protocol handler calls EnsureServiceAvailable, it is a no-op as the service has been activated.

Service Recycling

Hosted WCF services enjoy all of the features for ASP.NET applications. One of the major feature is application recycling including AppDomain recycling and process (or AppPool) recycling. There are different factors that can cause application recycling to happen. See “Recycling Application Pool Settings” for more information about process recycling. When the worker process is recycled, all of the AppDomains in that process are also recycled. The configuration setting HostingEnvironmentSection.IdleTimeout can control AppDomain recycling. Also an AppDomain can be recycled if critical files for the application are changed. These files include web.config, assemblies in the “\bin” directory, code files in the “\App_Code” directory, etc.

Whenever a .svc file is modified in application, the AppDomain is also recycled. This is to simplify the service recycling mechanism. When the AppDomain is recycled, the ServiceHostingEnvironment tries to close all of the cached WCF services in a timely manner. Services not closed timely are aborted at the end. The timeout is controlled by the HostingEnvironmentSection.ShutdownTimeoutproperty.

The drawback of service recycling is that all of the sessionful data is lost. This means that Security and ReliableMessaging break when recycling happens. The workaround is to leverage the ASP.NET state service features by enabling AspNetCompatibility mode. I will expand on this in a later blog.

ASP.NET Async Pages vs Async WCF Service Operation

2008-11-28T00:39:00.001-08:00

In Dmitry’s blog, he mentioned about how to write ASP.NET async pages with ASP.NET 2.0. Basically, the server page can handle the request asynchronously without blocking the request thread and the server thread can be returned to the thread pool to handle other requests.

WCF is quite flexible in supporting asynchronous programming. Actually the client and the service can use any pattern (sync or asnc) in their own way to perform the same operation. For example, you can use the following service contract with an async operation in it:

[ServiceContract(Namespace = "http://tempuri.org", Name = " HelloService")]

interface IHelloService

{

[OperationContract(IsOneWay = false, AsyncPattern = true)]

IAsyncResult BeginHello(string text, AsyncCallbackcallback, object state);

string EndHello(IAsyncResult result);

}

This allows you to implement the service operation in the same way as ASP.NET async pages.

On the client side, you can access the service either from an async call or a sync call. For example, you can have a sync client to access the above async service operation with the following client contract:

[ServiceContract(Namespace = "http://tempuri.org", Name ="HelloService")]

interface IHelloService

{

[OperationContract(IsOneWay = false)]

string Hello(string text);

}

Cannot Find Server (404) or Get Plain Text for WCF .svc Files From IIS?

2008-11-28T00:37:00.002-08:00

Question

After upgrading WCF (or NetFx-3.0) from an older beta version to RC1, I get “Page Not Found” (404) error or get the plain text content of the .svc file for .svc files. Is .svc extension removed from IIS?

Why?

If you installed WCF or NetFx-3.0 RC1 or later versions, you may get this problem. On Windows XP SP2, you may get the plain text of the .svc file. On Windows 2003 Server, you may get error like “Cannot find the page” (404) error. It looks like .svc extension is not supported in IIS.

Is .svc mapping removed from IIS? No. Definitely not! The reason why you saw this is because your IIS Metabase got messed up by an earlier WCF installer due to a nasty bug. You need to clean up the IIS Metabase manually so that it works again. How? Please keep on reading.

Before RC1, there was a bug in WCF installer. It accidentally populates .svc mapping to every path/node in IIS Metabase. This messed up the Metabase and has potential security concern. Fortunately, we found this issue in RC1 and fixed it. By fixing it, we only install .svc mapping to the template of the root /W3SVC of IIS Metabase. However, those machines with earlier WCF beta versions installed still have the messy ScriptMaps. They stop the inheritance of the .svc ScriptMaps from the template at the root /W3SVC. This is especially true for the “Default Web Site” and its virtual applications.

If you create a new web site with WCF RC1 installed, you won’t have this problem for that web site.

Solutions

Here are different ways that can help you to resolve the problem:

· Download tool: CleanIISScriptMaps.exe

Please find the tool “CleanIISScriptMaps.exe” in the attached zip file. The source for the tool is also included. You also find this tool and corresponding information on http://wcf.netfx3.com/files/folders/product_team/entry5648.aspx. The usage for this tool is simple, just run it without any argument from any command window. After running it, everything should just work fine. You don’t need to rerun any other setup.

