Thread: Updating DDL inside DataList OnChange of DDL outside DataList

OK. I have a datalist containing a number of controls, textboxes and dropdownlists. The relevant ones for this problem are:-
Source
PremiumType
SourcePolicyRef

I have another DDL, category within the Page, outside the datalist.

When the category is changed within the page, I need to retrieve the selectedvalue of Source and if it's 1 or 4, update the PremiumType or, if it's 2 or 3, update the SourcePolicyRef based on the new category.

This is what I have:-
The DDL called when the category is changed.

Code:

    Sub ddl_change_category(ByVal s As Object, ByVal e As EventArgs)
        change_category(ddl_category.SelectedValue)
        build_premiumtype(ddl_category.SelectedValue, ddl_premiumtype)
    End Sub
 
    Sub change_category(ByVal category)
'there is some more code here that just handles controls within the page
.
.
.
            For Each item As DataListItem In dlst_premiums.Items
                If item.ItemType = ListItemType.Item Or item.ItemType = ListItemType.AlternatingItem Or item.ItemType = ListItemType.Footer Then
                    Dim ddl_source As DropDownList = item.FindControl("ddl_source")
                    Select Case ddl_source.SelectedValue
                        Case 1, 4
                            Dim ddl_premiumtype As DropDownList = item.FindControl("ddl_premiumtype")
                            'ddl_premiumtype.Items.Clear()
                            If Not String.IsNullOrEmpty(category) Then
                                build_premiumtype(category, ddl_premiumtype)
                            End If
                        Case 2, 3
                            Dim ddl_transfer As DropDownList = item.FindControl("ddl_transfer")
                            ddl_transfer.Items.Clear()
                            build_premium_transfer(ddl_transfer)
                    End Select
                End If
            Next
    End Sub

The page controls are updated fine, but the DDLs inside the DataList don't get updated. I don't get any errors and I think my logic is correct, but nothing happens.

Can anyone see where I'm going wrong?

Typical, isn't it....I've been going through this code for hours trying to work this out..The second I post it on the forum, I find out the problem.

My build_premiumtype routine had a mistake in it that only occurred in this instance and hadn't occurred before...

Fixed it now...

OK. It's still not 100% right.

In the FooterTemplate of the Datalist I have the same dropdowns that allow you to add a New Premium to the list.

When I change the category and the footer is visible, I need to relevant DDLs updated, but they're not changing. As you can see I include the FooterItem type in my If statement but nothing happens to the footer:-

Code:

    For Each item As DataListItem In dlst_premiums.Items
                If item.ItemType = ListItemType.Item Or item.ItemType = ListItemType.AlternatingItem Or item.ItemType = ListItemType.Footer Then
                    Dim ddl_source As DropDownList = item.FindControl("ddl_source")
                    Select Case ddl_source.SelectedValue
                        Case 1, 4
                            Dim ddl_premiumtype As DropDownList = item.FindControl("ddl_premiumtype")
                            'ddl_premiumtype.Items.Clear()
                            If Not String.IsNullOrEmpty(category) Then
                                build_premiumtype(category, ddl_premiumtype)
                            End If
                        Case 2, 3
                            Dim ddl_transfer As DropDownList = item.FindControl("ddl_transfer")
                            ddl_transfer.Items.Clear()
                            build_premium_transfer(ddl_transfer)
                    End Select
                End If
            Next
    End Sub

Does the footer not get included in DataList.Items collection?