jQuery Swiper script to run after Ng-Repeat elemen

问题:

I'm making a web app using AngularJS, jQuery, HTML, CSS and Bootstrap, and I would like to pick some image links from my JSON that is located in an Apache2 server and use them in order to render those images in my main page. I would also like to swipe them like in a carousel. To make that work, I'm trying to use iDangero.us Swiper.

When I pick my images with 3 separated divs, I have no problems. I get my images and then I can normally swipe them as I want. I do it like shown below:

Main.html:

<div ng-init="initGetRequestMain()">

  <div class="swiper-slide" ng-click="swipers()" 
              style="{{data.background1}}"></div>
  <div class="swiper-slide" ng-click="swipers()" 
              style="{{data.background2}}"></div>
  <div class="swiper-slide" ng-click="swipers()" 
              style="{{data.background3}}"></div>

   <script src="scripts/custom/main/swipers.js"></script>
</div>

I use Swiper to swipe from one image to another, and it seems to work as it should. It's a jQuery plugin, and you can see some demos at this link.

Swipers.js:

angular.module('swipers', [])
       .controller('',[ 
        $(document).ready(function (){
           var swiper = new Swiper('.swiper-container',{
           direction: 'horizontal',
           pagination: '.swiper-pagination',
           paginationClickable: true
       })
})]);

Json:

"background1":"background-image: url(images/img1.jpg)",
"background2":"background-image: url(images/img2.jpg)",
"background3":"background-image: url(images/img3.jpg)"

mainController.js:

  myApp.controller('MainController', ["$scope","$http",                
                  function($scope,$http){

      $scope.initGetRequestMain = function(){

       $http.get('http://localhost/main.json').success(function(data){

         $scope.data=data;
       })
      }
  }]);

The problem is that when I try to use ng-repeat instead of 3 separated divs, I can't see them anymore and my Swiper script triggers before they are fully loaded. I have no errors in my console or in my JSON (validated with JSONLint). Below, I added 2 screenshots of my output in both situations.

Working with 3 separated divs:

Not working with ng-repeat:

This is the code where I try to make ng-repeat work keeping the same controller and the same Swiper script as before:

Main.html:

  <div ng-init="initGetRequestMain()">

       <div ng-repeat="slide in data.slides" isLoaded="">
           <div class="swiper-slide" style="{{slide.background}}" 
                       ng-click="swipers()"></div>
       </div>

    <script type="text/javascript-lazy" src="scripts/custom/main/swipers.js"></script>
  </div>

mainJson.json:

"slides":[
            {"background":"background-image:url('images/img1.jpg')"},
            {"background":"background-image:url('images/img2.jpg')"},
            {"background":"background-image: url('images/img3.jpg')"}
],

In order to get my images loaded before triggering the script, I'm trying to use 2 custom directives.

isLoaded tells me when the last ng-repeat element is loaded and sets pageIsLoaded = true;:

myApp.directive('isLoaded', function (){

   return{
     scope:true,
     restrict: 'A', //Attribute type
     link: function (scope, elements, arguments){ 

        if (scope.$last === true) {
            scope.pageIsReady = true;
            console.log('page Is Ready!');
         }
     }   
   }
})

gettingTheScript waits for pageIsLoaded = true; and loads the script:

myApp.directive('src', function (){

     return{
       scope:true,
       restrict: 'A', //Attribute type
       link: function (scope, elements, arguments){

            scope.$on(pageIsReady===true, function(){
                   if (attr.type === 'text/javascript-lazy'){

                       scope.scriptLink = arguments.src;
                    }
             })
         },
         replace: true, //replaces our element 
         template: '{{scriptLink}}'
       }
  })   

They do not seem to fix my problem. I also can't see console.log('page Is Ready!'); when making the first one.

I'm just having some troubles when I have to trigger a script like Swiper after the page is loaded in order to avoid these kind of problems. My images seem to have no height. I think that the problem is caused by ng-repeat not fully loading before triggering my script.

What am I doing wrong? Are there better solutions?

回答1:

Before getting into how to make this work, most of these types of jQuery plugins don't work well with angular since they make modifications to the DOM that angular doesn't know about.

That being said, the trick is deferring the invocation of the jQuery plugin until after Angular has rendered the DOM.

First, put your swiper plugin into a directive:

.directive('swiper', function($timeout) {
    return {
        link: function(scope, element, attr) {
            //Option 1 - on ng-repeat change notification
            scope.$on('content-changed', function() {
                new Swiper(element , {
                    direction: 'horizontal',
                    pagination: '.swiper-pagination',
                    paginationClickable: true);
            }
            //Option 2 - using $timeout
            $timeout(function(){
                new Swiper(element , {
                    direction: 'horizontal',
                    pagination: '.swiper-pagination',
                    paginationClickable: true);
            });

        }
    };
})

For Option 1, you need a modified isLoaded directive

myApp.directive('isLoaded', function (){

   return{
     scope:false, //don't need a new scope
     restrict: 'A', //Attribute type
     link: function (scope, elements, arguments){ 

        if (scope.$last) {
            scope.$emit('content-changed');
            console.log('page Is Ready!');
        }
     }   
   }
})

Finally, your markup (note the change from isLoaded to is-loaded....this is probably the reason you weren't seeing the notification).

