How can a server control within a template be sensitive to the data context?

Question

Let's say a control X has a template called RowTemplate.

So X's markup would be like:

<foo:X>
    <RowTemplate>
        <foo:Y>...</foo:Y>
    </RowTemplate>
</foo:X>

My question is: How can the Y control be sensitive to the data context? I know I can use template inline tags to get access to the data context: <%# Eval("Id") %>, but I cannot pass this information to Y because template inline tags are not allowed in server controls.

So I don't know how I could use the Object's Id (Eval("Id")) in Y.

Answer 1

By adding a handler to the ItemDataBound event (or some other similar event on your foo:X control), you can access controls in your row template. My example code is from a DataList, so your event handlers will probably be different.

In the code behind - wire up the event handler:

protected override void OnInit(EventArgs e)
{
    base.OnInit(e);

    foo.ItemDataBound += new DataListItemEventHandler(foo_ItemDataBound);
}

Then in the event handler, access the controls in your row. Your data might not be a DataRow, so change that as needed.

void foo_ItemDataBound(object sender, DataListItemEventArgs e)
{
    Control fooY = (e.Item.FindControl("foo:Y") as Control); //Replace foo:Y with the ID for foo:Y
    DataRow data = e.Item.DataItem as DataRow;
    fooY.SomeProperty = data["id"];
}