If you find that .svc is still not supported for some virtual directories but you want them to be supported as well, you can run the tool with more options to explicitly remove the ScriptMaps properties from those paths. Here is the full usage of the tool:

Usage: CleanIISScriptMaps

Options:

By default, the tool removes redundant ScriptMaps properties.

/f Remove ScriptMaps from all nodes in IIS Metabase except for

the root "/W3SVC".

/p Prompt for confirmation when removing ScriptMaps at a node

that is different than that of the root "/W3SVC".

/v Print out verbose information.

/? Print this help.

· Reinstall IIS or re-create web sites

You can uninstall IIS and reinstall it so that the IIS Metabase is cleaned up. Then you will need to run the WCF install tool manually as following:

"%windir%\Microsoft.NET\Framework\v3.0\Windows Communication Foundation\ServiceModelReg.exe" /r /y

If you are running Windows 2003 Server, you may be able to delete the “Default Web Site” and re-create it. The problem will be fixed as well.

· Install .svc manually as a temporary workaround

You can run the following command to install .svc mapping manually. However, this does not clean up the mess of the IIS Metabase. You will see the same problem again when you install newer WCF. So this is the least recommended approach comparing to the above two options:

"%windir%\Microsoft.NET\Framework\v3.0\Windows Communication Foundation\ServiceModelReg.exe" /s:W3SVC

Though this does not clean up the Metabase for you, it does not mess up new web sites.

How to use WSDualHttpBinding on Windows XP for Hosted Services

2008-11-28T00:37:00.001-08:00

On Windows XP, Internet Information Service (IIS) does not use HTTP.syswhich is the HTTP driver that can be used to share HTTP traffic on the same port by multiple applications. This means that when IIS is running, the default port 80 is taken by IIS and no other applications can use it.

So if you use WSDualHttpBinding for your service, the client won’t be able to open the listener against the default port 80 on the same machine and it would fail with AddressAlreadyInUseException.

To workaround this, you need to change the ClientBaseAddress of WSDualHttpBinding on the client side so that it uses a different port than the one that IIS is using. From client config, you can do the following:

<system.serviceModel>

<endpoint name="WSDualOnXP"

address="http://localhost/WSDualOnXP/HelloWorld.svc"

binding="wsDualHttpBinding"

bindingConfiguration="WSDualOnXP"

contract="HelloWorldClient.IHelloContract" />

client>

wsDualHttpBinding>

bindings>

system.serviceModel>

From code, you can also set the ClientBaseAddress:

WSDualHttpBinding binding = new WSDualHttpBinding();

binding.ClientBaseAddress ="http://localhost:808/WSDualOnXP/";

On the server side, you don’t have to specify the ClientBaseAddress since the addressing correlation is automatically done by WCF infrastructure.

WinFX February CTP is released!

2008-11-28T00:36:00.000-08:00

GREAT NEWS! The WinFX February CTP has just been released today and can be downloaded from here. Here is the readme document. This CTP has consumed a lot of customer feedback and thus brings quite a lot of breaking changes over the January one. The detailed WCF breaking changes can be found here. The changes include namespaces, APIs, configuration, setup, etc. Ed Pinto has a quick blog entry on this.

The biggest change to WebHost is that the .svc file format is changed. This was actually reflected in my earlier blog entries.

Before:

<%@Service language="C#" Debug="true"class="Microsoft.ServiceModel.Samples.CalculatorService" %>

After:

<%@ServiceHost language="C#" Debug="true"Service="Microsoft.ServiceModel.Samples.CalculatorService" %>

You can also use the factory model to create your own ServiceHost with the following advanced syntax:

<%@ServiceHost language="C#" Debug="true"Factory="Microsoft.ServiceModel.Samples.CalculatorServiceHostFactory" Service="Microsoft.ServiceModel.Samples.CalculatorService" %>

The Visual Studio CTP for this WinFX can be found at this link.

The WinFX SDK is also released as part of the larger Windows SDK which includes pre-release documentation, samples, and tools for both Win32® and WinFX® in Windows Vista.

