dynamic html production to call ajax post via javascript

I am maintaining a page that creates html (not server controls) elements dynamically and when one changes I need to call the ajax postback. Is that possible? The page that is created can't know ahead of time that it will need to post through ajax....

So long as you add a client-side Event handler to your html control when you create it, yes, you can wire it up to make asynchronous requests:http://www.mikesdotnetting.com/Article.aspx?ArticleID=40. Note, the methodology outlined in the article doesn't make an ASP.NET Ajax request or postback. It differs in that it only makes a call to the server-side method you want to invoke. This can be better than using ASP.NET Ajax, in that you aren't recreating all the controls on the page.

Dynamic generated Controls doesnt work, javascript error

I have an ajax enabled control which has a Dropdownlist that changes the Textbox when index gets changed. It is working fine if I use an ASPX page that contains the control in design time.

However, when I dynamically add this control to the ASPX in run time, I got an error when the Dropdownlist is triggered:

Javascript error: System.InvalidOperationException: A control with ID 'myDropDownList' could not be found for the trigger in UpdatePanel..etc..

What should I do? Please help..

There's a good chance that if you look at your page source you'll find that the dynamic control does not have a clientside Id of 'myDropDownList'. It'll probably have something more complex like ct100_myDropDownList or something.

Two possible fixes: 1) wire up your javascript on something other than the id (e.g. iterate over getElementsByTagName), or 2) render the control's ClientID inside a script tag on the page like: var ddl = '<%= myDropDownList.ClientID %>'

HOpe that helps.

dynamic generated clientside javascript

hi,

how can i register a script on asyncPostBack and can check in the next asynPostback if the script is on side ?

i use ajax with scriptmanager and updatepanel on my website.

sometimes i will give the user (after a asyncPostBack) a alert-message about javascript...

i have tryed following:

PrivateSub RegisterMsg(ByVal strMessageAsString,ByVal strScriptTagAsString)

Dim strScriptAsString ="alert(""" & strMessage &""");"

If (Not Page.ClientScript.IsClientScriptBlockRegistered("key"))Then

ScriptManager.RegisterClientScriptBlock(Me,Me.GetType(),"key", strScript,True)

EndIf

EndSub

the IsClientScriptBlockRegistered-methode every time gives false back...thx

Use ScriptManager.RegisterStartupScript() and drop the IsBlockRegistered check.

now i have:

Private Sub RegisterMsg(ByVal strMessage As String, ByVal strScriptTag As String)
Dim strScript As String = "alert(""" & strMessage & """);"

If (Not Page.ClientScript.IsClientScriptBlockRegistered("key")) Then
ScriptManager.RegisterStartupScript(Me, Me.GetType(), "key", strScript, True)
End If
End Sub

and it is the same...it did not work correct, the IsClientScriptBlockRegistered-Method returns every time false and because of this the script will be written a second one, and third one and so on...

Hi,

Since the script is created dynamically, it won't be persisted between different requests.

So, before the method is called on the second request, this script block does not exist.

And my suggestion is you don't have to call this multiple times, just call it on initial request and it'll always stay on the page since the page isn't fully refreshed.

the problem is that the appl. dont makes really postbacks during running, only partial postbacks...

and my wish is that i will register and unregister scripts during partial postbacks...how can i do it ?

For partial postback, you can register new scripts.

But you can't unregister existed scripts on server side.

Has there been any progress made on this issue? I am just experiencing this now.

I've overriden OnInit with the following (similar) code:

if (!Page.ClientScript.IsClientScriptBlockRegistered(typeof(Page),"MyScript")
{
// use StringBuilder/StringWriter to build script
 ScriptManager.RegisterClientScriptBlock(this,typeof(Page),"MyScript",sb.ToString(),true);
}

But the conditional is always true so the script gets recreated every time there is an asyncPostback.

One thing I noticed (using Firebug in Firefox) is on the initial load of the page the script is created

within the form and then on each successive asyncPostback a new script is created in the <head>.

Why is there no IsClientScriptBlockRegistered function in the ScriptManager class? Is that the problem?

That the Page.ClientScript and ScriptManager are looking at two different collections of scripts?

dyanamic creation of toolkit controls?

Hi,

Can we create ajax controls dynamically i.e. in javascript? For example, I wish to create a tab control dynamically? Can we do that?

--jon

You can definitely create your AJAX controls/behaviors using the $create() statements (most likely called/hooked-up from the application init function). You should create a few Ajax controls declaratively in the page and then view the source it outputs to get an idea of the syntax needed.

dropshadowextender - how to show and hide in javascript

Hello

How would i turn a dropshadowextender on and off in javascript. In essence i need to show and hide teh drop shadow at different points.

Thanks

andrea

Hi Andrea,

The easiest approach is to set the width of the drop shadow to0, like the sample page does inchkShadow'sonclick. You can do it using$object('dsBehavior').set_Width(0);.

Thanks,
Ted
thanks :)

DropDownExtender inside UpdatePanel = bug

Hello,

I'm abusing of the UpdatePanels, love em...

But whenever I try to put the dropdownextender inside an updatepanel I get a javascript error about an invalid padding unit?!

I'm not sure but I think it's because its inside updatepanel(s)...

Anyone seen this?

No?