Using ES6 Classes as Angular 1.x directives
JavascriptAngularjsClassAngularjs DirectiveEcmascript 6Javascript Problem Overview
I'm doing a small project to play around the goody bag the ES6 is bringing, I'm trying to set register a class as an angular directive, but I'm running into this error "TypeError: Cannot call a class as a function", but from the examples I'm finding they just write the class and register it with angular as a directive. Here's my directive.
class dateBlock {
constructor () {
this.template = '/app/dateblock/dateblock.html';
this.restrict = 'AE';
this.scope = {};
}
};
export default dateBlock
and my index where I import it and then declare it.
import calendarController from './calendar/calendar.js'
import dateBlock from './dateblock/dateblock.js'
function setup($stateProvider) {
$stateProvider
.state('base', {
url: '',
controller: calendarController,
templateUrl: '/app/calendar/calendar.html'
});
};
setup.$inject = ['$stateProvider']
var app = angular.module('calApp',['ngAnimate','ui.router','hmTouchEvents', 'templates'])
.config(setup)
.controller('calendarController', calendarController)
.directive('dateBlock', dateBlock)
If I missed some crucial step I'd love to hear it. Also side question is it cleaner to import all the apps components to the index and register them all there or export the app and import and register within the components?
Javascript Solutions
Solution 1 - Javascript
From my point of view, there is no need to use external libraries like register.js, because you can create directive as a ES6 class in this way:
class MessagesDirective {
constructor() {
this.restrict = 'E'
this.templateUrl = 'messages.html'
this.scope = {}
}
controller($scope, $state, MessagesService) {
$scope.state = $state;
$scope.service = MessagesService;
}
link(scope, element, attrs) {
console.log('state', scope.state)
console.log('service', scope.service)
}
}
angular.module('messages').directive('messagesWidget', () => new MessagesDirective)
Using directive controller allows you to inject dependencies, even without additional declaration (ex. MessagesDirective.$inject = ['$scope', '$state', 'MessagesService']
), so you can use services in link function via scope if you need.
Solution 2 - Javascript
As mentioned in a comment, the module.directive()
method expects a factory function rather than a constructor.
The most simple way would be to wrap your class in a function that returns an instance:
angular.module('app')
.directive('dateBlock', () => new DateBlock());
However, this will only work in the most limited sense - it does not allow for dependency injection and the compile
and link
functions of your directive (if defined) will not work as expected.
In fact, this is a problem I have looked into quite extensively and it turned out to be fairly tricky to solve (for me at least).
I wrote an extensive article covering my solution, but as far as you are concerned I can point you to the discussion of the two main issues that need to be resolved:
-
Dynamically converting a class definition into an angular-compatible factory function
-
Allowing a directive's
link
andcompile
functions to be defined as class methods
The full solution involves too much code to paste here, I think, but I have put together a working demo project which allows you to define a directive as an ES6 class like this:
class MyDirective {
/*@ngInject*/
constructor($interval) {
this.template = '<div>I\'m a directive!</div>';
this.restrict = 'E';
this.scope = {}
// etc. for the usual config options
// allows us to use the injected dependencies
// elsewhere in the directive (e.g. compile or link function)
this.$interval = $interval;
}
// optional compile function
compile(tElement) {
tElement.css('position', 'absolute');
}
// optional link function
link(scope, element) {
this.$interval(() => this.move(element), 1000);
}
move(element) {
element.css('left', (Math.random() * 500) + 'px');
element.css('top', (Math.random() * 500) + 'px');
}
}
// `register` is a helper method that hides all the complex magic that is needed to make this work.
register('app').directive('myDirective', MyDirective);
Check out the demo repo here and here is the code behind register.directive()
Solution 3 - Javascript
@Michael is right on the money:
> the module.directive() method expects a factory function
However I solved it using another technique, a little cleaner I suppose, It works fine for me, it's not perfect though... I defined a static method that returns a the factory expected by module()
class VineDirective {
constructor($q) {
this.restrict = 'AE';
this.$q = $q;
}
link(scope, element, attributes) {
console.log("directive link");
}
static directiveFactory($q){
VineDirective.instance = new VineDirective($q);
return VineDirective.instance;
}
}
VineDirective.directiveFactory.$inject = ['$q'];
export { VineDirective }
And in my app I do:
angular.module('vineyard',[]).directive('vineScroller', VineDirective.directiveFactory)
I believe there's no other way to use classes + directives that going through hacks like this at this point, just pick the easy one ;-)
Solution 4 - Javascript
A simpler, cleaner and more readable solution .
