Setting e.g. 'onclick' on button

jacob · February 4th, 2004, 05:53 PM

I am trying to do a setup where I would like to show only some elements on the page at startup and if some button is clicked show some other stuff. All this without reloading the page; that is, I would like to use java script for toggleing the visibility (CSS) of the elements, but construct the user interface from code behind.

Is it possible in some way to define that a HtmlInputButton should call some java script function (client side)!? As far as I have understood, when I make a

Code:

HtmlInputButton btn = new HtmlInputButton();

then it is equivalent to doing something like...

Code:

<INPUT type='button' runat='server'>

right?! Then how do I set the 'onclick' equivalent? Or is this impossible?

Thanks

Jacob.

Imar · February 4th, 2004, 06:19 PM

Hmmm, what's the point of a *server* side button that does nothing but execute code at the *client*? In that case, why not just an plain ol' HTML button? (input type="button")

An HtmlInputButton will end up as a "input type="submit" button in the browser, so the form gets submitted when you click it. Just as with plain HTML buttons, you can add some code that fires when you click the button. You can use the Attributes collection of the button to add some code to the click handler:

Code:

myDeleteButton.Attributes.Add("onclick", "return(confirm('Are you sure you want to delete this item?'));");

This code will stop the form from being submitted when the user presses the cancel button.
You can use the same technique to call JavaScript functions embedded in the page or in a separate .js file:

Code:

myOtherButton.Attributes.Add("onclick", "return MyJSFunction();");

If you make sure that MyJSFunction returns false, the page will never be submitted to the server, and the button is pure client side.

However, I think this stuff is more confusing than useful. If you do only need a client side button, use a simple HTML button.

Cheers,

Imar

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Imar Spaanjaars
Everyone is unique, except for me.

jacob · February 4th, 2004, 07:30 PM

Thanks Imar... once again a thorough answer!

The thing is that I am generating a questionnaire dynamically from data entered in an XML file, and I want to flip pages using java script.

I believe that when you use HtmlInputButton like this

Code:

new HtmlInputButton("button")

you will actually get a button that does not submit the form.

So I think I can do it this way and use the Attributes.Add method. I will try and then let the forum know.

Thanks again

Jacob.

jacob · February 4th, 2004, 07:34 PM

It works! Thanks a lot again.

Code:

HtmlInputButton btn = new HtmlInputButton("button");
btn.Attributes.Add("onclick", "test(); return false;");

Jacob.

Imar · February 4th, 2004, 07:49 PM

Right, nice solution. I thought that a new HtmlInputButton() would result in a type="submit" button, but I was wrong.

This will work pretty well.

Imar

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Imar Spaanjaars
Everyone is unique, except for me.