javascript - 如何使用 AngularJS 过滤对象数组？

Question

背景

上周我一直在自学 AngularJS。我创建了一个基本应用程序，用于获取每个 Twitch channel 的 Twitch 数据，并创建一个包含以下属性的“ channel ”对象数组；名称、 Logo url、流媒体(是或否)和 channel url。到目前为止，我已经使用 Angular 通过 ng-repeat 指令将每个 channel 对象的属性打印到表中(喜欢这个功能)。

问题/疑问

每当用户单击在线和离线按钮时，我希望能够对表中的对象列表进行排序，从而通过其“流”属性过滤 channel 。不幸的是，我似乎无法弄清楚如何按其属性过滤 channel 。有人可以帮忙吗？

HTML

  <div ng-controller="MainController" >
  <div class="container" id="test">
    <div class="row">
        <header>
            <ul id="mainMenu">
                <li class="activeMenu" ng-click="filterGo('streaming')">All</li>
                <li ng-click="filterGo('streaming')">Online</li>
                <li ng-click="filterGo('streaming')">Offline</li>
            </ul>
        </header>
        <div class="center-block" >
        <table class="table table-hover" >
            <thead>
                <tr>
                    <th class="text-center">Logo</th>
                    <th class="text-center">Channel</th>
                    <th class="text-center">Online</th>
                </tr>
            </thead>
            <tbody>
                <tr ng-repeat="channel in twitchChannels | filter:filtered"   ng-click="setSelected();">
                    <td ><img id="size" ng-src="{{ channel.logo }}"></td>
                    <td >{{ channel.user }}</td>
                    <td >{{ channel.streaming }}</td>
                </tr>
             </tbody>
            </table>
        </div>
    </div>
  </div>

JS

var arr = ["ESL_SC2", "OgamingSC2", "cretetion", "freecodecamp", "habathcx", "RobotCaleb", "noobs2ninjas"];
var channels = [];
var count = 0;
var online = "";

// channel object 
function Channel(user, name, logo, streaming) {
    this.user = user;
    this.name = name;
    this.logo = logo;
    this.streaming = streaming;
    this.url = "https://www.twitch.tv/" + this.name;
}

var app = angular.module('myApp', []);


app.controller('MainController', function($scope, $http, $window) { 
    // loops through array of channels 
    for (var i = 0; i < arr.length; i++) {

        (function(i) { 

            $http.get("https://wind-bow.gomix.me/twitch-api/users/" + arr[i]).success(function(data) {

                var channel = data.display_name;
                var name = data.name;
                var logo = data.logo;

                $http.get("https://wind-bow.gomix.me/twitch-api/streams/" + arr[i]).success(function(json) {
                    var streaming = (json.stream === null) ? false : true;
                    if(streaming) {
                        online = "YES";
                        channels[count] = new Channel(channel, name, logo, online);
                    } else {
                        online = "NO";
                        channels[count] = new Channel(channel, name, logo, online);
                    }
                    count++;
                });
            });
         })(i);
    }

    $scope.twitchChannels = channels;

    // if channel row is clicked take user to url 
    $scope.setSelected = function() {
        $scope.selected = this.channel.url;
        $window.open($scope.selected);
    };

     // Need help here! 
     $scope.filterGo = function(x) {    
        $scope.filtered = x;
    }

});

这里有一个引用链接:http://codepen.io/bryanpleblanc/pen/jBBmgN

Answer 1

将您的 filterGo 函数更改为此

$scope.filterGo = function(x) {
        $scope.filtered = channels.filter(c => c.streaming === x);
}

和您的ng-click到

<li ng-click="filterGo('YES')">Online</li>
<li ng-click="filterGo('NO')">Offline</li>

注意

您最好使用 bool 值而不是 YES 和 NO。这会更容易。

像这样

$http.get("https://wind-bow.gomix.me/twitch-api/streams/" + arr[i]).success(function(json) {
    channels[count] = new Channel(channel, name, logo, json.stream !== null);
    count++;
});

你的按钮

<li ng-click="filterGo(true)">Online</li>
<li ng-click="filterGo(false)">Offline</li>

还有过滤器

$scope.filterGo = function(x) {
        $scope.filtered = channels.filter(c => c.streaming);
}