I was looking into my options for using the functionality you explain here but your last example (#5) did not work for me.
I was able to get my directives to work with both a require on the parent directive and the current child directive. Here is an explanation on a stackoverflow question I answered ( http://stackoverflow.com/questions/21342698/controller-required-by-directive-cant-be-found/ ) and here is my functioning example on github ( https://github.com/sgwatgit/angular-directives-communication )
I was looking into my options for using the functionality you explain here but your last example (#5) did not work for me.
I was able to get my directives to work with both a require on the parent directive and the current child directive. Here is an explanation on a stackoverflow question I answered ( http://stackoverflow.com/questions/21342698/controller-required-by-directive-cant-be-found/ ) and here is my functioning example on github ( https://github.com/sgwatgit/angular-directives-communication )