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:
[url]http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=62695[/url]

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

ASP.NET Forums Moderator, [url]www.asp.net[/url]
AspAlliance Columnist, [url]www.aspalliance.com[/url]

Email:
[email]joteke@aspalliance.com[/email]


"Mike Dunn" <nospammike.dunn@britishland.com> wrote in message
news:026f01c34637$52dcbf10$a101280a@phx.gbl...

> 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
>
>

[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

"Mike Dunn" <nospammike.dunn@britishland.com> wrote in message
news:026f01c34637$52dcbf10$a101280a@phx.gbl...

> 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
>
>