What is IIS7?

2008-11-28T00:34:00.002-08:00

What is IIS7? What is the difference between IIS6 and IIS7? Here are the simple answers:

§ IIS7 is a new revision (version 7.0) of the Internet Information Services that is shipped on Windows Vista and the next Windows Server version.

§ The most attractive features of IIS7 are: modular design (thanks to the new Windows componentization technology first introduced in Windows Vista), extensible architecture (with public web server APIs), and unified distributed configuration system.

§ Another big change to IIS7 is that it first introduced a new NT service “Windows Process Activation Service” (WAS). WAS manages application pool configuration and worker processes. This enables process activation through both HTTP and non-HTTP transports.

More details about IIS7 can be found in the IIS7 public web site:http://www.iis.net/.

When people asked me how to host WCF services on IIS7? I would always say: it is the same as on IIS6. Well, this is generally correct. People still kept on hitting unique problems on IIS7. I will expand this in more details in my future blog entries.

Virtual Application vs Virtual Directory

2008-11-28T00:34:00.001-08:00

People are always confused by these two IIS concepts, especially for the new IIS7/WAS. These are not new concepts. They are available since IIS6 on Windows 2003 Server. However the terms were misused in IIS6 and they are corrected in IIS7 in Windows Vista and higher versions of Windows.

Virtual Application

What is it?

The term “virtual application” is a fundamental concept for IIS and ASP.NET. Here is the definition in my own words: a virtual application is a construction unit of a web site that participates protocol listening and process management. It can be uniquely identified by its absolute virtual path from that web site. For example, you can create a virtual application with virtual path “/foo” in the “Default Web Site”. For simplicity, we also call virtual application as "Default Web Site/foo" or simply “/foo”. Every web site has at least one virtual application, a.k.a, the root virtual application “/”.

A web site can be uniquely identified by its site ID. All of the web sites are under the same root “/W3SVC”. So each web site can be represented in the format of “/W3SVC/”. For example, the “Default Web Site” can be represented as “/W3SVC/1”. With this, we can uniquely identify a virtual application with its full path, for example,

/W3SVC/1/Root/foo

If you have the IIS6 scripting tool “adsutil.vbs” installed, you would be able to check the settings of the virtual application with the following command:

cscript %systemdrive%\inetpub\adminscripts\adsutil.vbs enum /W3SVC/1/Root/foo

Protocol Listening

When you create a virtual application, you would expect your new virtual application to receive requests that are dedicated to it. There are two aspects of “protocol listening”:

For a particular protocol (for example HTTP), a web site is nothing but a list of virtual applications. This means that the protocol activation service (which is IIS or W3SVC in the HTTP case) registers a list of Urls in the protocol listener service (which is HTTP.sys driver for HTTP). Each of this Url is associated with a virtual application.
You can specify which protocol is enabled for a virtual application. In IIS6, you can specify HTTP or HTTPS. In IIS7, however, you can specify any protocol(s) through the “enabledProtocols” property of the virtual application. For example, you can specify protocols “net.tcp”, “net.pipe”, “net.msmq”, or “msmq.formatname” that are implemented by WCF.

Application Pool

The other aspect of a virtual application is that it also participates in process management. IIS/WAS has the concept of application pools. An application pool is a definition or template of a worker process (w3wp.exe) that is used by IIS/WAS to create new worker process instances. Two most important properties of an application pool are:

It has an identity which is the running account of the worker process in this pool. You can configure the identity to a specific account so that you can achieve security isolation from other pools.
It has a list of settings to control the health of worker processes running in this pool. For example, you can set process recycling and idle timeout, enable debugging, configure Web Gardens, or enable Rapid-Fail Protection (RFP), etc. For IIS6, more information can be found athttp://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/c9b5db6f-874e-4ec9-93ed-1733367c117b.mspx?mfr=true.

Each virtual application must be assigned to an application pool in IIS. All of the requests (except for static content) will be handled in worker processes in that application pool.

Please note that Application Pool is managed by WAS instead of IIS in the IIS7 family. This separation makes non-HTTP activation possible. With this refactoring, “IIS” is simply the web server that only handles HTTP/HTTPS requests.

