Implementing UpdatePanel manually - c#

I was reading an article that shows how bad CodePlex uses UpdatePanels and how nice is StackOverflow on this matter when, for example, a user upvotes an answer/question.
I wonder if someone can point a tutorial on how to do such action.
I know some points:
Create a Web Service that gets the action value and ouputs a JSON string
Build the javascript inside <ajax:ScripManager> control to replace the correct value on the page with the new value
But, even in the first I have difficulties, I can send a JSON string, but it will always be surrounded with XML information!
Can anyone (or maybe Jeff) point to a nice "how-to" since scratch? Thank you.

Well, I doubt StackOverflow uses UpdatePanel - more likely it uses jQuery / load to simply update a div, using ASP.NET MVC as the source (rather than ASP.NET vanilla, which has a more complex page cycle).
With this approach, it is trivial... the jQuery examples tab largely says it all.
Re returning the Json - that is simply return Json(obj); from the controller in ASP.NET MVC - but personally I'd return the html (simpler).

Before you dismiss the UpdatePanel I suggest you have a read of this post I did - http://www.aaron-powell.com/blog/august-2008/optimising-updatepanels.aspx. It looks at how to optimise UpdatePanels and it can lead to some performance increases if done well.
I also did a post - http://www.aaron-powell.com/blog/august-2008/paging-data-client-side.aspx which looks at doing client-side templating with jQuery and MS AJAX. I look at how to read a web service with JavaScript and if you download the sample you'll see how to send data client-side to a web service.
But this video cast on the ASP.NET website may also be of use - http://www.asp.net/learn/ajax-videos/video-82.aspx. It's on how to extend web services for script service capabilities.

Related

Manipulating a webpage by its source

I have googled this with a couple of differing terms and I could not find my solution. What I want to do is to manipulate a webpage by editing its source, for example removing a part from the code maybe a div or so. I know how to get the source of a webpage and know how to change the code but I have no idea how to manipulate the page instantly, by for example removing an element.
Your help would be appreciated!
If you want to manipulate client code (HTML) what you need is Ajax.
You can use JQuery javascript library to manipulate html of a page adding, editing and removing html tags, scripts, etc.
Here you can find a decent tutorial as a start point.
If you want to manipulate server code (C# codebehind) what you need is creating a web project in visual studio (ASP.NET Web Application)
EDIT: As commented by #CSharpened both solutions are not mutual exclusive. You can have an ASP.NET Web application that uses Ajax to manipulate UI. In fact lot of people does that.
I would consider using AJAX. You can use either javascript or jquery coupled with html, asp.net and C# to achieve the results you are after.
For simple editing like removing divs or collapsing menus etc simple Javascript or jquery will suffice. However changing the coding of the page requires you to use AJAX or similar.

jQuery.load() with sitefinity

I'm going to develop a website which uses ajax to load pages. The cms behind it, is going to be Sitefinity. The problem is I don't know if it's possible to load the pages of sitefinity with jQuery.Load() or any other ajax technique.
Problems with sitefinity:
- I'm able to get the page object of sitefinity, but i need the rendered HTML.
- I'm going to make the pages in the CMS and each page will have a html, header, body tag etc. And I just need the main content of the page, so i'll have to strip the html aswell!
I've been searching alot, but haven't encountered a solution. If someone could give me tips where to search, or how to do it, I'll appreciate it alot!
A more efficient way to pull the pages in would be to connect to the Sitefinity WCF service with jQuery. You will receive JSON page data via AJAX that you can use to compose your page.
Your project's /Sitefinity/services/ folder is filled with .svc service files that you can query to get various items such as pages (/Sitefinity/services/pages/PagesService.svc/), images, blog posts, etc.
The documentation for using those services from jQuery is a little sparse at this point, but they are actively being improved.
See: Sitefinity Documentation Calling Sitefinity RESTful WCF services from Client Side
And this is a good example (non specific to Sitefinity) on how to call WCF services from jQuery.
One note: Sitefinity is very modular and serves pages and content items separately, you may need to query for a page first to find out what content items need to be queried.
Ask on the SiteFinity support forums. The devs are pretty good about answering questions on there.
Yes, it's possible to retrieve content from Sitefinity via .load(). You can use only a portion of the returned document by doing something like the example below.
$('#empty-container').load('sitefinity-page #main-content');

