Regan Schroder

Trading Center my advancing of the Classifieds Starter Kit

Spider Master — Fri, 15 Jan 2010 16:58:00 GMT

A few years ago I needed to work on a project that enabled online auctions in real time that brought back the true auction experience but through the web browser and a downloadable forms application.

Now with this application being prepared for release we have decided to give back to the community and have started to further develop the kit.

I would like to here your comments and suggestions and anyone is welcome to download Trading Center on codeplex or have a play Trading Center Live Online Demo.

Yes this post is short how ever please follow the above links for more detail.

Happy Trading.

Regards Regan

Asp.Net Classifieds Starter Kit Does Not Run in IIS7

Spider Master — Fri, 25 Jul 2008 06:15:00 GMT

As many have found that it has become a headache when deploying the classifieds (starter kit) application to IIS7 with all the changes made to the new operating system, Below you will find the old code and the new code to better help you understand and modify your code accordingly. If your site is a fresh down load or you have not modified the required files for this fix then you can simply copy and paste into Visual Studio or Visual Web Developer

The Error that we are thrown is "System.Web.HttpException: Request is not available in this context"

Below is the code to correct this issue/error. More information can be found here on an early blog about this actual error and what it means and again why we got the error in the first place when things work fine in previous versions of IIS (Internet Information Services)

App_Code/Web/ClassifiedsHttpApplication.cs

using System;

using System.Web;

using System.Threading;

using AspNet.StarterKits.Classifieds.BusinessLogicLayer;

namespace AspNet.StarterKits.Classifieds.Web

{

public class ClassifiedsHttpApplication : HttpApplication

{

private static object _settingsLock = new object();
private static object _notificationLock = new object();
private static SiteSettings _settings;
private static DateTime _lastNotificationTime;
private static string _siteUrl; private static Timer _hourlyTimer;
public class FirstRequestInitialization // Runs once only on startup and reboot.

{

private static bool s_InitializedAlready = false;
private static Object s_lock = new Object();
// Initialize only on the first request
public static void Initialize(HttpContext context)
{

if (s_InitializedAlready)
{

return;

}
lock (s_lock)
{

if (s_InitializedAlready)

{

return;

}

_siteUrl = GetSiteUrl(context);

// set-up Settings
ClassifiedsHttpApplication.ClassifiedsApplicationSettings = SiteSettings.LoadFromConfiguration();
// set-up maintenance timer
_lastNotificationTime = DateTime.Now;
TimerCallback callback = new TimerCallback(Maintenance.HourlyMaintenanceTimer);
_hourlyTimer = new Timer(callback, null, TimeSpan.Zero, TimeSpan.FromHours(1.0));
// Save //
s_InitializedAlready = true;

}

}
void Application_BeginRequest(Object source, EventArgs e)
{

HttpApplication app = (HttpApplication)source;

HttpContext context = app.Context;

// Attempt to peform first request initialization
FirstRequestInitialization.Initialize(context);

}

}
public static SiteSettings ClassifiedsApplicationSettings
{

get

{

if (_settings == null)
ClassifiedsApplicationSettings = SiteSettings.LoadFromConfiguration();
return _settings;

}

set

{

if (value == null)
throw new ArgumentNullException("ClassifiedsApplicationSettings cannot be set to null");
lock (_settingsLock)
{

_settings = value;

}

}

}

public static DateTime LastNotificationSent
{

get

{

return _lastNotificationTime;
}

set

{

lock (_notificationLock)
{

_lastNotificationTime = value;

}

}

}
public static string SiteUrl
{

get

{

return _siteUrl;

}

}
private static string GetSiteUrl(HttpContext context)
{

string baseUrl = null;

if (context != null)

{

string port = context.Request.ServerVariables["SERVER_PORT"];

if (port == null || port.Equals("80") || port.Equals("443"))

port = String.Empty;

else

port = ":" + port;

string protocol = context.Request.ServerVariables["SERVER_PORT_SECURE"];

if (protocol == null || protocol.Equals("0"))

protocol = "http://";

else

protocol = "https://";

baseUrl = protocol + context.Request.ServerVariables["SERVER_NAME"] + port + context.Request.ApplicationPath;

}
return baseUrl;

