How to call a method defined in an AngularJS directive?
If you want to use isolated scopes you can pass a control object using bi-directional binding = of a variable from the controller scope. You can also control also several instances of the same directive on a page with the same control object.
angular.module('directiveControlDemo', []).controller('MainCtrl', function($scope) { $scope.focusinControl = {};}).directive('focusin', function factory() { return { restrict: 'E', replace: true, template: '<div>A:{{internalControl}}</div>', scope: { control: '=' }, link: function(scope, element, attrs) { scope.internalControl = scope.control || {}; scope.internalControl.takenTablets = 0; scope.internalControl.takeTablet = function() { scope.internalControl.takenTablets += 1; } } };});<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script><div ng-app="directiveControlDemo"> <div ng-controller="MainCtrl"> <button ng-click="focusinControl.takeTablet()">Call directive function</button> <p> <b>In controller scope:</b> {{focusinControl}} </p> <p> <b>In directive scope:</b> <focusin control="focusinControl"></focusin> </p> <p> <b>Without control object:</b> <focusin></focusin> </p> </div></div>
Assuming that the action button uses the same controller $scope as the directive, just define function updateMap on $scope inside the link function. Your controller can then call that function when the action button is clicked.
<div ng-controller="MyCtrl"> <map></map> <button ng-click="updateMap()">call updateMap()</button></div>app.directive('map', function() { return { restrict: 'E', replace: true, template: '<div></div>', link: function($scope, element, attrs) { $scope.updateMap = function() { alert('inside updateMap()'); } } }});As per @FlorianF's comment, if the directive uses an isolated scope, things are more complicated. Here's one way to make it work: add a set-fn attribute to the map directive which will register the directive function with the controller:
<map set-fn="setDirectiveFn(theDirFn)"></map><button ng-click="directiveFn()">call directive function</button>scope: { setFn: '&' },link: function(scope, element, attrs) { scope.updateMap = function() { alert('inside updateMap()'); } scope.setFn({theDirFn: scope.updateMap});}function MyCtrl($scope) { $scope.setDirectiveFn = function(directiveFn) { $scope.directiveFn = directiveFn; };}
Although it might be tempting to expose an object on the isolated scope of a directive to facilitate communicating with it, doing can lead to confusing "spaghetti" code, especially if you need to chain this communication through a couple levels (controller, to directive, to nested directive, etc.)
We originally went down this path but after some more research found that it made more sense and resulted in both more maintainable and readable code to expose events and properties that a directive will use for communication via a service then using $watch on that service's properties in the directive or any other controls that would need to react to those changes for communication.
This abstraction works very nicely with AngularJS's dependency injection framework as you can inject the service into any items that need to react to those events. If you look at the Angular.js file, you'll see that the directives in there also use services and $watch in this manner, they don't expose events over the isolated scope.
Lastly, in the case that you need to communicate between directives that are dependent on one another, I would recommend sharing a controller between those directives as the means of communication.
AngularJS's Wiki for Best Practices also mentions this:
Only use .$broadcast(), .$emit() and .$on() for atomic events Events that are relevant globally across the entire app (such as a user authenticating or the app closing). If you want events specific to modules, services or widgets you should consider Services, Directive Controllers, or 3rd Party Libs
- $scope.$watch() should replace the need for events
- Injecting services and calling methods directly is also useful for direct communication
- Directives are able to directly communicate with each other through directive-controllers