Is it possible to do asynchronous post-back without any page rendering (even no partial rendering as it done with AJAX update-panel)?
I need it to be completely transparent to the user.
Update:
The page contains nested repeaters, with buttons inside repeater's itemtemplate.
When buttons are clicked there is a partial-rendering.
I don't want this.
I'm not quite sure what you mean. If the presentation layer does not contain any content that will be affected by the purpose of the AJAX request, then you won't have any page rendering, full or partial.
You can assess the AJAX response using Firebug or Fiddler2 to name a couple of tools.
EDIT
In response to your comment,
Set ChildrenAsTriggers = false on the <asp:UpdatePanel ...> if you don't want the content to be re-rendered in response to a child control initiating a partial postback. It is set to true by default.
You can set ChildrenAsTriggers = false and then explicitly set an <asp:AsyncPostBackTrigger> in the <Triggers> section of the UpdatePanel for those children and their event(s) that you do want the content of the UpdatePanel to be re-rendered for.
You could do the regular AJAX-dance, and just direct it to a separate handler for doing what you want, without any rendering. Could that work for your scenario? If not, can you elaborate on what you want to acheive?
Yes. I am assuming you are talking about ASP.Net, as you mentioned an update panel.
ASP.Net AJAX will automatically expose web methods on a page and allow you to call those completely on the client. Try this page for more info on exposing web services to client side AJAX.
Related
suppose i have many heavy control is on the page. as for example i have three gridview populated on the page and one gridview & button is inside the updatepanel. from this scenario we can understand that there will be huge viewstate on the page. so i want to know that if i click on button inside the updatepanel then all the viewstate will be submitted to server during partial postback or not. if huge viewstate submit to server and comes back to client then what is the advantage of partial postback because response time will be slower. so tell me how could i tune up the code that only required things will only submit to server. discuss the partial postback concept in detail as a result we can take right action to have good performance. thanks.
+1 to geek!
If you are concerned about the performance of your page(s), I would also recommend using ListView instead of GridView:
https://web.archive.org/web/20211020153238/https://www.4guysfromrolla.com/articles/122607-1.aspx
http://weblogs.asp.net/scottgu/archive/2007/08/10/the-asp-listview-control-part-1-building-a-product-listing-page-with-clean-css-ui.aspx
http://basgun.wordpress.com/2007/12/27/listview-control-in-aspnet-35-1/
http://basgun.wordpress.com/2007/12/28/listview-control-in-aspnet-35-2/
http://basgun.wordpress.com/2007/12/29/listview-control-in-aspnet-35-3/
http://basgun.wordpress.com/2007/12/30/listview-control-in-aspnet-35-4/
You can also visit Matt Berseth's blog to see how ListView can get very handy (and neat) for different types of development scenarios:
http://mattberseth.com/blog/listview/
it's important to keep in mind that an UpdatePanel's partial postback invokes a full page life-cycle on every single async request.
Please check out following links for pros and cons of the update panel.
Why ASP.NET AJAX UpdatePanels are dangerous
Why you should not place your whole site in an UpdatePanel
Are you making these 3 common ASP.NET AJAX mistakes?
so i want to know that if i click on button inside the updatepanel then all the viewstate will be submitted to server during partial postback or not
Yes, it will. The entire page's view state is transmitted (in its entirety) to the server on partial page postback, and the new view state is sent back (in its entirety) from the server back to the client on response.
I'd suggest you use a tool like Fiddler to examine the HTTP traffic between the browser and your server when making a partial page postback. This article provides an overview of using Fiddler - Troubleshooting Website Problems by Examining the HTTP Traffic.
In short, the UpdatePanel is meant as a quick and dirty way to get partial page postbacks without having to worry about client-side script or writing logic on the server to specifically handle a partial page postback. Such simplicity comes at a cost, as you've discovered. :-)
For more control over the content that is sent to and from the server on a partial page postback you need to write client-side script and create server-side methods or services to handle the Ajax requests. These articles offer various techniques for providing such functionality:
Accessing JSON Data From an ASP.NET Page Using jQuery
Using Ajax Web Services, Script References, and jQuery
Using WCF Services with jQuery and the ASP.NET Ajax Library
I have a question about how ASP.NET AJAX partial rendering actually works. Does it:
1) Renders the whole page on the server, transmits the whole page to the client, the client then merges just the area contained in the update panel.
2) Renders the whole page on the server, transmits and merges just the area contained by the update panel.
3) Renders, transmits and merges just the area contained by the update panel.
Thanks,
AJ
2 is the answer - Partial-Page Rendering Overview:
An asynchronous postback behaves much
like a synchronous postback. All the
server page life-cycle events occur,
and view state and form data are
preserved. However, in the rendering
phase, only the contents of the
UpdatePanel control are sent to the
browser. The rest of the page remains
unchanged.
It depends on which method you use. If you use an UpdatePanel then it is almost like a full postback, the page goes through its entire lifecycle and then just the content of the UpdatePanel is sent back to the browser. You could also use something like PageMethods to only send the data that your method needs, and have that method return the new html that you can then place in the page (most likely in some div). This is much more efficent, but takes a little more time to setup. Check out this link for a comparison of UpdatePanel versus PageMethods and how to implement each.
