admin管理员组

文章数量:1242842

When you write something like:

<img ng-if="image.name != null" ng-src="img/{{ image.name }}_img.png" />

If image.name = null Angular will first add tag and evaluate src. The browser will make http request for img/_img.png wchich doesn't exists. Then angular will remove tag after parsing ngIf directive. What is the simplest way to resolve this issue? I thought that it's perfect use case for ngSrc and ngIf.

EDIT

In current unstable 1.2.0-rc.2 issue is fixed and everything works how it is supposed to do. In current stable 1.0.8 you can't even use ternary operator.

When you write something like:

<img ng-if="image.name != null" ng-src="img/{{ image.name }}_img.png" />

If image.name = null Angular will first add tag and evaluate src. The browser will make http request for img/_img.png wchich doesn't exists. Then angular will remove tag after parsing ngIf directive. What is the simplest way to resolve this issue? I thought that it's perfect use case for ngSrc and ngIf.

EDIT

In current unstable 1.2.0-rc.2 issue is fixed and everything works how it is supposed to do. In current stable 1.0.8 you can't even use ternary operator.

  • javascript
  • angularjs
Share Improve this question edited Sep 19, 2013 at 7:46 p2004a asked Sep 18, 2013 at 15:23 p2004ap2004a 1332 silver badges7 bronze badges 1
  • Make a directive that will check the ng-if and if the name is not null pile the ng-src. I'll try a plunkr if you want – Thomas Pons Commented Sep 18, 2013 at 15:25
Add a ment  | 

2 Answers 2

Reset to default 14

You don't need the ng-if directive for this. Just do a ternary operator test in your expression. Something like

<img ng-src="{{image.name?('img/'+ image.name +'_img.png'):null}}"/>

and it should work. See my plunker http://plnkr.co/edit/BWiGdO?p=preview

You can do it like this with a simple directive.

Here is the HTML : 

<!DOCTYPE html>
<html ng-app="App">

  <head>
    <link rel="stylesheet" href="style.css">
    <script src="http://code.angularjs/1.2.0-rc.2/angular.js"></script>
    <script src="http://code.jquery./jquery-2.0.3.min.js"></script>
    <script src="script.js"></script>
  </head>

  <body ng-controller="MyCtrl">
    <h1>Hello Plunker!</h1>
    <img ng-directive />
  </body>

</html>

Here is the directive with the controller :

angular.module('App', [])
  .controller('MyCtrl', function($scope){
     $scope.image = {name: "myName"};
  });

angular.module('App')
  .directive('ngDirective', function($pile){
    return {
      link: function(scope, element, attrs){
        if(scope.image.name != null){
          $pile($(element).attr('ng-src', 'http://lauterry.github.io/slides-prez-angular/img/angularjs.png'))(scope);
        }
      }
    }
  });

Here is the plete working example : http://plnkr.co/edit/LNgsuX

本文标签： javascriptngSrc is computed before ngIf causing unnecessary http requestStack Overflow

版权声明：本文标题：javascript - ngSrc is computed before ngIf causing unnecessary http request - Stack Overflow 内容由网友自发贡献，该文观点仅代表作者本人， 转载请联系作者并注明出处：http://www.betaflare.com/web/1740087827a2223842.html， 本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌抄袭侵权/违法违规的内容，一经查实，本站将立刻删除。