ASP.NET Application

For ASP.NET, a virtual application has its real meaning as an “application”. When an ASP.NET request is first received in a virtual application, a new AppDomain is created in the worker process that handles subsequent ASP.NET requests. This includes all WCF requests. So in the ASP.NET world, a virtual application is mapped to an AppDomain. This provides important code isolation for managed applications that sits in the same worker process. It is even more important for web hosting when the applications are running in the partial trust environment.

Virtual Directory

Isn’t “virtual directory” the same as “virtual application”? In IIS6, from the IIS Manager (UI), if you right click on “Default Web Site” -> New, you will see “Virtual Directory …” from the list. What is going on there? Well, as I said, the terms are misused in IIS6. When it says “Virtual Directory”, it actually means “Virtual Application”.

Am I kidding? No. A real “virtual directory” is just a container of files. It is a construction unit of a virtual application, just like a virtual application to a web site. A virtual application must have at least one virtual directory. Here is a sample configuration section that defines the virtual application “/foo” and its virtual directories in the WAS' configuration file %windir%\system32\inetsrv\config\applicationhost.config:

<sites>

application>

...

site>

sites>

Note that the virtual directory “/bar” points to a different physical path, actually it points to a network share (UNC) path!

How can we create a real virtual directory in IIS6 then? It is a little bit trickier from the UI. In the IIS Manager UI, you can right click on the virtual application and then click on New -> “Virtual Directory …”. After specifying the alias and path, you will get the virtual directory using all default settings.

However, there is another trick to convert a virtual application into a virtual directory. Here are the steps:

Create a virtual application “/foo” and a sub virtual application “/foo/bar”.
Right click on the virtual application “/foo/bar” and select properties. You will see the properties dialog popped up.
Under the “Virtual Directory” tab, look for the “Remove” button. See the image below:

Click the “Remove” button and click on “OK” button.

Now you have created a virtual directory “/bar” under the virtual application “/foo”. The icon for the virtual application is different than that of the virtual application. Here is what you will see:

Nesting

Virtual applications and virtual directories can be nested, meaning, a virtual application or directory can be created under another virtual application or directory in any combinations.

This nesting has the following implications:

The virtual path of the parent application/directory is the prefix of the child application/directory.
For ASP.NET, the web.config of the parent virtual application/directory affects the child application/directory.
For ASP.NET, the assemblies referenced by the parent virtual application are inherited by the children.

Other than those, virtual applications still have their own isolation that I mentioned in the above sections.

IIS7/WAS Installation

2008-11-28T00:34:00.000-08:00

IIS7 has a modular design which allows you to selectively install components that are needed. This design is based on the new manifest-driven Componentization technology that was first introduced in Windows Vista. As the IIS site claimed, there are more than 40 standalone feature components of IIS7 which can be independently installed. This is good or bad. The good part is that IT professionals can easily customize the installation as needed. The bad part is that it’s hard for developers to understand which components are needed. Here I would like to write something regarding the latter.

If you are familiar with CMI (Component Management Interface) or CBS (Component Based Setup), you would know that there are many different ways to install components on Vista. You can use the GUI interface (called Software Explorer) which is available from “Control Panel” -> Programs -> “Turn Windows features on or off”. Or you can use command-line tools such as pkgmgr.exe or ocsetup.exe (which is a wrapper of pkgmgr.exe). I will talk about the simplest approach, GUI interface, below.

Minimal Installation: Installing WAS

The minimal installation of the whole IIS7 package is to install the Windows Process Activation Service (WAS). WAS is a standalone feature and it is the only feature from the IIS7 family that is available for all Windows Vista client SKUs (Basic, Home, Business, and Ultimate, etc).

From the “Turn Windows features on or off” UI of the control panel, you will see the WAS component listed in the list as in the following image:

This feature has three sub-components:

.NET Environment
Configuration APIs
Process Model

If you select the root node of WAS, only the “Process Model” sub-node is checked to be installed by default with the root. Please note that with this installation, you still cannot do anything interesting today. It only means that you can get WAS to work.

If you further check the “Internet Information Services” feature from the feature list, you will find out that the “Configuration APIs’ node is automatically checked.

In order to make WCF or any ASP.NET application to work, you need to further check the sub-node “.NET Environment”. This means that all of WAS components are needed in order to make WCF/ASP.NET to work well. Fortunately these are automatically checked once you install any of those components.

