Javascript code to recursively search for a element given the element's Id
in [ASP .NET]
|
From: Cal Who on 22 May 2010 14:38 I need Javascript code to recursively search for a element given the element's Id so that I can modify a elements attributes. I do not use JQuery but I believe that once when I was searching the Internet for something else I saw that JQuery has a function called $ that did just that. And the author showed the Javascript code from that library. I'm not sure if that is what I need but now that I want it I can't find it. Bottom line: Can you point to (or supply) Javascript code to recursively search for a element given it's Id? Thanks in advance
From: Registered User on 22 May 2010 14:58 On Sat, 22 May 2010 14:38:38 -0400, " Cal Who" <CalWhoNOSPAM(a)roadrunner.com> wrote: >I need Javascript code to recursively search for a element given the >element's Id so that I can modify a elements attributes. > >I do not use JQuery but I believe that once when I was searching the >Internet for something else I saw that JQuery has a function called $ that >did just that. And the author showed the Javascript code from that library. >I'm not sure if that is what I need but now that I want it I can't find it. > >Bottom line: Can you point to (or supply) Javascript code to recursively >search for a element given it's Id? > Perhaps you mean something like var element = document.getElementById('someID'); regards A.G.
From: Cal Who on 22 May 2010 18:19 That's what I thought but lost confidence when it returned null in the following: <script type="text/javascript"> function SetMargins(id) { var element = document.getElementById(id); .... Which is in the .master and the id looks like I'd expect: id = "ctl00_BottomImageCPH_QQQ" I called it from and aspx.vb file <asp:Content ID="Content8" runat="server" ContentPlaceHolderID="BottomImageCPH"> <script type="text/javascript"> SetMargins('<%=QQQ.ClientID%>'); </script> <div runat="server" id="QQQ" style="margin-left: 10%; margin-right: 10%;" > .... Why the null?? Thanks
From: Mark Rae [MVP] on 22 May 2010 19:18 " Cal Who" <CalWhoNOSPAM(a)roadrunner.com> wrote in message news:ht9l9g$dti$1(a)news.eternal-september.org... > Why the null?? Because of ASP.NET's control ID munging. var control = document getElementById('<%=MyControl.ClientID%>'); -- Mark Rae ASP.NET MVP http://www.markrae.net
From: Registered User on 22 May 2010 19:31
On Sat, 22 May 2010 18:19:25 -0400, " Cal Who" <CalWhoNOSPAM(a)roadrunner.com> wrote: >That's what I thought but lost confidence when it returned null in the >following: > ><script type="text/javascript"> > >function SetMargins(id) { > >var element = document.getElementById(id); > >... > >Which is in the .master and the id looks like I'd expect: > >id = "ctl00_BottomImageCPH_QQQ" > > > >I called it from and aspx.vb file > ><asp:Content ID="Content8" runat="server" >ContentPlaceHolderID="BottomImageCPH"> > ><script type="text/javascript"> > >SetMargins('<%=QQQ.ClientID%>'); > ></script> > > ><div runat="server" id="QQQ" style="margin-left: 10%; margin-right: 10%;" > > >... > > >Why the null?? > From the second snippet it appears the SetMargins method is being called as the document is rendered. The document is rendered from top to bottom. If SetMargins is called before control QQQ is rendered to the document, the document won't find the control, and document.getElementById will return null. You may have to read that last sentence a couple of times ;) I would suggest attaching a javascript method to the page body's onload event. That method will be called after the page has been rendered. From within that method make the call to SetMargins. regards A.G. |