Ok, so the problem is as follows: I'm using jQuery's AJAX in order to make behind the scene calls within the page (on events such as voting an item) and changing the content in the appropriate element. The problem occurs when I mix AJAX with ASP.net's AJAX, more precisely when I try to do a postback AFTER I've used jQuery on the page to perform an action. The page's viewstate is changed and validation fails (which would seem somewhat normal as a matter of fact).
My question is: can I disable the validation somehow so that I can perform postbacks combined with the chaged page viewstate? So far searching on how to disable it yielded no results.
A more practical example is on a comments page where I allow voting the comments and posting new comments as well. So should a user vote a comment and THEN post his own, the page's contents is changed, and thus validation fails. Also, I've tried placing the comment form within an update panel as to prevent the entire page from posting, but it still fails.
Of course I could use an alternate route and have a different page for handling the event and just call that via jQuery's AJAX, but I was wondering if I could do this by combining ASP.net and jQuery.
Thanks in advance.
If you want to disable viewstate verification, you can set it at the page or config level by using Page.EnableViewStateMac = false.
http://msdn.microsoft.com/en-us/library/system.web.ui.page.enableviewstatemac.aspx
It's not necessarily a good idea though because the validation functionality is there to protect from viewstate tampering, which you'll be turning off...
If you're running into issues with invalid viewstate because of jQuery ajax calls, one option is to consider using the Ajax controls, such as the UpdatePanel. You can wrap certain controls and mark the UpdatePanel as conditional to ensure a small round trip. This will not interfere with viewstate and allow you to continue to use viewstate validation and ajax at the same time.
There may be ways to use jQuery ajax calls and not interfere with viewstate validation. Others may be able to highlight this approach.
I have a Repeater control that I bind server-side. It repeats a series of divs, and does so with no problem. I have some buttons that I use to sort the repeater (newest, highest ranked, random) and this works the way it should.
I would like to improve my user experience by making the buttons sort the divs using Ajax/jQuery somehow so that there is no page postback and the user does not lose his/her spot on the page.
Is there a way to use jQuery to access server-side code like this, or use Ajax to re-bind a server-side control?
Thanks... if I need to list more details, please let me know!
EDIT I'm aware of UpdatePanels, but I would prefer not to use them if I don't have to.
Have you considered moving the Repeater's functionality to the client-side?
Doing it that way, functionality like paging and sorting is not very difficult to add. In fact, you can lean on the framework pretty heavily by using ADO.NET data services as the service layer.
It's relatively easy.
Move your repeater to a separate custom control, let's say MyControl. Now repeater in your page becomes uc1:MyControl.
Wrap MyControl into a div:
<div id="mydiv">
<uc1:MyControl ID="MyControl1" runat="server" />
</div>
Create a new page, pgMyControl.aspx, that contains MyControl only.
On your main page, add jQuery handlers to your sort links. Use load method to dynamically replace div contents:
$('#link_sort_random').click(function()
{
$("#mydiv").load("pgMyControl.aspx&sort=random");
}
Use QueryStringParameter in datasource inside MyControl to change order. Or use Request.QueryString in code-behind file.
Using an updatePanel or a jquery Ajax postback are the same thing essentially. Both will ask your code to fetch the new query, then make your control render itself, and then feed the HTML back to the client as a partial page render, and then insert the content in place of the old content in the same DOM location.
It is considerably harder to make JQuery and ASP.NET talk to each other this way due to the nature of web controls and their lifecycle that determines when they render. An updatePanel knows how to call all this, maintain proper viewstate and return the result to the correct location.
In this case, don't make things any harder on yourself, use the updatePanel unless you have some very specific reason not to.
EDIT: If you're having JQuery issues with update panels it is probably due to the fact that new DOM nodes being created. JQuery has the live event to handle this. It will notice when new DOM elements are created and match them against your selector even after the document ready.
Maybe it's an OT, but you can consider to change the way you bind even the client and the server control, using XSLT transformation instead od the classics server controls.
You can find an example here (sorry, it's in italian...).
I need the ability to temporarily turn off the partial page update behavior for an ASP.NET Ajax / UpdatePanel based page. (The reason is to circumvent the issue where IE blocks "automatic file downloads" for downloads generated as a result of this postback, but I don't want to distract from my original question)
I looked at the client side javascript libraries hoping to find a switch somewhere. I think a solution might involve using javascript to override the 'onclick' event handler for the control that acts as the trigger, and then calling "submit" on the form itself..
Also, using the EnablePartialRendering property on the server-side ScriptManager control won't work because that is done when the page is being built. I need to be able to do this as a result of switching a drop down list box.
Any ideas?
Cheers!
/ Sean
Well, after much trial and error, I found two approaches that seemed to work:
Use Javascript to manually submit the top level form associated with the page. This usually has the ID of "form1".
Create a button that is outside of any UpdatePanels and use Javascript to click the button.
I wound up using the second approach, since it allowed me to handle the event with a specific routine without the need to guess that my postback came from a Javascript call.
This is an example of the code that performed the postback:
...
if (isDownload) {
document.getElementById('FullPostbackSubmitter').click();
return;
}
...
Hope this helps someone else!
You can set the EnablePartialRendering property of your ScriptManager to false.