IIS7: Default Installation

By simply checking the “Internet Information Services” feature from the UI, you will see that quite some sub-nodes are automatically marked as following:

This is the default installation of IIS7. In this way, you can use IIS7 to service static content (such as HTML pages etc). However, you can’t run ASP.NET or CGI applications.

IIS7: Installlation with ASP.NET support

From the above image, it’s obvious that you need to install “ASP.NET” to make ASP.NET work on IIS7. After checking “ASP.NET”, you will find the following UI:

This is the minimal environment for both WCF and ASP.NET applications to work in IIS7.

Installation with IIS6 Compatibility Components

Many people still have problems with the above installation when they run Visual Studio 2005 or some automation scripts/tools (for example, adsutil.vbs) to configure virtual applications. The main reason is because those tools depend on the legacy IIS6 Metabase API support as well as the legacy IIS6 scripting tools. Here is the UI that shows what are missing from above:

You need to check “IIS 6 Scripting Tools” (which automatically checks other three subnodes of “IIS 6 Management Compatibility”). After that, you will see the following UI:

With this installation, you are good to play with IIS7, ASP.NET, and WCF features and samples available on the web.

Maximum Installation

You may want to play with other components that are not installed by default. To install them, you can simply go through the whole tree of the IIS and check every leaf node. In this way, you will get the full IIS7 feature set installed.

Impersonation with Double Identities

2008-11-28T00:32:00.002-08:00

There are two different levels of security that you can use for WCF services: Message level and Transport level. For Transport level, in HTTP case, you can use different IIS Authentication mechanisms to perform client authentication. If you do not carefully set the settings of the WCF binding, you may end up with both security levels enabled. This has a direct impact of impersonation. The reason is because WCF does not know which identity you want to apply to impersonation.

Generally, it is not recommended to have double securities enabled. However, there is actually a reason why people could get into this dilemma:

It is normal for people to disable anonymous access in IIS. In WCF, we want to make sure that a service explicitly specifies its transport level security settings. In this case, it means that you have to configure the service to not use anonymous authentication at transport layer. So when you also want to enable message-level security to perform message signing or encryption, you would get into this double-identity situation.

Here is a simple custom binding configuration that demonstrates how it is the case of double identities:

binding>

customBinding>

It enables both message-level security and it also enables the NTLM authentication at the transport layer.

In this case, if you have an operation which requires impersonation, you would get the following error on the server side (you can see it from a debugger):

System.InvalidOperationException: Cannot start impersonation because the SecurityContext for the UltimateReceiver role from the request message with the 'http://www.microsoft.com/test/IHelloContract/Hello' action is not mapped to a Windows identity.

This is because WCF actually set the ServiceSecurityContext to WindowsIdentity.Anonymous when multiple identifies are found.

There are three different ways to resolve this issue.

1. Enable Anonymous Access from IIS

This is the simplest way, though there is a security concern for this approach. Here is the binding configuration that does not have the transport-layer authentication enabled:

binding>

customBinding>

You have to enable the anonymous access in IIS to make this work, otherwise you would get ServiceActivationException on the server side due to mismatched settings between WCF binding and IIS.

This is not the ideal solution if you have other services in the same application that you want to have anonymous access disabled for security purpose.

2. Use Imperative Impersonation

When I said impersonation would fail above, I meant declarative (or automatic) impersonation. Here is the sample service operation that does this:

[OperationBehavior(Impersonation =ImpersonationOption.Required)]

public string Hello(string greeting)

To use imperative impersonation, you need to remove the “Impersonation” setting from the above declaration and perform impersonation from code. This requires having a Windows identity being retrieved from the context. Fortunately WCF provides a way for you to find the identities that are available in the stack:

OperationContext.Current.ServiceSecurityContext.AuthorizationContext.Properties["Identities"]

You can cast this into List and examine each identity of them. You cannot tell which identity is from which layer though. However, in WCF V1, the identity from the transport layer is always the first one. But this is guaranteed in future versions.

