Accessing ASP Button visible property in JavaScript

[Doogie]

Hi,
I am trying to access the visible property of an ASP button inside
javascript to no avail. Here's what my button control looks like:

<asp:Button id="btnAcceptTrips" name="btnAcceptTrips" runat="server"
Text="Accept Trips" Visible="False">

Here's my test method:

function test(checkbox)
{
if (checkbox.checked)
{
document.Form1.btnAcceptTrips.visible = true
}
}

I get an error saying this object is null or doesn't exist. So I
played around with this. I can verify that I can access the
btnAcceptTrips object within javascript, I can even access the
btnAcceptTrips object name property value, but visible doesn't appear
to be accessible. I've tried "Visible" and "visible".

Does anyone know how to get access to this value?

 

[Randy Webb]

Doogie said the following on 6/18/2007 11:08 AM:

Hi,
I am trying to access the visible property of an ASP button inside
javascript to no avail. Here's what my button control looks like:

<asp:Button id="btnAcceptTrips" name="btnAcceptTrips" runat="server"
Text="Accept Trips" Visible="False">

What your server code looks like is irrelevant. What is important is the
HTML that the browser gets.

Here's my test method:

function test(checkbox)
{
if (checkbox.checked)
{
document.Form1.btnAcceptTrips.visible = true
}
}

I get an error saying this object is null or doesn't exist. So I
played around with this. I can verify that I can access the
btnAcceptTrips object within javascript, I can even access the
btnAcceptTrips object name property value, but visible doesn't appear
to be accessible. I've tried "Visible" and "visible".

Does anyone know how to get access to this value?

Visibility is a property of the style object.

..style.visibility = "visible"
..style.visibility = "hidden"

 

[Doogie]

Hi Randy,
This works - but to a point. If I start the app off with the button
visible like so:

<asp:button id="btnAcceptTrips" runat="server" Text="Accept Trips"
Visible="True" name="btnAcceptTrips"></asp:button>

then everything works fine.

But if I set the visibility property of the control to false like this
(and this will be the way my app neds to be have:

<asp:button id="btnAcceptTrips" runat="server" Text="Accept Trips"
Visible="False" name="btnAcceptTrips"></asp:button>

and then start the app, when I try to set the .style.visibility value
I get this error:

'document.Form1.btnAcceptTrips.style' is null or not an object.

 

[-Lost]

Hi Randy,
This works - but to a point. If I start the app off with the button
visible like so:

<asp:button id="btnAcceptTrips" runat="server" Text="Accept Trips"
Visible="True" name="btnAcceptTrips"></asp:button>

then everything works fine.

But if I set the visibility property of the control to false like this
(and this will be the way my app neds to be have:

<asp:button id="btnAcceptTrips" runat="server" Text="Accept Trips"
Visible="False" name="btnAcceptTrips"></asp:button>

and then start the app, when I try to set the .style.visibility value
I get this error:

'document.Form1.btnAcceptTrips.style' is null or not an object.

Quote what you respond to so everyone can follow along without having to
reference threads that may not be available.

Also, just like Mr. Webb said, you need to worry about (valid) HTML.
Without it, JavaScript cannot behave consistently.

Start with this and or modify until you get what you want.

<form id="form1">
<button name="button1" type="button">Accept Trips</button>
</form>

<script>
document.forms['form1'].elements['button1'].style.visibility = 'hidden';
</script>

 

[Doogie]

Quote what you respond to so everyone can follow along without having to reference threads

that may not be available.

Why would a reference thread not be available (just curious).
Personally, I find the additional quotes annoying to parse through.

Also, just like Mr. Webb said, you need to worry about (valid) HTML. Without it, JavaScript > cannot behave consistently.

What is invalid about my html? I created it directly from within .NET
by dumping the control onto my form and setting the visible property
to false (which is what I need). I need this control to be invisible
when the app starts, and then my javascript method will make it
visible or invisible depending on condtions. If I start with the
control visible and run through setting it's visibility in javascript
it works, but if I start with it invisible it does not work.

 

[Randy Webb]

Doogie said the following on 6/18/2007 4:12 PM:

Why would a reference thread not be available (just curious).
Personally, I find the additional quotes annoying to parse through.

Because, in my case, I have already read the message you are replying to
(in fact, I wrote it). And since I have already read it, and not marked
it unread, Thunderbird doesn't show it to me anymore unless I go through
certain steps to view it again. Quoting what you are replying to
prevents that from ever happening.

What is invalid about my html?

Good question Since you posted the server side code (which I said was
irrelevant) nobody would know what the browser got without having an
ASP.NET server to serve it to the browser to see. When posting code
here, post the resulting HTML and not the server code that generates it.

I created it directly from within .NET

I am not a big fan of the HTML that .NET produces.

by dumping the control onto my form and setting the visible property
to false (which is what I need). I need this control to be invisible
when the app starts, and then my javascript method will make it
visible or invisible depending on condtions. If I start with the
control visible and run through setting it's visibility in javascript
it works, but if I start with it invisible it does not work.

Then start with it visible and immediately hide it.