AngularJS 1.8: Difficulty propagating scope changes within nested controllers using 'controller as' syntax
I'm updating my dependencies and I've been banging my head against this for hours. This might be a silly question, but I'm relatively new to this, so bear with me. I'm currently working on an AngularJS 1.8 application where I have a nested structure of controllers using the 'controller as' syntax. I'm trying to propagate changes from a child controller back to its parent controller, but it seems that the changes are not reflecting as expected. In the parent controller, I have a property `parentData` that I want to update based on a change in the child controller. Here’s the relevant code for both controllers: ```javascript // Parent Controller app.controller('ParentCtrl', function() { var vm = this; vm.parentData = 'Initial Data'; vm.updateData = function(newData) { vm.parentData = newData; }; }); // Child Controller app.controller('ChildCtrl', function() { var vm = this; vm.childData = 'Child Data'; vm.updateParent = function() { // Trying to access parent's updateData function vm.updateData(vm.childData); }; }); ``` In my HTML, I’ve set it up like this: ```html <div ng-controller="ParentCtrl as parent"> <p>{{ parent.parentData }}</p> <div ng-controller="ChildCtrl as child"> <input ng-model="child.childData" /> <button ng-click="child.updateParent()">Update Parent</button> </div> </div> ``` When I click the button to update the parent’s data, I get an behavior: `TypeError: vm.updateData is not a function`. It seems that the child controller want to access the parent's method. I’ve tried passing the parent controller instance to the child controller during initialization, but it didn’t work. Here's what I attempted: 1. Injecting the parent controller in the child controller: ```javascript app.controller('ChildCtrl', function($scope, ParentCtrl) { var vm = this; vm.childData = 'Child Data'; vm.updateParent = function() { ParentCtrl.updateData(vm.childData); }; }); ``` This resulted in a circular dependency behavior. 2. Using `$scope.$parent` to access the parent scope: ```javascript app.controller('ChildCtrl', function($scope) { var vm = this; vm.childData = 'Child Data'; vm.updateParent = function() { $scope.$parent.updateData(vm.childData); }; }); ``` This did update the data, but it feels like a hack and is not a best practice. How can I properly propagate changes from a nested controller back to the parent controller using the 'controller as' syntax without running into these issues? I'm working on a application that needs to handle this. Am I missing something obvious? Has anyone else encountered this? How would you solve this? My development environment is Linux.