Once you have the Windows identity, you can perform the impersonation by yourself:

using (identity.Impersonate())

{

// Do something

}

3. Remove Unnecessary Identities Using Custom Authorization Policy

If you are still not satisfied by the above approaches, here is another choice for you. You need to use the ServiceAuthorizationBehavior.ExternalAuthorizationPolicies extension point to add an extra authorization policy to remove identities which are not needed. Here is a good sample about how to implement a custom authorization policy: http://msdn2.microsoft.com/en-gb/library/aa702720.aspx.

In our case, we can implement the Evaluate() method of the custom MyAuthorizationPolicy as following so that the last identity is picked:

public bool Evaluate(EvaluationContext evaluationContext, refobject state)

{

IList<IIdentity> identities = evaluationContext.Properties["Identities"] as IList<IIdentity>;

if (identities != null && identities.Count > 1)

{

// Pick the last one (which is likely to be the identity embeded in the message.

evaluationContext.Properties["Identities"] =

new List<IIdentity>(new IIdentity[] { identities[identities.Count - 1] });

}

return true;

}

Now you can configure the Authorization behavior in your ServiceHost. You need to implement ServiceHostFactory so that this custom behavior can be added to the ServiceHost. Here is an implementation of the CreateServiceHost method:

public override ServiceHostBase CreateServiceHost(stringconstructorString, Uri[] baseAddresses)

{

ServiceHost serviceHost = newServiceHost(typeof(HelloService), baseAddresses);

serviceHost.Authorization.ExternalAuthorizationPolicies =new ReadOnlyCollection<IAuthorizationPolicy>(

new IAuthorizationPolicy[] {

new MyAuthorizationPolicy()

});

return serviceHost;

}

The sample code for this blog entry is attached.

How to change HostName in WSDL for an IIS-hosted service?

2008-11-28T00:32:00.001-08:00

If you have a web-hosted service “simple.svc” under the virtual application “/simple”, you would probably get the following service address in the WSDL:

<wsdl:service name="SimpleService">

<wsdl:port name="BasicHttpBinding_ISimpleContract"binding="tns:BasicHttpBinding_ISimpleContract">

<soap:address location="http://mycomputer.private.mydomain.com/simple/Simple.svc" />

wsdl:port>

wsdl:service>

The host name “mycomputer.private.mydomain.com” is automatically picked up by WCF. In the real production environment, you would want to use a public host name or even an IP address in the address. Here are a few steps that can help you to make the change:

1) Change IIS Site Binding

WCF populates service base addresses based on IIS site bindings. The format of a site binding looks like “::”. For HTTP, the default site binding for the default web site is “:80:”. This means that the service can receive messages from any IP addresses for the host and it uses “weak” wildcard for address registration. You need to change it to be an “exact” host name for the site so that it shows up in your service base address. You can use the IIS utility tool adsutil.vbs (or appcmd.exe on IIS7) to achieve that.

You can query your current site bindings for the default web site as following:

cscript //nologo %systemdrive%\inetpub\adminscripts\adsutil.vbs get W3SVC/1/ServerBindings

Here is the command to change it:

cscript //nologo %systemdrive%\inetpub\adminscripts\adsutil.vbs set W3SVC/1/ServerBindings “:80:www.fancydomain.com”

You can also change it from IIS Manager UI. For HTTPS, the following command would work:

cscript //nologo %systemdrive%\inetpub\adminscripts\adsutil.vbs set W3SVC/1/SecureBindings“:443:www.fancydomain.com”

2) Recycle the AppDomain

Once you changed IIS settings, WCF does not automatically pick up the changes from IIS Metabase. You have to recycle the current AppDomain for the virtual application. There are a few different ways to do that:

· Change web.config file for the virtual application

· Kill w3wp.exe process

· Run “iisreset.exe”

3) Query the WSDL

Now when you query the WSDL of your service, you will see the new addresses:

<wsdl:service name="SimpleService">

<wsdl:port name="BasicHttpBinding_ISimpleContract"binding="tns:BasicHttpBinding_ISimpleContract">

<soap:address location="http://www.fancydomain.com /simple/Simple.svc" />

wsdl:port>

wsdl:service>

How to use .asmx extension to handle WCF requests?

