title: Passing an array via extraParams to a store only gives the last value in ExtJS
body: <p>I am building a web application and there is a part there where I need to load records from a store given a set of ids. The way I went about this was to get all the ids, store them in an array, and then load the store with that array as an extra param.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>for(var i = 0 ; i &lt; store.count() ; i++){
      console.log("id person = " + store.getAt(i).get("ID_PERSON"));
      idArray.push(store.getAt(i).get("ID_PERSON"));
  }
  
  console.log("id array = " + idArray);
  
  store = Ext.getStore('borrowerListStore');
  
  store.getProxy().extraParams={
      idArray: idArray
  };
  
  store.load({
      callback: function(records, operation, success) {
  
          var total = operation.request.scope.reader.jsonData['total'];
          var message = operation.request.scope.reader.jsonData['message'];
  
          console.log("message  = " + message);
      }
  
  });
  </code></pre>
  
  <p>First, I go though my initial store then get all the ids and store them in an Array. After that, I declare my store, I get the proxy, I set the params, and then I use the idArray I assembled as the array. </p>
  
  <p>The console line shows me proper values for example <code>77, 24, 80</code> so I know that I passed 3 values. </p>
  
  <p>Then in my PHP code linked in the <code>read</code> method of my store, I do this:</p>
  
  <pre><code>else if(isset($_GET['idArray'])){
  
      $idArray = $_GET['idArray'];
  
      $array = $idArray;
  
      for($i = 0 ; $i &lt; count($idArray) ; $i++){
          array_push($array, $idArray[$i]);
      }
  
      $sql = "SELECT * FROM TABLE WHERE ID IN(".implode(',',$array).")";
  
  $result = mysql_query($sql);    
  
      $res-&gt;message .= " Loaded data ";
      $res-&gt;message .= " sql = " . $sql;
      $res-&gt;message .= " idArray = " . $idArray;
      $res-&gt;message .= " array = " . $array;
  
      $total = mysql_fetch_array($totalquery);
  }
  </code></pre>
  
  <p>So that when the store loads and I enter the callback function, I can see the messages that got returned.</p>
  
  <p>However, when I console out the messages, it seems to me that only the last array element is the only thing that my PHP received because the log would look like:</p>
  
  <pre><code>message  =  Message start  Loaded data  sql = SELECT * FROM TABLE WHERE ID IN() idArray = 80 array = 80
  </code></pre>
  
  <p>What's happening here? Why can't I seem to pass an array as extra param?</p>