Only allow expressions to be added to groups

Hello, Ole,

If I understand your requirement correctly you would like to remove the group option from the RadDataFilter control and allow only expressions. To achieve this you can use the following approach:

this.radDataFilter1.NodeFormatting += this.RadDataFilter1_NodeFormatting;
private void RadDataFilter1_NodeFormatting(object sender, TreeNodeFormattingEventArgs e)
{
    DataFilterAddNodeElement addNodeElement = e.NodeElement as DataFilterAddNodeElement;
    if (addNodeElement != null)
    {
        var dropDownButton = addNodeElement.DropDownButton;
        if (dropDownButton.Items.Count == 2)
        {
            dropDownButton.Items.RemoveAt(0);
        }
    }
}

I hope this helps. Let me know if you have any other questions.

Regards,
Nadya
Progress Telerik

Thanks Nadya,

How can I tell if the DataFilterAddNodeElement is from the DataFilterRootNode or from a DataFilterGroupElement?

Thanks

Hello, Ole,

If you disable the Group option in RadDataFilter control you won't be able to add groups. Hence, you wouldn't be able to have nested groups as well. If you have added just Expressions they will appear as root nodes in the tree, without nested groups. Please see the attached gif file. Am I missing something? In case you have a different set up it would be greatly appreciated if you can provide more information about what is the exact current implementation that you have. A picture or video would be much appreciated.

Looking forward to your reply.

Regards,
Nadya
Progress Telerik

Hello Nadya, 

I have attached a picture that will hopefully help explain the result I'm after. I still want to be able to add groups, but only to the root node and not to other groups. In my attached picture, I want to prevent the node with the red arrow from being added. I still want to allow expressions to be added to group nodes, just not group nodes to other group nodes.

Hopefully this helps.

Thank you,

Ole

Hello, Ole,

Thank you for the picture and clarifying that you want to be able to add groups but only to the root nodes. Please refer to the following code snippet that demonstrates how you can achieve this:

private void RadDataFilter1_NodeFormatting(object sender, TreeNodeFormattingEventArgs e)
{
    DataFilterAddNodeElement addNodeElement = e.NodeElement as DataFilterAddNodeElement;
    if (addNodeElement != null)
    {
        if (e.Node.Level > 1)
        {
            var dropDownButton = addNodeElement.DropDownButton;
            if (dropDownButton.Items.Count == 2)
            {
                dropDownButton.Items.RemoveAt(0);
            }
        }
    }
}

I hope this helps. Should you have any other questions do not hesitate to ask.

Regards,
Nadya
Progress Telerik

That worked perfectly! Thank you Nadya!