AngularJS中ng-repeat渲染完成事件和中间变量的引用

旧城等待， 2022-09-26 02:43 173阅读 0赞

## ng-repeat渲染完成事件 ##

因为在用AngularJS期间, 经常用到ng-repeat, 而有时需要在其渲染完成时操作已经渲染的对象, 所以特在此记录一下添加渲染事件的方法, 以方便以后的使用;

代码如下

myApp.directive('onRepeatFinishedRender', function ($timeout) { return { restrict: 'A', link: function (scope, element, attr) { if (scope.$last === true) { $timeout(function () { //这里element, 就是ng-repeat渲染的最后一个元素 scope.$emit('ngRepeatFinished', element); }); } } }; });

这其实是一个指令, 像使用一般指令一样使用就行了, 因为这里设置restrict为"A", 所以只能作为属性插入, 另外, 向回调函数传入element元素, 是为了方便区分多个使用此指令的元素, 比如有两个地方使用, 代码如下

<ul repeat-id="r1">
      <li ng-repeat="p in persons track by $index" on-repeat-finished-render>{
       {p}}</li>
    </ul>
    <ul repeat-id="r2">
      <li ng-repeat="a in animates track by $index" on-repeat-finished-render>{
       {a}}</li>
    </ul>
    <script> myApp.controller('userCtrl', function ($scope) { $scope.$on("ngRepeatFinished", function (repeatFinishedEvent, element){ var repeatId = element.parent().attr("repeat-id"); switch (repeatId){ case "r1": //repeat-id为r1的ul, repeat渲染完成 break; case "r2": //repeat-id为r2的ul, repeat渲染完成 break; } }) }); </script>

## 中间变量的引用 ##

另外还有一个要用到的, 就是在用filter等的时候, 有时需要用一个中间变量引用filter后的数组, 方便在html中使用, 比如, 我需要在将persons中的数据, 按照'sort'属性排列, 并且需要在repeat元素内需要访问排序后的数组, 可以这么做

<ul>
      <li ng-repeat="p in ps=(persons|orderBy:'sort') track by $index" ng-click="upOne(ps, index, $first)">{
       {p.name}}</li>
    </ul>
    <script> myApp.controller('userCtrl', function ($scope) { //这里传过来就是排序后的数组 //此函数的作用就是, 点击元素后, 将当前点击的元素和其上面的元素交换位置 $scope.upOne = function (arr, index, first){ if(!first){ var tmp = arr[index].sort; arr[index].sort = arr[index-1].sort; arr[index-1].sort = tmp; } } }); </script>

## 综合实例 ##

下面是一个完整的例子[点击下载][Link 1], 可以通过点击右侧按钮, 进行上移或下移进行排序, 大家可以测试一下

<!DOCTYPE html>
    <html>
      <head>
        <meta charset="UTF-8">
        <script src="http://apps.bdimg.com/libs/angular.js/1.3.9/angular.min.js"></script>
        <style> table{ width:600px; margin: auto; border: none; border-padding:0; border-spacing: 0;} table td{ text-align: center;} table td .button{ cursor: pointer; color: #571d00; font-weight: bold;} table tr{ height: 2.5em; vertical-align: middle;} table tbody tr:nth-child(2n+1){background-color: #f0f0f0;} table tbody tr:nth-child(2n){background-color: #f0e0ff;} </style>
      </head>
      <body ng-app="myApp" ng-controller="userCtrl">
        <table>
          <thead>
            <tr>
              <th>索引</th><th>学号</th><th>姓名</th><th>性别</th><th>年龄</th><th>操作</th>
            </tr>
          </thead>
          <tbody repeat-id="r0">
            <tr ng-repeat="(si,stu) in students=(persons|orderBy:'sort') track by $index" on-repeat-finished-render>
              <td>{
       {si+1}}</td>
              <td>{
       {stu.id}}</td>
              <td>{
       {stu.name}}</td>
              <td>{
       {stu.gender}}</td>
              <td>{
       {stu.age}}</td>
              <td>
                <span class="button" ng-click="changeSort(students, si, -1, 'sort')" ng-if="!$first">上移</span>
                <span class="split" ng-if="!$first&&!$last"></span>
                <span class="button" ng-click="changeSort(students, si, 1, 'sort')" ng-if="!$last">下移</span>
              </td>
            </tr>
          </tbody>
        </table>
        <script> var myApp = angular.module('myApp', []); myApp.directive('onRepeatFinishedRender', function ($timeout) { return { restrict: 'A', link: function (scope, element, attr) { if (scope.$last === true) { $timeout(function () { scope.$emit('ngRepeatFinished', element); }); } } }; }); myApp.controller('userCtrl', function ($scope, $http) { $scope.persons = [{ id: "161112001", sort: 0, name: "赵子龙", gender: "男", age: "18" }, { id: "161112002", sort: 2, name: "吕布", gender: "男", age: "18" }, { id: "161112003", sort: 1, name: "貂蝉", gender: "女", age: "18" }, { id: "161112004", sort: 3, name: "孙尚香", gender: "女", age: "18" }]; $scope.changeSort = function (arr, index, up, attr) { var temp; temp = arr[index].sort; arr[index][attr] = arr[index + up][attr]; arr[index + up][attr] = temp; return false; }; $scope.$on("ngRepeatFinished", function (repeatFinishedEvent, element){ console.log(element.parent().attr("repeat-id")); }) }) </script>
      </body>
    </html>

文／jicemoon（简书作者）  
原文链接：http://www.jianshu.com/p/4ead962e9dac  
著作权归作者所有，转载请联系作者获得授权，并标注“简书作者”。

源引：http://www.jianshu.com/p/4ead962e9dac

[Link 1]: http://pan.baidu.com/s/1c2oaBcO