Angularjs: set parent directive scope value with child directive - angularjs

Question

I'm not sure this is the way to do this, but my goal is the following:
I have a parent directive
Inside the parent directive's block, I have a child directive that will get some input from the user
The child directive will set a value in the parent directive's scope
I can take it from there
Of course the problem is that the parent and child directives are siblings. So I don't know how to do this. Note - I do not want to set data in the
Fiddle: http://jsfiddle.net/rrosen326/CZWS4/
html:
<div ng-controller="parentController">
<parent-dir dir-data="display this data">
<child-dir></child-dir>
</parent-dir>
</div>
Javascript
var testapp = angular.module('testapp', []);
testapp.controller('parentController', ['$scope', '$window', function ($scope, $window) {
console.log('parentController scope id = ', $scope.$id);
$scope.ctrl_data = "irrelevant ctrl data";
}]);
testapp.directive('parentDir', function factory() {
return {
restrict: 'ECA',
scope: {
ctrl_data: '#'
},
template: '<div><b>parentDir scope.dirData:</b> {{dirData}} <div class="offset1" ng-transclude></div> </div>',
replace: false,
transclude: true,
link: function (scope, element, attrs) {
scope.dirData = attrs.dirData;
console.log("parent_dir scope: ", scope.$id);
}
};
});
testapp.directive('childDir', function factory() {
return {
restrict: 'ECA',
template: '<h4>Begin child directive</h4><input type="text" ng-model="dirData" /></br><div><b>childDir scope.dirData:</b> {{dirData}}</div>',
replace: false,
transclude: false,
link: function (scope, element, attrs) {
console.log("child_dir scope: ", scope.$id);
scope.dirData = "No, THIS data!"; // default text
}
};
});

Answer 1

If you want that kind of communication, you need to use require in the child directive. That will require the parent controller so you need a controller there with the functionality you want the children directives to use.
For example:
app.directive('parent', function() {
return {
restrict: 'E',
transclude: true,
template: '<div>{{message}}<span ng-transclude></span></div>',
controller: function($scope) {
$scope.message = "Original parent message"
this.setMessage = function(message) {
$scope.message = message;
}
}
}
});
The controller has a message in the $scope and you have a method to change it.
Why one in $scope and one using this? You can't access the $scope in the child directive, so you need to use this in the function so your child directive will be able to call it.
app.directive('child', function($timeout) {
return {
restrict: 'E',
require: '^parent',
link: function(scope, elem, attrs, parentCtrl) {
$timeout(function() {
parentCtrl.setMessage('I am the child!')
}, 3000)
}
}
})
As you see, the link receives a fourth param with the parentCtrl (or if there is more than one, an array). Here we just wait 3 seconds until we call that method we defined in the parent controller to change its message.
See it live here: http://plnkr.co/edit/72PjQSOlckGyUQnH7zOA?p=preview

Answer 2

First, watch this video. It explains it all.
Basically, you need to require: '^parentDir' and then it will get passed into your link function:
link: function (scope, element, attrs, ParentCtrl) {
ParentCtrl.$scope.something = '';
}