Hide or Show LOV Based on LOV RowSet Size

If you were ever wondering, how to show or hide LOV component dynamically, depending if there are values in LOV or if it is empty - I will describe it in this post. Sample application contains Departments LOV VO with View Criteria and Bind Variable to filter based on Manager ID:

LOV is defined for Department ID attribute, it will be rendered as Choice List and displays Department Name:

This LOV is filtered through View Accessor, it provides current Employee ID for filtering. This means, LOV will bring all such departments, where current employee is a manager:

According our requirement, we want to show Department ID attribute, only if associated LOV contains values. This can be achieved by declaring custom method inside View Object Row Implementation class and exposing this method through Client Row Interface into Data Control:

This custom method is not doing anything, except it checking Estimated Row Count for Departments LOV View Accessor. Its how we can check if our Choice List contains any values (if current employee manages any departments):

This method is exposed through Data Control and is accessible from Page Definition:

I would recommend not to call custom Data Control method directly from ADF Rich Faces component, instead create accessor method in managed bean and call it from there through bindings layer:

ADF Rich Faces component should reference bean accessor method for boolean type:

Department ID Choice List is shown for Employee ID = 108, this employee is a manager for Department  = Finance:

Another employee, is not a manager and Department ID Choice List becomes hidden automatically:

Download sample application - ChoiceListRendering.zip