<div ng-init="initGetRequestMain()" swiper>

   <div ng-repeat="slide in data.slides" is-loaded>
       <div class="swiper-slide" style="{{slide.background}}" 
                   ng-click="swipers()"></div>
   </div>
</div>

As mentioned, most jQuery plugins that do carousel functionality don't handle changes to the DOM (i.e new elements) very well. Even with both options, you may see unexpected things if you change your model after the ng-repeat is first rendered. However, if your model is static, this should work for you. If your model changes, then you might want to search for a more "angular" carousel directive.

回答2:

There's an even easier way you can use that's baked into Swiper.js. When you're initializing the swiper, just set the observer property to true. This will make Swiper watch for changes to your slides, so you won't have to worry about whether it runs before all the slides are added through ng-repeat.

Example:

var galleryTop = new Swiper('.gallery-top', { observer: true });

And from the Swiper documentation on the observer property:

Set to true to enable Mutation Observer on Swiper and its elements. In this case Swiper will be updated (reinitialized) each time if you change its style (like hide/show) or modify its child elements (like adding/removing slides)

回答3:

I'm answering to this old question because some guys asked me to do it and because I want to help other developers with this "funny" problem.

After more than one year, I managed to solve this issue using Promises and Factories.

Essentially, I made a Factory, ItemFactory ensuring to get all the items needed (in this case slides), then, I made another Factory, SwiperFactory, which uses a Promise to trigger that funny guy, swipers(). I called all those factory methods into a MainController, which, after getting the slides and triggering the script, does $scope.apply(); to reflect the changes in the main view.

Main.html:

//MainController known as mainCtrl
<div ng-repeat="slide in mainCtrl.slides">
  <div class="swiper-slide" ng-click="mainCtrl.swipers()"></div>
</div>

MainController.js:

angular
.module('myApp')
.controller('MainController', MainController);

function MainController($scope, ItemFactory, SwiperFactory) {

   var vm    = this;
   //Initializing slides as an empty array
   vm.slides = [];

   /** Gets called as soon as the Controller is called **/
   getData('main.json');

   function getData(path){
      ItemFactory.getItems(path).then( function(response){

        //If response is not empty
        if (response) {
           //Assigning fetched items to vm.items
           vm.slides = response.data;
        }

        //Calling triggerSwiper after we ensured fetching item data
        SwiperFactory.triggerSwiper();

        //Callig $scope.$apply() to reflect correctly the changes in the view
        $scope.$apply();
      })
   };

}

ItemFactory.js:

angular
.module('myApp')
.factory('ItemFactory', function ($http) {

    /** Using this referring as ItemFactory Controller **/
    var vm     = this;
    vm.API_URL = 'http://localhost/';

    /** Gets items from API based on jsonPath **/
    function getItems(jsonPath) {
        return $http.get(vm.API_URL + jsonPath
        ).then(function (response) {
            return (response);
        });
    }

    //Exposing getItems method
    return {
        getItems : getItems
    }
});

SwiperFactory.js:

angular
.module('myApp')
.factory('SwiperFactory', function () {

    /** Using this referring as SwiperFactory Controller **/
    var vm     = this;

    /** Triggers Swiper Script 
     *  Resolving only after swiper has been triggered **/
    function triggerSwiper(){
      return new Promise( function(resolve, reject){
        resolve({
            $(document).ready(function (){
                var swiper = new Swiper('.swiper-container',{
                direction           : 'horizontal',
                pagination          : '.swiper-pagination',
                paginationClickable : true
            })
        });

      }, function(error){
         console.log('Error while triggering Swiper');
      })

    }

    //Exposing triggerSwiper method
    return {
        triggerSwiper : triggerSwiper
    }
});

• $scope.$apply(); can be removed, it is not really essential
• In general, this kind of approach works well with asynchronous tasks

The code above does the work, but, please, pay attention to what I'm saying below

Try avoiding using jQuery libraries such as iDangero.us Swiper in an AngularJS project. Instead, look for an Angular library which makes the same work. If back then I was skilled like I'm right now, I would have never used it, expecially for the $(document).ready stuff. Instead, study Promises or AngularJS way of doing that. I was totally new to AngularJS and Web Development in general, so I took wrong decisions.

I hope I've been helpful.