ClintID does not work for datagrid template columns controls

[Tudor]

Hello I have a datagrid "dg" which has two template columns. The first
template column contains a button denoted "b" and the second template
column contains a div server control denoted "div" which in turn
contains another grid denoted "dg_second". "dg_second" is bound to
"dg" item data. Of course, for each item from "dg" it is generated a
button "b" and div element "div" which contains a "dg_second". What i
want is to attach a javascript code to "b" in order to alternatively
hide or show the corresponding element "div" from the same line(second
column). Theoretically, it is quite simple to do that: i treat the
itemCreated event of "dg" which is fired for every item creation.
Inside this event, i identify for each item the "b" and "div" elements
and i associate to the "b" element a javascript function having as
argument the ClientID value of the "div" element. The javascript
function will simply hide or show the div element who's id receives in
the parameter. The problem is that in this function, the property
ClientID of "b" and "div" elements DOES NOT return the correct values
that are rendered into html code. More exactly ClientID always returns
"b" and "div" instead of some complicated unique strings. Here it is
the implementation of my itemCreated event

private void itemCreated(object sender,
System.Web.UI.WebControls.DataGridItemEventArgs e) {
if (e.Item.ItemType==ListItemType.Item || e.Item.ItemType==
ListItemType.AlternatingItem ) {
Button b=(Button)e.Item.FindControl("b");
HtmlGenericControl div= (HtmlGenericControl)e.Item.FindControl("div");
String divClientID=div.ClientID;
String js="javascript:setNewContent('" + divClientID+"');return
false;"; b.Attributes["onclick"]=js; }
}

My purpose is to implement a hierarchical grid display.
I would greately appreciate any qualified help for this matter.
Tudor

 

[Teemu Keiski]

I answered this on another group:

It is because basically DataGrid's control hierarchy isn't "clear" yet, that
is this item is just created and it hasn't been added to DataGrid's controls
collection and therefore they have not been assigned full IDs yet.

You could overcome the problem by attaching a handler for DataGrid's
PreRender event and set the ID's there. My code is VB as I had VB IDE open
by the time I read your question, hope it doesn't mind).

Private Sub DataGrid1_PreRender(ByVal sender As Object, ByVal e As
System.EventArgs) Handles DataGrid1.PreRender
For Each dgi As DataGridItem In DataGrid1.Items
Dim b As Button = CType(dgi.FindControl("b"), Button)
Dim div As HtmlGenericControl = CType(dgi.FindControl("div"),
HtmlGenericControl)
Dim divClientID As String = div.ClientID
Dim js As String = "javascript:setNewContent('" + divClientID +
"');return false;"
b.Attributes("onclick") = js
Next
End Sub

And BTW it should work on ItemDataBound as well as on that phase item is
added to the DataGrids controls.
--
Teemu Keiski
MCP,Designer/Developer
Mansoft tietotekniikka Oy
http://www.mansoft.fi

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

Hello I have a datagrid "dg" which has two template columns. The first
template column contains a button denoted "b" and the second template
column contains a div server control denoted "div" which in turn
contains another grid denoted "dg_second". "dg_second" is bound to
"dg" item data. Of course, for each item from "dg" it is generated a
button "b" and div element "div" which contains a "dg_second". What i
want is to attach a javascript code to "b" in order to alternatively
hide or show the corresponding element "div" from the same line(second
column). Theoretically, it is quite simple to do that: i treat the
itemCreated event of "dg" which is fired for every item creation.
Inside this event, i identify for each item the "b" and "div" elements
and i associate to the "b" element a javascript function having as
argument the ClientID value of the "div" element. The javascript
function will simply hide or show the div element who's id receives in
the parameter. The problem is that in this function, the property
ClientID of "b" and "div" elements DOES NOT return the correct values
that are rendered into html code. More exactly ClientID always returns
"b" and "div" instead of some complicated unique strings. Here it is
the implementation of my itemCreated event

private void itemCreated(object sender,
System.Web.UI.WebControls.DataGridItemEventArgs e) {
if (e.Item.ItemType==ListItemType.Item || e.Item.ItemType==
ListItemType.AlternatingItem ) {
Button b=(Button)e.Item.FindControl("b");
HtmlGenericControl div= (HtmlGenericControl)e.Item.FindControl("div");
String divClientID=div.ClientID;
String js="javascript:setNewContent('" + divClientID+"');return
false;"; b.Attributes["onclick"]=js; }
}

My purpose is to implement a hierarchical grid display.
I would greately appreciate any qualified help for this matter.
Tudor