Hide SubGrid '+' / New Button button based on Parent status

Hide child  records sub grid + or Add New button

Some time we need to hide  '+' button or Add New button for child record grid..

You can do this by adding enable rule for + or Add New Button.

1. Open Child record customization in Ribbon workbench

2.  Select Entity so that we will able to modify command definition.

3. In Sub Gird, select + Add New {0} Button, right click and select Customize Command

4.  Add New Enable Rule

5. For Enable Rule.. Add steps, and select Custom JavaScript Rule

6. Set Custom rule properties as 

Default : true

Function Name: DisableSubGridNewButton

Invert Result : False

Library: JavaScript web resource where you added DisableSubGridNewButton function 

Parameters : None. 

JavaScript DisableSubGridNewButton Function 

-- When Form is ready only then hide +new or Add new Button for child records.

function DisableSubGridNewButton() {

    if (Xrm.Page.ui.getFormType() == 3) // Read Only

        return false;

    else

        return true;

}

-- based on Some values on Form

function DisableSubGridNewButton() {

    var IsMarried = Xrm.Page.getAttribute('new_status').getValue();

    if (IsMarried == 70000001) //un marriged

        return false;  // Hide button

    else

        return true;  //Show button

}

7. Add this enable rule to button Command

8. Save and Publish Customization.