class ClipBoardText {
constructor() {
console.log('constructor');
this.restrict = 'A';
this.controller = ClipBoardTextController;
}
link(scope, element, attr, ctr) {
console.log('ctr', ctr);
console.log('ZeroClipboard in link', ctr.ZeroClipboard);
console.log('q in link', ctr.q);
}
static directiveFactory() {
return new ClipBoardText();
}
}
// do not $inject like this
// ClipBoardText.$inject = ['$q'];
class ClipBoardTextController {
constructor(q) {
this.q = q;
this.ZeroClipboard = 'zeroclipboard';
}
}
ClipBoardTextController.$inject = ['$q'];
export default ClipBoardText.directiveFactory;
You cannot get $q
in link
function, this
in link
will be undefined
or null
. exploring-es6-classes-in-angularjs-1-x#_section-factories
> when Angular invokes the link function, it is no longer in the context of the class instance, and therefore this.$interval will be undefined
So make use of the controller
function in the directive, and inject dependencies or anything that you want to access in the link
function.
Solution 5 - Javascript
My solution:
class myDirective {
constructor( $timeout, $http ) {
this.restrict = 'E';
this.scope = {};
this.$timeout = $timeout;
this.$http = $http;
}
link() {
console.log('link myDirective');
}
static create() {
return new myDirective(...arguments);
}
}
myDirective.create.$inject = ['$timeout', '$http'];
export { myDirective }
and in the main app file
app.directive('myDirective', myDirective.create)
Solution 6 - Javascript
In my project I use a syntax sugar for injections. And ES6 makes it pretty simple to use injectable factories for directives avoiding too much duplicate code. This code allows injection inheritance, uses annotated injections and so on. Check this:
First step
Declare base class for all angular controllers\directives\services - InjectableClient. Its main task - set all injected params as properties for 'this'. This behavior can be overridden, see examples below.
class InjectionClient {
constructor(...injected) {
/* As we can append injections in descendants we have to process only injections passed directly to current constructor */
var injectLength = this.constructor.$inject.length;
var injectedLength = injected.length;
var startIndex = injectLength - injectedLength;
for (var i = startIndex; i < injectLength; i++) {
var injectName = this.constructor.$inject[i];
var inject = injected[i - startIndex];
this[injectName] = inject;
}
}
static inject(...injected) {
if (!this.$inject) {
this.$inject = injected;
} else {
this.$inject = injected.concat(this.$inject);
}
};
}
For example, if we call SomeClassInheritedFromInjectableClient.inject('$scope'), in directive or controller we will use it as 'this.$scope'
Second step
Declare the base class for directive with static method "factory()", which binds $injected property of directive class to factory function. And also "compile()" method, which binds the context of link function to the directive itself. Its allows to use our injected values inside the link function as this.myInjectedService.
class Directive extends InjectionClient {
compile() {
return this.link.bind(this);
}
static factory() {
var factoryFunc = (...injected) => {
return new this(...injected);
}
factoryFunc.$inject = this.$inject;
return factoryFunc;
}
}
Third step
Now we can declare as much directive classes as possible. With inheritance. And we can set up injections in simple way with spread arrays (just dont forget call super method). See examples:
class DirectiveFirst extends Directive {
}
DirectiveFirst.inject('injA', 'injB', 'injC');
class DirectiveSecond extends DirectiveFirst {
constructor(injD, ...injected) {
super(...injected);
this.otherInjectedProperty = injD;
}
}
// See appended injection does not hurt the ancestor class
DirectiveSecond.inject('injD');
class DirectiveThird extends DirectiveSecond {
constructor(...injected) {
// Do not forget call the super method in overridden constructors
super(...injected);
}
}
The last step
Now register directives with angular in simple way:
angular.directive('directiveFirst', DirectiveFirst.factory());
angular.directive('directiveSecond', DirectiveSecond.factory());
angular.directive('directiveThird', DirectiveThird.factory());
Now test the code:
var factoryFirst = DirectiveFirst.factory();
var factorySec = DirectiveSecond.factory();
var factoryThird = DirectiveThird.factory();
var directive = factoryFirst('A', 'B', 'C');
console.log(directive.constructor.name + ' ' + JSON.stringify(directive));
