BackboneJS collection.where()方法

用於通過使用集合中的匹配屬性來顯示模型。

語法

collection.where(attribute)

參數:

attribute: 它代表定義模型的屬性。

示例

<!DOCTYPE html>
   <head>
      <title>Collection Example</title>
         <script src="https://code.jquery.com/jquery-2.1.3.min.js" type="text/javascript"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.2/underscore-min.js" type="text/javascript"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.1.2/backbone-min.js" type="text/javascript"></script>
   </head>
   <body>
      <script type="text/javascript">
         //'Player' is a model name
         Player = Backbone.Model.extend({
            name: ""
         });

         //The 'PlayersCollection' is an instance of the collection
         PlayersCollection = Backbone.Collection.extend({
            model: Player  //The model 'Player' is specified by overriding the "model" property of the collection
         });
         var player1 = new Player({ name: "Dravid" });
         var player2 = new Player({ name: "Raina"});
         var player3 = new Player({ name: "Jadeja"});
         var mycollection = new PlayersCollection();

         //The 'player1','player2' and 'player3' are 3 instances added to the collection by using 'mycollection' instance
         mycollection.add(player1);
         mycollection.add(player2);
         mycollection.add(player3);

         //The where() method returns the model, which contains the name with "Raina" in the collection
         var myteam = mycollection.where({ name: 'Raina' });
         document.write("Total numbers of items that matches given attribute are:", +myteam.length);
      </script>
   </body>
</html>

輸出

讓我們進行以下步驟來看看上麵的代碼工作：

保存上述代碼到文件where.html
在瀏覽器打開這個HTML文件。