How to expose directive methods without using $broadcast or '=' between modules?
Using $broadcast (events) if there are multiple directives all will be notified. It cannot return value too.
Exposing directive's function by html attribute I think it is not that best that Angular has to offer.
Angular Bootstrap UI do it using services (I guess): It have a service named "$uibModal". You can call a function "$uibModal.open()" of Modal Directive by injecting $uibModal service.
Is that the right way?
app.service("apiService", function() {
var apiHash = {};
this.addApi = function (name,api) {
apiHash[name] = api;
};
this.removeApi = function (name) {
delete apiHash[name];
};
this.getApi = function (name) {
return apiHash[name];
};
});
app.directive("myDirective", function (apiService) {
return {
restrict: 'E',
scope: {},
template: `<h1>{{title}}</h1>`,
link: postLink
};
function postLink(scope, elem, attrs)
var name = attrs.name || 'myDirective';
var api = {};
api.setTitle = function(value) {
scope.title = value;
};
apiService.addApi(name, api);
scope.$on("$destroy", function() {
apiService.removeApi(name);
});
}
});
Elsewhere in the app, the title of the directive can be set with:
apiService.getApi('myDirective').setTitle("New Title");
Notice that the directive registers the api with a name determined by the name attribute of the directive. To avoid memory leaks, it unregisters itself when the scope is destroyed.
How could I use it from a controller?
app.controller('home', function($scope,apiService) {
$scope.title = "New Title";
$scope.setTitle = function() {
apiService.getApi('mainTitle').setTitle($scope.title);
};
})
<body ng-controller="home">
<my-directive name="mainTitle"></my-directive>
<p>
<input ng-model="title" />
<button ng-click="setTitle()">Set Title
</button>
</p>
</body>
angular.module('myApp', [])
.service("apiService", function() {
var apiHash = {};
this.addApi = function(name, api) {
apiHash[name] = api;
};
this.getApi = function(name) {
return apiHash[name];
};
})
.directive("myDirective", function(apiService) {
return {
restrict: 'E',
scope: {},
template: `<h1>{{title}}</h1>`,
link: postLink
};
function postLink(scope, elem, attrs) {
var name = attrs.name || 'myDirective';
var api = {};
api.setTitle = function(value) {
scope.title = value;
};
apiService.addApi(name, api);
scope.$on("$destroy", function() {
apiService.addApi(name, null);
});
}
})
.controller('home', function($scope,apiService) {
$scope.title = "New Title";
$scope.setTitle = function() {
apiService.getApi('mainTitle').setTitle($scope.title);
};
})<script src="//unpkg.com/angular/angular.js"></script>
<body ng-app="myApp" ng-controller="home">
<my-directive name="mainTitle"></my-directive>
<p>
<input ng-model="title" />
<button ng-click="setTitle()">Set Title
</button>
</p>
</body>.factory('myService', [function() {
return {
charCount: function(inputString) {
return inputString.length;
}
}
}])
this service exposes function charCount(); in your directive you have to inject it like this
.directive('testDirective', ['myService', function(myService) {
return {
restrict: 'A',
replace: true,
template: "<div>'{{myTestString}}' has length {{strLen}}</div>",
link: function($scope, el, attrs) {
$scope.myTestString = 'string of length 19';
$scope.strLen = myService.charCount( $scope.myTestString );
}
}
}])
and, of course call it
$scope.strLen = myService.charCount( $scope.myTestString );
<html>
<style>
#out {
width:96%;
height:25%;
padding:10px;
border:3px dashed blue;
font-family: monospace;
font-size: 15px;
}
</style>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.6/angular.min.js"></script>
<script>
var APP = angular.module('MYAPP', []);
APP.controller('main', ['$scope', '$element', '$compile', 'myService', function($scope, $element, $compile, myService) {
$scope.test = 'my Test Controller';
$scope.directiveTest = "directive test";
var testSvc = myService.charCount($scope.test);
$scope.showTestDir = true;
}])
.directive('testDirective', ['myService', function(myService) {
return {
restrict: 'A',
replace: true,
template: "<div>'{{myTestString}}' has length {{strLen}}</div>",
link: function($scope, el, attrs) {
$scope.myTestString = 'string of length 19';
$scope.strLen = myService.charCount( $scope.myTestString );
}
}
}])
.factory('myService', [function() {
return {
charCount: function(inputString) {
return inputString.length;
}
}
}])
.filter('toUpper', function() {
return function(input) {
return input.toUpperCase();
}
})
.filter('toLower', function() {
return function(input) {
return input.toLowerCase();
}
})
;
</script>
<body ng-app="MYAPP">
<div id="out" ng-controller="main">
{{test}} - not filtered
<br/>
{{test|toUpper}} - filtered toUpper
<br/>
{{test|toLower}} - filtered toLower
<br/>
<br/>
<div test-directive ng-if="showTestDir"></div>
</div>
</body>
</html>
ng-refdirective. Theng-refattribute tells AngularJS to publish the controller of a component on the current scope. This is useful for having a component such as an audio player expose its API to sibling components. Its play and stop controls can be easily accessed. For more information, see How to expose behavior from a directive with isolated scope?. – georgeawg