Michael's Coding Den: Web

ASP.NET Theme across all pages with XMLHttpRequest calls

Sun, 27 Jul 2008 14:42:19 GMT

ASP.NET Themes is very powerful feature, but some limitations exist when you are trying to apply Themes dynamically.

For the single page the way to apply theme is to use

Page.Theme = “<themeName>”;

inside the OnPreInit event, but if you try to apply theme for all pages across your site you have two solutions:

add this code to each of the pages
apply theme for master.page – and it’s where problem starts

ASP.NET master pages don’t support applying themes dynamically – only static support for the all site pages by setting attribute inside web.config.

But what to do if you need control which theme to apply and you don’t want to add code to every page of your site?!

The solution for this to create custom HttpModule, where apply theme for Page class inside PreRequestHandlerExecute event.

See the following code-snippet of the ThemeHttpModule

   1: public void Init(HttpApplication context)   2: {   3:     context.PreRequestHandlerExecute += context_PreRequestHandlerExecute;   4: }   5:     6: void context_PreRequestHandlerExecute(object sender, EventArgs e)   7: {   8:     HttpContext context = HttpContext.Current;   9:     if (!(context.Handler is Page))  10:     {  11:         return;  12:     }  13:    14:     Page page = (Page)context.Handler;  15:       16:     if ((page != null))  17:     {  18:         string themeName = "Default";  // get theme name from somewhere  19:         page.Theme = themeName;  20:     }  21: }

Done. Now you have flexible control which theme to apply in realtime, extracting you theme names from config or from database.

But there is one case, I’d like point you attention – XMLHttpRequest calls.

If you have AJAX XMLHttpRequest direct calls - this code won’t work, because server returns you only portion of page, not the full page with header and body. And you can’t apply theme on partial pages.

To solve this you need to check if it’s partial request or not, inside your HttpModule. In case of ASP.NET AJAX you could use ScriptManager.IsInAsyncPostBack, but for the direct XMLHttpRequest calls you need to check the header for the Content-Type you are used when create the MSXML object.

Something like this

   1: // Don't apply theme for XMLHttpRequest calls, because you are getting part of the page, not the full page   2: if (! string.IsNullOrEmpty(context.Request.ContentType))   3: {   4:     return;   5: }

Now your themes will be applied only on pages, not the partial AJAX calls.

Mirror: ASP.NET Theme across all pages with XMLHttpRequest calls

Attend ReMIX 08 in Sydney - Experts stand

Thu, 08 May 2008 10:41:32 GMT

Going to attend the ReMIX 08 in Sydney. You can catch me in "Expert Stand" section during breaks.

Mirror: Attend ReMIX 08 in Sydney - Experts stand

"Please wait..." online control generation

Thu, 29 Nov 2007 13:27:14 GMT

Recently I was looking for the different controls to represent "wait" indicator on the web page, and found the great site http://ajaxload.info/ , which allows you to generate number of different wait controls. You can view them online and download to use on your site.

Updated: another collection is there http://www.napyfab.com/ajax-indicators/

Mirror: Please wait... online control generation

Overview of all Web Services standards

Mon, 02 Jul 2007 03:56:05 GMT

Michele Leroux Bustamante published a really good description of WS-* standards.

If you had some problems in understanding why and where this formats are for - now it's not the problem, because this topic was examined in details

ASP.NET AJAX Extensions Intro with samples

Sat, 05 May 2007 17:53:29 GMT

Just found awesome description of ASP.NET AJAX Extension with good samples.

Read there http://www.simple-talk.com/dotnet/asp.net/enhance-your-website-with-asp.net-ajax-extensions/

ASP.NET 2.0 tutorials, howtos, labs.

Fri, 03 Nov 2006 15:27:21 GMT

Great link that comprises numbers of tutorials, howtos, and labs related to ASP.NET 2.0 and AJAX.

And there is the "JavaScript with ASP.NET 2.0 Pages" article about he new features of JS support

Creating Ultimate Mashup

Tue, 12 Sep 2006 13:46:20 GMT

This series chronicles the creation of the ultimate mashup.

Intro - Mashups: The new breed of Web app

Part 1 - Learn the concept of mashups, see how they work, and build a simple version of one.

Part 2 - Manage a mashup data cache.

Part 3 - Understand RDF

Part 4 - Creating an ontology

Part 5 - Change out Web services

Part 6 - Give the user control (final)

XQuery - Power your mashups with XQuery

All parts are available in PDF format.

Async calls in ASP.NET

Wed, 05 Apr 2006 18:33:10 GMT

Good example of applying async calls for ASP.NET: http://www.codeproject.com/cs/webservices/asyncws.asp

and another approach using XMLHTTPRequest with Russian translation

Additional articles:

- http://www.eggheadcafe.com/articles/20060620.asp

- http://www.realcoding.net/article/view/3670 (rus)

What's the Web 2.0

Sat, 04 Mar 2006 12:30:59 GMT

Excellent description of main Web 2.0 features

Services, not packaged software, with cost-effective scalability
Control over unique, hard-to-recreate data sources that get richer as more people use them
Trusting users as co-developers
Harnessing collective intelligence
Leveraging the long tail through customer self-service
Software above the level of a single device
Lightweight user interfaces, development models, AND business models

AJAX Learning Guide

Fri, 10 Feb 2006 13:50:55 GMT

AJAX Learning Guide is over there and here: principles, architecture model, tutorials and samples

The SQL Site Map Provider we've been waiting for

Mon, 06 Feb 2006 04:37:23 GMT

Jeff Prosise published his final SQL Site Map Provider. Now we can store our site map structure in database, instead of using XML.

Several related topics:

sample of using MasterPages: http://weblogs.asp.net/scottgu/archive/2006/01/17/435765.aspx
site navigation features: http://weblogs.asp.net/scottgu/archive/2005/11/20/431019.aspx
building your own Data Source Controls: http://weblogs.asp.net/scottgu/archive/2005/12/04/432319.aspx

ASP.NET tips

Tue, 30 Aug 2005 10:46:42 GMT

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