directive = factorySec('D', 'A', 'B', 'C');
console.log(directive.constructor.name + ' ' + JSON.stringify(directive));
directive = factoryThird('D', 'A', 'B', 'C');
console.log(directive.constructor.name + ' ' + JSON.stringify(directive));
This will return:
DirectiveFirst {"injA":"A","injB":"B","injC":"C"}
DirectiveSecond {"injA":"A","injB":"B","injC":"C","otherInjectedProperty":"D"}
DirectiveThird {"injA":"A","injB":"B","injC":"C","otherInjectedProperty":"D"}
Solution 7 - Javascript
class ToggleShortcut{
constructor($timeout, authService, $compile, $state){
var initDomEvents = function ($element, $scope) {
var shortcut_dropdown = $('#shortcut');
$compile(shortcut_dropdown)($scope);
$scope.goToShortCutItem = function(state, params){
var p = params || null;
if(state === 'app.contacts.view'){
var authProfile = authService.profile;
if(authProfile){
p = {
id:authProfile.user_metadata.contact_id
};
}
}
$state.go(state, p);
window.setTimeout(shortcut_buttons_hide, 300);
};
$element.on('click', function () {
if (shortcut_dropdown.is(":visible")) {
shortcut_buttons_hide();
} else {
shortcut_buttons_show();
}
});
// SHORTCUT buttons goes away if mouse is clicked outside of the area
$(document).mouseup(function (e) {
if (shortcut_dropdown && !shortcut_dropdown.is(e.target) && shortcut_dropdown.has(e.target).length === 0) {
shortcut_buttons_hide();
}
});
// SHORTCUT ANIMATE HIDE
function shortcut_buttons_hide() {
shortcut_dropdown.animate({
height: "hide"
}, 300, "easeOutCirc");
$('body').removeClass('shortcut-on');
}
// SHORTCUT ANIMATE SHOW
function shortcut_buttons_show() {
shortcut_dropdown.animate({
height: "show"
}, 200, "easeOutCirc");
$('body').addClass('shortcut-on');
}
};
var link = function($scope, $element){
$timeout(function(){
initDomEvents($element, $scope);
});
};
this.restrict = 'EA';
this.link = link;
}
}
toggleShortcut.$inject = ['$timeout', 'authService', '$compile', '$state'];
function toggleShortcut($timeout, authService, $compile, $state){
return new ToggleShortcut($timeout, authService, $compile, $state);
}
angular.module('app.layout').directive('toggleShortcut', toggleShortcut);
Solution 8 - Javascript
I had a similar problem. But in my case it worked and failed when I deployed to production. And it failed because production has the latest version of 6to5.
This could be prevented by using npm shrinkwrap
.
According to the latest ES6 spec you can't use a class like this. https://github.com/babel/babel/issues/700
Solution 9 - Javascript
I faced the same problem. First time I tried to solve problem via ES6 classes but I have problem with $inject my dependencies. After I realized what angular have couple styles of writing code and I tried. At all I used John Papa styles and I got this works code in my rails app with ES6:
((angular) => {
'use strict';
var Flash = ($timeout) => {
return {
restrict: 'E',
scope: {
messages: '=messages'
},
template: (() => {
return "<div class='alert flash-{{ message[0] }}' ng-repeat = 'message in messages'>" +
"<div class= 'close' ng-click = 'closeMessage($index)' data-dismiss = 'alert' > × </div>" +
"<span class= 'message' >{{ message[1] }}</ span>" +
"</ div>";
}),
link: (scope) => {
scope.closeMessage = (index) => {
scope.messages.splice(index, 1)
};
$timeout(() => {
scope.messages = []
}, 5000);
}
}
};
Flash.$inject = ['$timeout'];
angular.module('Application').directive('ngFlash', Flash);
})(window.angular);
I know that I can do little bit improvements with functions and variables in more ES6 style. I hope it helps.
Solution 10 - Javascript
I ran into this problem just now and I saw this topic. Tried some methods provided in discussion, I finally solved this problem in a very simple way:
export default function archiveTreeDirective() {
'ngInject';
return {
restrict: 'E',
scope: {
selectedNodes: "="
},
templateUrl: 'app/components/directives/archiveTree/archiveTree.html',
controller: ArchiveTreeController,
controllerAs: 'vm',
bindToController: true
};
}
class ArchiveTreeController {
constructor() {
'ngInject';
...
}
...
}
I directly use function as the .directive('directiveName',factory) argument, and export it, later import it in module declaration. But I missed the "default" statement when exporting, so I got an error. After I add "default" key word, everything works!
I find this method also works in my route configs (also in a function way).
============ Hope you can understand my poor English :)