Overriding __doPostBack

[Mike Dunn]

I would like to change the name of the _doPostBack
function emmitted by the ASP.NET framework to prefix it
with an ordinal number i.e. the page should show
<script language="javascript">
<!--
function _369__doPostBack(eventTarget,
eventArgument) {
var theform =
document.frmRetailTenantGadget;
theform.__EVENTTARGET.value = eventTarget;
theform.__EVENTARGUMENT.value =
eventArgument;
theform.submit();
}
// -->

</script>
The reason for this is I am working on a portal server and
the output form multiple aspx pages ends up in the same
HTML page. Multiple declarations of __doPostBack cause a
problem in the page. I have found one way to do this is to
override the page render event thus

protected override void Render
(HtmlTextWriter writer)
{
StringBuilder stringBuilder = new
StringBuilder();
StringWriter stringWriter = new
StringWriter(stringBuilder);
HtmlTextWriter htmlWriter = new
HtmlTextWriter(stringWriter);

base.Render(htmlWriter);

string html =
stringBuilder.ToString();

// Prepend postback scripts with
gadget ids
html = html.Replace
("__doPostBack", "_" + GadgetId + "__doPostBack");

writer.Write(html);
}

This works but I believe it could cause a problem with
performance as the find replace is an expensive operation.

Does anyone know a better (faster? more elegant?) way of
doing this

Regards

Mike

 

[Teemu Keiski]

See this thread on ASP.NET forums

Modifying postback script:
http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=62695

--
Teemu Keiski
MCP, Designer/Developer
Mansoft tietotekniikka Oy
http://www.mansoft.fi

ASP.NET Forums Moderator, www.asp.net
AspAlliance Columnist, www.aspalliance.com

Email:
(e-mail address removed)

 

[vMike]

Another possible solution (not mine) but it works. I don't know how much
this slows things down, but it works well for replacing items in the output.
I use this to fix the Netscape bug in 1.1, but you could use it for other
things.

Protected Overrides Sub Render(ByVal writer As HtmlTextWriter)

Dim _stringBuilder As StringBuilder = New StringBuilder()
Dim _stringWriter As StringWriter = New StringWriter(_stringBuilder)
Dim _htmlWriter As HtmlTextWriter = New HtmlTextWriter(_stringWriter)
MyBase.Render(_htmlWriter)
Dim html As String = _stringBuilder.ToString()
Dim start As Integer = html.IndexOf("document._ctl1:_ctl0;")
html = html.Replace("document._ctl1:_ctl0", "document._ctl1__ctl0")
end if
writer.Write(html)

End Sub