}
void Application_End(Object sender, EventArgs e)
{

}
void Application_Error(Object sender, EventArgs e)
{

}

}

}

Global.ascx

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

<%@ Import Namespace="AspNet.StarterKits.Classifieds.Web" %>

void Application_Start(object sender, EventArgs e)

{

// Code that runs on application startup
if (!Roles.RoleExists("Administrators")) Roles.CreateRole("Administrators");if (!Roles.RoleExists("Guests")) Roles.CreateRole("Guests");

}

void Application_BeginRequest(Object source, EventArgs e)

{

// Code that runs on Application startup but only runs once - Will run again on ReBoot.
HttpApplication app = (HttpApplication)source; HttpContext context = app.Context;
// Attempt to peform first request initialization
ClassifiedsHttpApplication.FirstRequestInitialization.Initialize(context);

}

</script>

Recieved by X-Post from = http://www.spidermaster.org/blogs/spidermaster

IIS7 Integrated mode: Request is not available in this context exception in Application_Start

Spider Master — Fri, 25 Jul 2008 05:26:00 GMT

The “Request is not available in this context” exception is one of the more common errors you may receive on when moving ASP.NET applications to Integrated mode on IIS 7.0. This exception happens in your implementation of the Application_Start method in the global.asax file if you attempt to access the HttpContext of the request that started the application. It looks something like this:

Server Error in '/' Application.

Request is not available in this context

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: Request is not available in this context

Source Error:

Line 3:  {
Line 4:      HttpContext context = HttpContext.Current;
Line 5:      String appPath = context.Request.ApplicationPath;
Line 6:  }
Line 7:  </script>

Source File: c:\inetpub\wwwroot\global.asax Line: 5

Stack Trace:

[HttpException (0x80004005): Request is not available in this context]
   System.Web.HttpContext.get_Request() +3467061
   ASP.global_asax.Application_Start(Object source, EventArgs e) in c:\inetpub\wwwroot\global.asax:5

[HttpException (0x80004005): Request is not available in this context]
   System.Web.HttpApplicationFactory.EnsureAppStartCalledForIntegratedMode(HttpContext context, HttpApplication app) +3388766
   …

This error is due to a design change in the IIS7 Integrated pipeline that makes the request context unavailable in Application_Start event. When using the Classic mode (the only mode when running on previous versions of IIS), the request context used to be available, even though the Application_Start event has always been intended as a global and request-agnostic event in the application lifetime. Despite this, because ASP.NET applications were always started by the first request to the app, it used to be possible to get to the request context through the static HttpContext.Current field.

Applications have taken a dependency on this behavior become broken in Integrated mode, which officially decouples Application_Start from the request that starts the application. In the future, we may introduce changes that will further break the assumption that applications start because of requests – for example, by introducing a warmup mechanism that can start ASP.NET applications based on a specific schedule.

So, what does this mean to you?

Basically, if you happen to be accessing the request context in Application_Start, you have two choices:

Change your application code to not use the request context (recommended).
Move the application to Classic mode (NOT recommended).

In fact, most of the customers I have spoken to realize that they do not need to access the request context in Application_Start. Because this event is intended for global initialization activities, any logic that references a specific request is typically a design oversight.

In these cases, it should be trivial to remove any reference to HttpContext.Current from the Application_Start method.

A common example of this is using the HttpContext.Current.Request.ApplicationPath to get to the application’s root virtual path. This should become HttpRuntime.AppDomainAppVirtualPath. Voila, no need to use the request!

In the cases where you do need to access the request information for the first request to the application (I have seen VERY few applications where this is the case), you can use a workaround that moves your first-request initialization from Application_Start to BeginRequest and performs the request-specific initialization on the first request.

Here is an example of how to do that in your global.asax (you can also do it in a module):

void Application_BeginRequest(Object source, EventArgs e)

{

HttpApplication app = (HttpApplication)source;
HttpContext context = app.Context;

// Attempt to peform first request initialization
FirstRequestInitialization.Initialize(context);

}

class FirstRequestInitialization

{

private static bool s_InitializedAlready = false;
private static Object s_lock = new Object();

// Initialize only on the first request
public static void Initialize(HttpContext context)
{

if (s_InitializedAlready)
{

return;

}
lock (s_lock)
{

if (s_InitializedAlready)

{

return;

}

// Perform first-request initialization here ...
s_InitializedAlready = true;
}

}

}

This code attempts to initialize at the beginning of each request, with only the first request performing the initialization (hence, first request initialization J). Note that the lock is necessary to insure correct behavior in the case where multiple requests arrive to your application near simultaneously (don’t lock around type objects, since this may lock multiple appdomains – see Rico’s post).

