angularjs orderBy有多个函数,如何反转？

我有一个ng-repeat迭代一组对象,需要一些函数来提取我想要排序的值.

我的ng-repeat看起来像这样：

ng-repeat="row in rows | orderBy: [sortFnOne,sortFnTwo,...]"

我遇到麻烦的是,我希望sortFnOne被颠倒过来.这些是提取我无法使用简单属性访问的字符串,因为它正在对数据进行一些转换以生成我尝试排序的这些值.

如果它很简单,我知道我会这样做：

ng-repeat="row in rows | orderBy: ['-id','name','-status',...]"

如果这些功能只是返回布尔我可以！获取我想要的结果的返回值,但其中一些是返回字符串,有些是以YYYY-MM-DD格式返回日期.

我自己也遇到过这个限制……没有办法用orderBy过滤器来反转函数完成的排序.

据我所知,没有简单的方法可以在原生JavaScript API中重现这种带方向的复合排序(按’A’升序然后’B’降序排序).

Array.prototype.sort通过比较函数提供基本排序(有关详细信息,请参阅MDN docs),但无法在不编写其他比较函数的情况下轻松切换排序顺序(反向),并且它不提供复合排序的解决方案.我们需要的是一个紧凑的表示法来指定多个排序的方向和优先级.

前段时间我写了这个助手来帮助解决这个问题.

var orderByAgeThenName = new OrderByBuilder().asc(getAge).asc(getName).build();
  var friendsByAgeThenName = orderByAgeThenName(friends);

  var orderByNameThenAge = new OrderByBuilder().desc(getName).asc(getAge).build();
  var friendsByNameThenAge = orderByNameThenAge(friends);

这不是角度过滤器,因此只需将其包装在控制器方法中并从模板中调用它即可.或者,只需将顺序应用于控制器内的阵列即可.

我想这可以适应角度过滤器……

可运行样本：

angular.module('orderByExample',[])
.controller('ExampleController',['$scope',function($scope) {
  var friends =
    [{name:'Jon',phone:'555-1212',age:10},{name:'Zach',phone:'555-2276',age:7},phone:'555-9876',age:19},phone:'555-9276',age:13},{name:'Mike',phone:'555-4321',age:21},{name:'Adam',phone:'555-5678',age:35},{name:'Julie',phone:'555-8765',age:29}];

  function getName(f){
    return f.name;
  }

  function getAge(f){
    return f.age;
  }
  
  var orderByName       = new OrderByBuilder().desc(getName).build();
  var orderByNameAndAge = new OrderByBuilder().desc(getName).asc(getAge).build();

  $scope.friendLists = [
    {label:'Not Ordered',friends: friends},{label:'Name DESC',friends: orderByName(friends)},{label:'Name DESC,Age ASC',friends: orderByNameAndAge(friends)}
  ];
  
}]);




function OrderByBuilder(orderings){
  var _orderings = [];

  return {
    asc: function(fn){
      addOrdering(true,fn);
      return this;
    },desc: function(fn){
      addOrdering(false,build: build
  };

  function addOrdering(asc,fn){
    _orderings.push({
      getterFn: fn,asc: asc
    });
    return this;
  }

  function build(){
    var compare = _orderings.reverse().reduce(function(nextComparer,ordering){
      return getComparerFn(ordering,nextComparer);
    },null);

    return function(xs){
      return xs.slice().sort(compare);
    };
  }

  // a comparerFn has the following signature:
  //		function(a: obj,b: obj): int

  function getComparerFn(ordering,nextComparer){
    var next = nextComparer || function(a,b){ return 0; };
    var getVal = ordering.getterFn;

    return function(a,b){
      var aVal = getVal(a);
      var bVal = getVal(b);
      if(aVal < bVal){ return ordering.asc ? -1 :  1; }
      if(aVal > bVal){ return ordering.asc ?  1 : -1; }
      return next(a,b);
    };
  }
}

<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.4.0-beta.6/angular.min.js"></script>
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">

<div ng-app="orderByExample">
  <div ng-controller="ExampleController">
    <div class="row">
      <div ng-repeat="friendList in friendLists" class="col-sm-4">
        <h4>{{friendList.label}}</h4>
        
        <table class="table table-bordered table-condensed">
          <tr>
            <th>Name</th>
            <th>Phone Number</th>
            <th>Age</th>
          </tr>
          <tr ng-repeat="friend in friendList.friends">
            <td>{{friend.name}}</td>
            <td>{{friend.phone}}</td>
            <td>{{friend.age}}</td>
          </tr>
        </table>
      </div>
    </div>
  </div>
</div>

原文地址：https://www.jb51.cc/angularjs/141140.html