Programmatically click asp.net button via javascript?

[Cathryn Johns]

Hi

I have a server-side (asp.net) method that can be called by clicking a
<asp:button> on my webpage. This method should also be called every n
seconds, so I've set up a javascript timer which fires every n seconds.
The problem is that I then don't know how to call the server-side
method.

I figured that since I already have a button calling that method, I
could just emulate the button click, but I've tried two methods and
neither seem to work. document.Alloca tionsForm.LoadB utton.click()
complains that document.Alloca tionsFrom.LoadB utton is null or doesn't
exist, and __doPostBack('L oadButton', '') does a postback but doesn't
actually execute the method.

[Eliyahu Goldin]

Re: Programmaticall y click asp.net button via javascript?

In situations like yours I usually introduce a hidden input control for
passing an action code from client to server side. It is much simpler than
trying to mimic exact client-side button click handling.

Eliyahu

"Cathryn Johns" <cjohns@gmail.c om> wrote in message
news:1130848841 .282492.173550@ g44g2000cwa.goo glegroups.com.. .[color=blue]
> Hi
>
> I have a server-side (asp.net) method that can be called by clicking a
> <asp:button> on my webpage. This method should also be called every n
> seconds, so I've set up a javascript timer which fires every n seconds.
> The problem is that I then don't know how to call the server-side
> method.
>
> I figured that since I already have a button calling that method, I
> could just emulate the button click, but I've tried two methods and
> neither seem to work. document.Alloca tionsForm.LoadB utton.click()
> complains that document.Alloca tionsFrom.LoadB utton is null or doesn't
> exist, and __doPostBack('L oadButton', '') does a postback but doesn't
> actually execute the method.
>[/color]

[Phillip Williams]

RE: Programmaticall y click asp.net button via javascript?

Try:

var btn = document.getEle mentById(btnNam e);
if (btn) btn.click();

as I did in this sample:

http://www.societopia.net/Samples/asppage_buttons.aspx

--
HTH,
Phillip Williams

http://www.societopia.net

http://www.webswapp.com

"Cathryn Johns" wrote:
[color=blue]
> Hi
>
> I have a server-side (asp.net) method that can be called by clicking a
> <asp:button> on my webpage. This method should also be called every n
> seconds, so I've set up a javascript timer which fires every n seconds.
> The problem is that I then don't know how to call the server-side
> method.
>
> I figured that since I already have a button calling that method, I
> could just emulate the button click, but I've tried two methods and
> neither seem to work. document.Alloca tionsForm.LoadB utton.click()
> complains that document.Alloca tionsFrom.LoadB utton is null or doesn't
> exist, and __doPostBack('L oadButton', '') does a postback but doesn't
> actually execute the method.
>
>[/color]

[intrader]

Re: Programmaticall y click asp.net button via javascript?

On Tue, 01 Nov 2005 04:40:41 -0800, Cathryn Johns wrote:
[color=blue]
> Hi
>
> I have a server-side (asp.net) method that can be called by clicking a
> <asp:button> on my webpage. This method should also be called every n
> seconds, so I've set up a javascript timer which fires every n seconds.
> The problem is that I then don't know how to call the server-side
> method.
>
> I figured that since I already have a button calling that method, I
> could just emulate the button click, but I've tried two methods and
> neither seem to work. document.Alloca tionsForm.LoadB utton.click()
> complains that document.Alloca tionsFrom.LoadB utton is null or doesn't
> exist, and __doPostBack('L oadButton', '') does a postback but doesn't
> actually execute the method.[/color]

Candidate for Ajax?

[Cathryn Johns]

Re: Programmaticall y click asp.net button via javascript?

Nope, that doesn't work either - if (btn) just returns false. I assume
that this is because in your sample, the button is a regular html
<input type="button".. .>, whereas mine is an actual asp.net button
(<asp:button ....>).

Any ideas on how to click an asp.net button?

Phillip Williams wrote:[color=blue]
> Try:
>
> var btn = document.getEle mentById(btnNam e);
> if (btn) btn.click();
>
> as I did in this sample:
>
> http://www.societopia.net/Samples/asppage_buttons.aspx
> --
> HTH,
> Phillip Williams
> http://www.societopia.net
> http://www.webswapp.com
>
>
> "Cathryn Johns" wrote:
>[color=green]
> > Hi
> >
> > I have a server-side (asp.net) method that can be called by clicking a
> > <asp:button> on my webpage. This method should also be called every n
> > seconds, so I've set up a javascript timer which fires every n seconds.
> > The problem is that I then don't know how to call the server-side
> > method.
> >
> > I figured that since I already have a button calling that method, I
> > could just emulate the button click, but I've tried two methods and
> > neither seem to work. document.Alloca tionsForm.LoadB utton.click()
> > complains that document.Alloca tionsFrom.LoadB utton is null or doesn't
> > exist, and __doPostBack('L oadButton', '') does a postback but doesn't
> > actually execute the method.
> >
> >[/color][/color]

[Phillip Williams]

Re: Programmaticall y click asp.net button via javascript?

Nope :-)

The buttons in my demo are <asp:button> and they do work. Another demo is
the City of North Vancouver's website (which I developed) where the search
button is also an asp:button and working using btn.Click() too.
--
HTH,
Phillip Williams

http://www.societopia.net

http://www.webswapp.com

"Cathryn Johns" wrote:
[color=blue]
> Nope, that doesn't work either - if (btn) just returns false. I assume
> that this is because in your sample, the button is a regular html
> <input type="button".. .>, whereas mine is an actual asp.net button
> (<asp:button ....>).
>
> Any ideas on how to click an asp.net button?
>
> Phillip Williams wrote:[color=green]
> > Try:
> >
> > var btn = document.getEle mentById(btnNam e);
> > if (btn) btn.click();
> >
> > as I did in this sample:
> >
> > http://www.societopia.net/Samples/asppage_buttons.aspx
> > --
> > HTH,
> > Phillip Williams
> > http://www.societopia.net
> > http://www.webswapp.com
> >
> >
> > "Cathryn Johns" wrote:
> >[color=darkred]
> > > Hi
> > >
> > > I have a server-side (asp.net) method that can be called by clicking a
> > > <asp:button> on my webpage. This method should also be called every n
> > > seconds, so I've set up a javascript timer which fires every n seconds.
> > > The problem is that I then don't know how to call the server-side
> > > method.
> > >
> > > I figured that since I already have a button calling that method, I
> > > could just emulate the button click, but I've tried two methods and
> > > neither seem to work. document.Alloca tionsForm.LoadB utton.click()
> > > complains that document.Alloca tionsFrom.LoadB utton is null or doesn't
> > > exist, and __doPostBack('L oadButton', '') does a postback but doesn't
> > > actually execute the method.
> > >
> > >[/color][/color]
>
>[/color]

[CJ]

Re: Programmaticall y click asp.net button via javascript?

Found the problem, and you're right, it had nothing to do with asp.net
buttons :-)

The button is in a .ascx user control which is sitting in a .aspx page,
and I had to prefix the button name with the name of the user control
WebUI element. Once I figured that out, it all worked smoothly.