Client Side Web Development

Re: Javascript: detect Page.IsValid and IsPostBack

NC01 — Tue, 18 Aug 2009 16:35:18 GMT

What does "owned" mean? And why should I care anyways?

NC...

Re: Javascript: detect Page.IsValid and IsPostBack

Fras77 — Tue, 18 Aug 2009 15:45:59 GMT

NC01, people are still reading this thread and finding it useful even now, and you're getting owned every time someone reads it.

Re: Javascript: detect Page.IsValid and IsPostBack

CptCoathanger — Wed, 04 Mar 2009 17:20:25 GMT

Nice one, dude. Should have thought of it myself really! Don't pay any attention to the miserable chap bemoaning you resurrecting a thread, he must have a little sand in his vagina.

Re: Javascript: detect Page.IsValid and IsPostBack

d4446 — Tue, 27 Jan 2009 18:24:34 GMT

It helped me and I believe you contributed more than all previous posts.

Re: Javascript: detect Page.IsValid and IsPostBack

RobSil — Wed, 22 Oct 2008 19:22:34 GMT

NC01:
Because the post has been resolved and you really did not contribute much if anything different than what was already posted.

NC...

No contribution? I shortened your original post into not requiring ANY server-side coding, you don't consider that a contribution? This means no custom variables (a string at that?) and no need to get/set them in the Page_Load EVERY time you implement this approach.

Since you seem willing to debate minute details about an implementation... why would you ever track the exact same variable twice in your code-behind if you don't need to? Not only that, your tracking it as a string rather than a bool, which is much more in-efficient. Finally, your assuming that it will be set in every Page_Load which means the user would need to repeat unnecessary code in his Page_Load's. Also worth pointing out that in the first response you made in this thread, you used a hidden element when it is not needed.

Back to your previous post, this thread will be read for some time I am sure (clearly if I found it year(s) after it was originally discussed), so why not attempt to provide the best/easiest solution possible?

Re: Javascript: detect Page.IsValid and IsPostBack

NC01 — Wed, 22 Oct 2008 19:08:32 GMT

Because the post has been resolved and you really did not contribute much if anything different than what was already posted.

NC...

Re: Javascript: detect Page.IsValid and IsPostBack

RobSil — Wed, 22 Oct 2008 19:05:45 GMT

NC01:
Why reply on a post that is over a year old?

NC...

Why not? I came across the post researching a problem, so others might as well.

Re: Javascript: detect Page.IsValid and IsPostBack

NC01 — Wed, 22 Oct 2008 19:03:34 GMT

Why reply on a post that is over a year old?

NC...

Re: Javascript: detect Page.IsValid and IsPostBack

RobSil — Wed, 22 Oct 2008 18:36:26 GMT

To extend all this a little bit further...

Just use the postback variable already in the page.

HTH,

Robin

Re: Javascript: detect Page.IsValid and IsPostBack

NC01 — Wed, 05 Sep 2007 14:51:40 GMT

Never heard of a 'Restricted_COER_Attachments'. Maybe it is coming from something that your 3rd party app is inserting?

The idea that jsearles presented should also work however:

In the aspx file:

return (serverSidePostBack == 'Y') ? true : false;
}
</script>

In the aspx.cs file:

// Declare outside of any method:
public string clientSideIsPostBack = "N";

private void Page_Load(object sender, System.EventArgs e)
{
if ( this.IsPostBack )
this.clientSideIsPostBack = "Y";
else
this.clientSideIsPostBack = "N";
}

NC...

Re: Javascript: detect Page.IsValid and IsPostBack

jsearles — Wed, 05 Sep 2007 11:11:26 GMT

What i have always done to deal with this is declare a global variable in javascript and then set it after the initial page load. For example: var isPostBack = false; function pageLoad() { if (!isPostBack) { // Do stuff isPostBack = true; } } It's always worked for me.

Re: Javascript: detect Page.IsValid and IsPostBack

jon_angel — Tue, 04 Sep 2007 22:08:04 GMT

Many thanks, I'm almost there, but I'm getting a weird error 'Restricted_COER_Attachments' does not contain a definition for 'clientSideIsPostBack'

Intellisense sure finds a definition, but Compilation doesn't. If I add an explicit definition in the aspx.cs, Intellisense tells me the HtmlHiddenInput object is defined twice. Dragging an Input (Hidden) from the HTML section of the toolbox makes no difference.

However if I Build Page it works fine (?!)

Re: Javascript: detect Page.IsValid and IsPostBack

NC01 — Fri, 31 Aug 2007 16:51:03 GMT

It's easy enough to detect whether a PostBack has occurred client-side:

In the aspx file:

  if ( document.getElementById('clientSideIsPostBack').value == 'Y' )
   return true;
  else
   return false;
}
</script>
</form>

In the aspx.cs file:

private void Page_Load(object sender, System.EventArgs e)
{
if ( this.IsPostBack )
this.clientSideIsPostBack.Value = "Y";
else
this.clientSideIsPostBack.Value = "N";
}

NC...

Re: Javascript: detect Page.IsValid and IsPostBack

jon_angel — Fri, 31 Aug 2007 16:07:17 GMT

Cookies probably aren't an option, according to policy. What would work is detecting that the RequiredFieldValidator has fired and is displaying its error message. But in debug mode I couldn't find a property of the validator nor the RadioButtonList that it validates that tells me this.

Re: Javascript: detect Page.IsValid and IsPostBack

mattmeckes — Fri, 31 Aug 2007 15:45:15 GMT

If you are doing this client side I dont think you can check if it is posted back. You could create a cookie when the page is first loaded. You can store the value of the global client side variable Page_IsValid in the cookie. If the page is posted back the cookie will already exist and you can check if the original was valid.