title: Using a Popup button in Master-Detail
body: <p>My Document based, Core Data application (using bindings in IB) has two entities, <strong>Employee</strong> (with an <strong>employeeName</strong> attribute) and <strong>TimeSheet</strong> (with <strong>timeDescription</strong> and <strong>entryDate</strong> attributes).  <strong>Employee</strong> has a one(<strong>employeeDetails</strong>)-to-many(<strong>employeeTimeSheet</strong>) relationship with <strong>TimeSheet</strong>.</p>
  
  <p>I'm constructing a Master-Detail set up for a TimeSheet entry.</p>
  
  <p>For the Master I've got a one column tableView which has it's <strong>value</strong> bound to: <strong>EmployeeController</strong> (an NSArrayController using the Employee entity), <strong>arrangedObjects</strong>, <strong>employeeName</strong>.</p>
  
  <p>I have a detailController (another NSArrayController) which is set up as an NSMutableDictionary which has it's <strong>contentSet</strong> bound to <strong>EmployeeController</strong>, <strong>selection</strong>, <strong>employeeTimeSheet</strong>.</p>
  
  <p>I then have Detail tableView which has three columns, with their respective <strong>value</strong> bound to <strong>DetailController</strong>, <strong>arrangedObjects</strong>, <strong>employeeDetails.employeeName</strong>(column 0),  <strong>entryDate</strong>(column 1) and <strong>timeDescription</strong>(column 2).</p>
  
  <p>Now this all works fine, I can select an Employee from the Master Table and the Detail Table shows all the TimeSheet entries associated with that Employee.  I can add entries using the selected Employee, everything works great.</p>
  
  <p>My problem is, instead of having a tableView as a Master view, I wanted an NSPopupButton in it's place from which I can select an Employee and view all the time entries associated with that Employee.</p>
  
  <p>I've tried every combination of content, value, arrangedObjects, selectedObject(s) etc. with every combination of the controllers I have but cannot get the NSPopupButton to behave in a similar way to the single column tableView.</p>
  
  <p>I've searched in vain for more information on this and read through the bindings documentation several times but just keep getting mixed up.  I feel this should be relatively simple but I just can't seem to get it.  I've been racking my brains for almost two days now before posting on here.</p>
  
  <p>Can anybody point out where I'm going wrong?  I'd post code but that isn't really appropriate seeing it's mainly an IB thing.</p>
  
  <p>Billy.</p>