Creating a widget

Hi i want to create a widget which can be embedded on other websites similar to the twitter profile widget, an example is here;
http://twitter.com/about/resources/widgets/widget_profile
The way i would approach this is to return the data in json format via my wcf, the problem is looking at the twitter example there seems to be some javascript and i am not to clued up on the purpose. My question to the more experienced devlopers is am i on the right track and what else will i need to do. Thanks alot
The purpose of the javascript would be to actually call your wcf service to retrieve data and write the html results to the screen. In the twitter example, many options are set inside a javascript object that is used to manage the configuration (background color, username, etc). You can return json, and then take the values from json and plug them into an html template on the client side. If you want this to be used on other sites however, I would probably avoid the use of jquery as you can't be sure the user has included it, and so you would need to include it. And then you have versioning issues if you use an older version, and the website your widget is on wants to use a newer version.
There is an interesting blog post that explains how to create a widget, loading jquery and css safely, making JSONP calls and more:
How to build a web widget (using jQuery)

How to read html content of Ajax based site

I would like to know how the HTML source of ajax based sites can be read using HttpWebRequest / HttpWebResponse (That is reading the contents of a website at server side). The problem that I'm facing is that I'm unable to read parts of the webpage which uses Ajax or stuffs like UpdatePanel.
My application is in ASP.NET / C#, so can't think of using stuffs like Browser control or mshtml.dll since I would not be able to serve multiple requests.
Thanks in advance.
this is going to be difficult.
I know you said you don't want to use Browser control, but I'm going to say it anyway. You will most probably be better off using a Browser control. The reasons are as follow:
AJAX sites make multiple calls from the browser to the server to obtain the required view.
The multiple calls are being performed via JavaScript
The data returned from the server may be reformatted by JavaScript before being updated onto the view.
If you are going to do this using HttpWebXyz functions, you will have to do the following:
Make the relevant calls to get the initial page source.
Parse the page for JavaScript.
Evaluate/execute the JavaScript. This may include providing the relevant implementation for functions such as alert and making subsequent calls to the server.
Depending on the complexity of the AJAX site, you may want to reconsider using the browser control. Complex sites are easier process by the control. If the site is simple enough, you may survive parsing and executing the required JavaScript.
This example uses a deprecated class to parse JavaScript.
You may want to explore ICodeCompiler and its relevant classes for the new approach.
Good luck.

textbox autocomplete

how do i make an autocomplete textbox in asp?
but i need to get the autocomplete data by querying the database.
I dont really know how to explain this, sory if theres not enough detail.
i cant use ajax, because i think i will have compability issues with my old app.
so im thinking of doing this using java script. or is there a way to do this by using .net?
im using C# for codebehind. thanks
It's going to be a lot of effort without using some third party autocomplete I think - not sure what you mean by 'I can't use ajax', but how about using the ASP.NET AJAX autocomplete control, setting the ServiceMethod property to a static Page Method in your code behind? That keeps it contained within your page at least.
The Page Method can go off to your database, and return a String[] of results.
If you decide to use it, you'll need to set the EnablePageMethods property to true in the <asp:ScriptManager> control.
AJAX is JavaScript. It's JavaScript using the XMLHttpRequest object to make the asynchronous request. Here's an article about it and ASP.NET.
If you want to know more about AJAX, (Asynchronous JavaScript and XML), I'd check out Wikipedia first. If you want books on it, there are a ton. I recommend Programming ASP.NET AJAX by Christian Wenz (O'Reilly And Associates).
if you dont want to uses ajax library, try jquery
there are many plugin autocomplete or suggest textbox for jquery
try this one
http://www.vulgarisoip.com/2007/08/06/jquerysuggest-11/
The ASP.NET AJAX framework works for ASP.NET 2.0 & above. As such it will not work in Visual Studio 2003 environment.
Anthem.NET is a free, cross-browser AJAX toolkit/framework for the ASP.NET development environment that works with both ASP.NET 1.1 and 2.0 -
http://sourceforge.net/projects/anthem-dot-net
For your autocomplete requirement, you can consider using the jQuery Autocomplete Plugin
It requires very less programming. Check the demo & code sample here - http://docs.jquery.com/Plugins/Autocomplete
It's autocomplete() method takes a URL or array to populate your autocompletion list. You can pass the URL of the page that fetches the results from the database directly.

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