Autopostback and validation

[Fit2Page]

Hi,

 

Is there an example available of how to validate the raddropdowntree in combination with AutoPostback = true?

 

TIA, Marc

[Rumen]

Hi Marc,

Please check the following live demo: Validation, which shows how to validate RadDropDownTree by the use of an asp:CustomValidator. In this case the page could be submitted only if something, that will change the default value of the control, is chosen from the RadDropDownTree. The validatePage() function attached to the ClientValidationFunction validator event checks the count of the entries collection of the DropDownTree and if it is 0, sets the args.IsValid to false.

The DropDownTree also works with all of the standard ASP.NET validators.

Regards,
Rumen
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[konnyaku]

Unrelated, but its regarding the sample given. When I postback the form. how do I get which nodes is checked from the server side?

[Rumen]

Hi Konnyaku,

For all checked nodes are created entries, which you can access in the Entries server collection of the control and get the needed information. Please also check and use the following server events.

Best regards,
Rumen
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[konnyaku]

Thank you for your reply. My design is quite different.

For each RadDropDownTree entries, I enable the checkbox.

When I click Submit button, I want to see which entry has been checked.

Is this possible to do using RadDropDownTree?

[Rumen]

Hello Konnyaku,

You can obtain the entries client side by getting reference to the DropDownTree client-side object

var ddt = $find("ctl00_ContentPlaceholder1_RadDropDownTree1");

and get_entries() method, which returns the RadDropDownTree Entries collection:

ddt.get_entries()._array[0].get_text();
ddt.get_entries()._array[0].get_value();

Please see the attached image for more information.

Regards,
Rumen
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[konnyaku]

Thank you for the quick reply.

Since the design involved postback, is there a way to check on the server side instead of client side?

[Rumen]

Hi,

Check this article: Accessing the Embedded Tree - by having a reference to the treeview control you can use its server API to see which nodes are selected > 

RadDropDownTree1.EmbeddedTree.Nodes[0].Checked

Regards,
Rumen
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[konnyaku]

I tested like this, not on Page_Load, but upon button click:

        For Each tree As RadTreeNode In RadDropDownTree1.EmbeddedTree.Nodes
            MsgBox(tree.Text + " " + tree.Checked.ToString())
        Next

It did not capture the checked/unchecked state of the RadDropDownTree1

[Rumen]

Hello,

My advice is to make it working for a Button Click and after that in the page events:

ASPX

<telerik:RadDropDownTree RenderMode="Lightweight" ID="RadDropDownTree1" runat="server" Width="300px" CheckBoxes="SingleCheck"
                DefaultMessage="Please select" DataFieldID="EmployeeID" DataFieldParentID="ReportsTo" OnNodeDataBound="RadDropDownTree1_NodeDataBound"
                DataTextField="LastName" DataSourceID="SqlDataSource1">
                <DropDownSettings OpenDropDownOnLoad="true" />
            </telerik:RadDropDownTree>
<asp:Button Text="ShowCheckedItems" runat="server" OnClick="Unnamed_Click" />
<asp:TextBox TextMode="MultiLine" Width="200px" Height="200px" runat="server" ID="MultiBox1"></asp:TextBox>

Codebehind:

Protected Sub Unnamed_Click(ByVal sender As Object, ByVal e As EventArgs)
    For Each node As RadTreeNode In RadDropDownTree1.EmbeddedTree.Nodes

        If node.GetAllNodes().Count <> 0 Then

            For Each subnode As RadTreeNode In node.GetAllNodes()
                checkedNode += subnode.Text & " " + subnode.Checked.ToString() & vbLf
                MultiBox1.Text = checkedNode
            Next
        End If
    Next
End Sub

Regards,
Rumen
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[konnyaku]

Tried, but the subnode.Checked.ToString() value is never True.

[Rumen]

On my side the solution works as expected. For your convenience I have attached my test files and a video demo.

Best Regards,
Rumen
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