Confusion with Coredata and Bindings

[zer0]

Hi,

I have created a project to teach my self coredata. At the moment I have a simple data model containing 2 entity's called Skill and SkillAction with a one to many relationship (Skill 1-* SkillAction (inversed)). Now the confusion starts with the bindings,

I have bound the two entity's to two array controllers, that bit works i have a pop up button that display's the skill names and a detail view bellow containing a table view, set to display the skill's skill actions of the selected skill, at the moment the columns are bound to skillActions.arragendObjects.reqLvl etc.

How does it know what the selected Skill is? my pop up button's bindings are only set to content and content values.

And I have my SkillActions array controller's content set bound to Skills.selection.skillActions

Now I can run this with no problems but when i select a skill and try and create a skillAction nothing happens, I have a button that is set to the add: target of the SkillActions array controller.

I am really confused on why it's not working, kinda using this tutorial as reference but not suited to my program

[zer0]

Anyone? or how would you do some thing similar with two entity's with the 1st being a master and the other entity being a detail in the GUI?