BackboneJS - Collezione findWhere

Descrizione

È come il where metodo, ma restituisce direttamente solo il primo modello nella raccolta che corrisponde agli attributi passati.

Sintassi

collection.findWhere(attributes)

Parametri

attributes - Rappresentano la proprietà di un modello definito.

Esempio

<!DOCTYPE html>
<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">
      
         //'Players' is a model name and containa default values
         var Players = Backbone.Model.extend ({
            defaults: {
               id:"",
               name: "",
               country:""
            }
         });

         //The 'PlayersCollection' is an instance of the collection
         var PlayersCollection = Backbone.Collection.extend ({
         
            //The model 'Players' is specified by overriding the "model" property of the collection
            model: Players
         });
         $(function() {
            var mycollection = new PlayersCollection();

            // The set() method to sets the values for 'id', 'name' and 'country' attributes, specified 
            //in the model "Players"
            mycollection.set ([
               {id:1, name: 'dhoni', country:'india'},
               {id:2, name:'gayle', country:'west indies'},
               {id:3, name: 'maxwell', country:'australia'},
               {id:4, name: 'duminy', country:'south africa'}
            ]);

            // The findWhere() method finds the model containing with the id '1'
            var res = mycollection.findWhere({id:1});

            //Display the result in  the JSON format
            document.write("The values of matched attribute are: ",JSON.stringify(res));
         });
      </script>
      
   </body>
</html>

Produzione

Eseguiamo i seguenti passaggi per vedere come funziona il codice sopra:

Salva il codice sopra nel file findwhere.htm file.
Apri questo file HTML in un browser.

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