Catching form Submit and PageRequestManager Submit

We want to save some state on an Extender just before the page is posted back or submitted. We were just listening to the form's submit event

$addHandler(form,"submit", this._formSubmitDelegate);

but that doesn't fire when we postback is via a LinkButton so I want to catch that happening and reuse the same delegate.

I looked at using

 $addHandler(Sys.WebForms.PageRequestManager.getInstance(),'endrequest',this._endRequestDelegate);

but add Handler did not like non DOM elements being passed in. I then tried

 Sys.WebForms.PageRequestManager.getInstance().add_endRequest(this.endRequestHandler);

But the value of "this" was not what I was expecting. I am currently trying

if (typeof(Sys.WebForms)!=="undefined" &&typeof(Sys.WebForms.PageRequestManager)!=="undefined"){ Array.add(Sys.WebForms.PageRequestManager.getInstance()._onSubmitStatements,this._formSubmitDelegate); }else { $addHandler(form,"submit",this._formSubmitDelegate); }

This seems to call formSubmitDelegate and all works well. I realise i am accessing _onSubmitStatements which should be considered private. Am I cheating? What is the correct way of doing it?

TIA

Paddeo

Hi Paddeo,

Why the second one doesn't meet your requirement?

It's the recommended way that how a handler is added.

Well when my page is "Posted back" and that postback is caused by something causing validation WebForm_DoPostbackWithOptions is called. At the end of that routine it passes off to a ASP.NET AJAX routine that will do the "postback" using a WebRequest. That does NOT cause our Form Submit event to fire.

I thought I could get around this by trapping both the Submit AND adding to the _onSubmitStatements array (I realise that my eariler post was doing it OR the other) however this is still not enough. If I had a simple AutoPost=True ASP.Net CheckBox that calls _doPostback that exists in the page itself. This does not cause my onSubmitStatements to fire nor does it call DoPostbackWithOptions so yet again I have an issue with reliably catching postbacks and submits.

To this end I am going to give up trying to lazy write to state and just serilaise it every time it changes.

Pat

Saving client state on PropertyChanged event.

Yes, sorry I should have reported back. PropertyChanged is exactly what i changed to and that works much better. Even the approaches above were not enough to catch all the postbacks