With this issue out of the way, you should be able to enjoy the benefits of Integrated mode on IIS7 without much other grief. For more info on ASP.NET Integrated mode and how to take advantage of it, be sure to check out http://www.iis.net/articles/view.aspx/IIS7/Extending-IIS7/Getting-Started/How-to-Take-Advantage-of-the-IIS7-Integrated-Pipel.

Thanks,

Recieved by X-Post from = http://www.spidermaster.org/blogs/spidermaster

Original Source from = http://mvolo.com/blogs/serverside/archive/2007/11/10/Integrated-mode-Request-is-not-available-in-this-context-in-Application_5F00_Start.aspx

Remove border-width:0px from asp:Image or asp:ImageButton

Spider Master — Mon, 21 Jan 2008 18:02:00 GMT

First off hello all and here is my first code post and bug fix

This in fact is a **bug** even if intentional when developing the <asp:Image /> and also the <asp:ImageButton /> tags

The issue that has been brought up in many forums recently and discussions are popping up all over the place regarding the asp image control and now also the image button has the same issue.

Let me explain. Have you ever run through your HTML source view in your browser to check on how things are being compiled and distributed to the browser in HTML. If you run a standard asp:image tag you will find it has given itself a style attribute border-width:0px

Now this is ok unless you wanted to apply a cssClass or used an attached css to give the image another border. When the clash comes about you can end up with no styling and in some cases no image.

There is a way around this.

1. Use an <img> tag instead.

2. Create your own image control over-ride (class)

Now this is not something you need to reference anywhere else and it will in fact make every <asp:image> return with no border style attributes.

C# Code - For the Pros

Borderless Image Class

using System;

using System.Web.UI.WebControls;

public class BorderlessImage : Image

{

public override Unit BorderWidth
{

get

{

if (base.BorderWidth.IsEmpty)

return Unit.Pixel(0);

else

return base.BorderWidth;

}

set

{

base.BorderWidth = value;

}

}

}

Borderless Image Button Class

using System;

using System.Web.UI.WebControls;

public class BorderlessImageButton : ImageButton

{

public override Unit BorderWidth

{

get

{

if (base.BorderWidth.IsEmpty)

return Unit.Pixel(0);

else

return base.BorderWidth;

}

set

{

base.BorderWidth = value;

}

}

VB Code - For Rookies

Borderless Image Class

Imports Microsoft.VisualBasic

Public Class BorderlessImage

Inherits System.Web.UI.WebControls.Image
Public Overrides Property BorderWidth() As System.Web.UI.WebControls.Unit

Get

If MyBase.BorderWidth.IsEmpty Then

Return Unit.Pixel(0)

Else : Return

MyBase.BorderWidth()

End If
End Get
Set(ByVal value As System.Web.UI.WebControls.Unit)

MyBase.BorderWidth = value
End Set

End Property

End Class

Borderless Image Button Class

Imports Microsoft.VisualBasic

Public Class BorderlessImageButton

Inherits System.Web.UI.WebControls.ImageButton
Public Overrides Property BorderWidth() As System.Web.UI.WebControls.Unit

Get

If MyBase.BorderWidth.IsEmpty Then

Return Unit.Pixel(0)

Else : Return

MyBase.BorderWidth()

End If
End Get
Set(ByVal value As System.Web.UI.WebControls.Unit)

MyBase.BorderWidth = value
End Set

End Property

End Class

Ad tag refrencess to web config- If not added then your code is useless (you can do this in page also)

<system.web>

<pages>
<tagMapping>
<add tagType="System.Web.UI.WebControls.Image" mappedTagType="BorderlessImage"/>

<add tagType="System.Web.UI.WebControls.ImageButton" mappedTagType="BorderlessImageButton"/>

</tagMapping>
</pages>

</system.web>

......

Recieved by X-Post from = http://www.spidermaster.org/blogs/spidermaster