2008-11-28T00:32:00.000-08:00

For backward compatibility, WCF supports easy server-side migration from ASMX to WCF. This is good news for existing ASMX customers. Generally, the clients of ASMX may have server Urls hard-coded with the extension “.asmx”. For example, here is a sample Url:

http://www.myserver.com/foo/MyService.asmx

After installing WCF on the box, you can let WCF to handle the same client requests. Here are the steps about how to achieve this:

Replace BuildProvider for ASMX

You need to use the WCF service build provider for .asmx extension by seting the following in the web.config file of your virtual application:

<system.web>

buildProviders>

compilation>

system.web>

When WCF is running in the Mixed Transport mode (instead of AspNetCompatibility mode), WCF would intercept the request based on the BuildProvider information for the extension.

Replace HttpHandler for ASMX

If you are running WCF in AspNetCompatibility mode, you would also need to change the HttpHandler s for .asmx to the WCF HttpHandler. On IIS6, you just need to have something as following in your config:

<system.web>

<remove path="*.asmx" verb="*">remove>

<add path="*.asmx" verb="*" type="System.ServiceModel.Activation.HttpHandler, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"

validate="false" />

httpHandlers>

system.web>

On IIS7, things are different. IIS7 introduces two different HTTP pipelines: Integrated and Classic. The latter works similar as IIS6 in the way that all of the managed requests go through the ASP.NET ISAPI filter. When this happens, the HttpModules and HttpHandlers defined in web.config files would be invoked for the corresponding requests.

When the virtual application is running in the Integrated mode, however, the modules and handlers defined in web.config files under the section are totally ignored. All of the requests are handled straightforward by IIS7. So you need to make sure that you have integrated handlers defined for the corresponding extensions. We can set the following in the web.config of the virtual application to achieve this:

<system.webServer>

handlers>

system.webServer>

The section is actually rooted in %windir%\system32\inetsrv\config\applicationhost.config instead of in the root web.config in %windir%\Microsoft.Net\Framework{64}\v2.0.50727\config. The element takes the “name” as the key instead of the “path” as we did to the section. You must specify “validateIntegratedModeConfiguration” to false to make IIS happy.

Correct SOAP Actions

Once you configured above settings, you can create a .asmx file which looks exactly as a .svc file. For example, you can have the following content:

<% @ServiceHost language = "c#" Factory="HelloWorld.SimpleServiceHostFactory" %>

Now you can browse your service with an .asmx extension. At this point, all requests will go through happily into WCF channel stack.

One last thing that you need to be aware is that you need to make sure your WCF service is backward compatible to ASMX so that ASMX clients can communicate with it. Basically you need to use the interoperable binding such as BasicHttpBinding. And you need to make sure the request/response SOAP actions are expected for ASMX clients. Here is an example:

[ServiceContract(Name = "RequestReplyService", Namespace ="http://myoldasmxworld.org/")]

public interface IRequestReplySyncServiceAsmx

{

[OperationContract(IsOneWay = false, Action ="http://myoldasmxworld.org/HelloRequestReply")]

string HelloRequestReply(string text);

}

It is compatible to the following ASMX web service:

[WebService(Name = "MyAsmxService", Namespace ="http://myoldasmxworld.org/")]

public class AsmxRequestReplyService

{

[WebMethod]

public string HelloRequestReply(string text)

{

// Implementation

}

How to redirect a Url in IIS6/IIS7 and in ASP.NET?

2008-11-28T00:31:00.000-08:00

Sometimes you want to redirect users request to a different one when you want to retire old ones but still provide backward-compatibility. David Wang has a good summary on different redirects for IIS in his blog entry. Here I just want to add a few points which have helped people to resolve tricky problems.

First of all, as David pointed out, there are two (or three in David’s terms) types of redirects:

· Client-side redirection: the server sends a “302 Redirect” response to the client together with the new location header.

· Server-side redirection: the server rewrites the request with another URL transparently and the client is not aware of anything.

Client-side redirection

It is also called HTTP redirection. You can achieve it in the following ways.

Redirect in IIS6

You can use the HttpRedirect Metabase setting to perform redirection in IIS6. This property can be set to a virtual application, a file, or a virtual directory (a.k.a. web folder). It requires the physical existence of these “source” items. To achieve that, you can use IIS Manager. Here are the steps on how to set it for a file:

· Right click on the file and click on Properties

· Click on “File” tab of the dialog

· Select “A redirection to a URL” radio box

· Type in your new Url, and/or make any other changes, and click OK.

After this, you would have setup the file so that all requests to this file is redirected to the new Url. You can check the Metabase setting with the following command:

cscript.exe %SystemDrive%\Inetpub\AdminScripts\adsutil.vbs get /w3svc/1/Root/foo/p1.aspx/HttpRedirect

If the file does not have any Metabase property pre-defined in the Metabase, you cannot use adsutil.vbs to set this property. But you can set it with the script to a virtual application.

Redirect in IIS7

In IIS7, the concept is similar as that of IIS6. You can use the new command “appcmd.exe” to enable redirection as following:

%windir%\system32\inetsrv\appcmd set config "Default Web Site/foo" -section:system.webServer/httpRedirect -enabled:true -destination:"http://localhost/bar/p1.aspx"

This tells IIS to redirect all request sending to the virtual application “/foo” to “/bar/p1.aspx”. The actual result is that appcmd.exe adds the following section to the web.config file for the application “/foo”:

<system.webServer>

system.webServer>

Redirect with ASP.NET

You can also use ASP.NET to implement client-side redirection. If you don’t want ASP.NET pipeline to intercept any such request, you would need to implement the logic in the global.asax file. This is important for WCF applications since WCF intercepts requests from the pipeline for WCF requests. Here is some sample code for a global.asax file:

<%@ Application Language="C#" Debug="true" %>

This approach is more flexible than those provided by IIS:

· It does not require the existence of the physical file.

· It is imperative and thus you can add any custom programming logic to determine whether you want to redirect the request. For example, you can check the query string to see whether it contains the information that requires a redirection.

Server-side redirection

It is sometimes also called Url rewriting or Url aliasing. One of the advantages for server-side redirection is performance because there is no round-trip involved if the redirection is on the same machine.

Redirect with ASP.NET

You can use ASP.NET to implement the server-side redirection with Server.Transfer(path) method.

Kaushik Rabadiya

8 simple SEO tips for blogs

Instantiating components on template markup

Imperative code blocks

Unobtrusive and imperative

Fully declarative

Conclusion

ASP.NET MVC on IIS 6 Walkthrough

Initial Setup

Using a URL File Extensions

Mapping .mvc to ASP.NET

Specifying Routes with an Extension

Uh oh, Houston! We have a problem

IIS6 Extension-less URLs

Final Tips

Did you know… How to add a Linked Item to a project

Tracking User Activity

Introduction

A Look at the Membership System's User Tracking Implementation

Designing the User Activity Log Database Table

Figure 1: The ActivityLog table models the activity log.

Logging User Activity

Displaying a Particular User's Activity History

Figure 2: Scott's activity history is displayed in a grid.

Viewing the Online Users and their Last Performed Activity

Figure 3: Those users currently online are listed along with their most recent activity.

Conclusion

References

Nokia N79

Device Description:

Technical Specs

General

Extra Features

APIs

Browser & Flash

Multimedia

Memory Functions

Connectivity

Messaging

Power Management

Other

Tools

Recommended SDK(s)

Hosting an “Indigo” (WCF) Service

Introduction

Hosting Environments

ASMX Services

WCF Services

Different Hosting Environments

WAS Hosting Environment

A Simple Hosted Service

Service Configuration

Service Addressing

Service Activation

Service Recycling

ASP.NET Async Pages vs Async WCF Service Operation

Cannot Find Server (404) or Get Plain Text for WCF .svc Files From IIS?

Question

Why?

Solutions

How to use WSDualHttpBinding on Windows XP for Hosted Services

WinFX February CTP is released!

What is IIS7?

Virtual Application vs Virtual Directory

Virtual Application

What is it?

Protocol Listening

Application Pool

ASP.NET Application

Virtual Directory

Nesting

IIS7/WAS Installation

Minimal Installation: Installing WAS

IIS7: Default Installation

IIS7: Installlation with ASP.NET support

Installation with IIS6 Compatibility Components

Maximum Installation

Impersonation with Double Identities

How to change HostName in WSDL for an IIS-hosted service?

How to use .asmx extension to handle WCF requests?