title: ExtJS creating record from existing store
body: <p>I have created an ext store like so:</p>
  
  <pre><code>var store = new Ext.data.JsonStore({
         root: 'vars',
         fields: [{ name: 'rec_id', mapping: 'rec' }, { name: 'identity', mapping: 'id'}]
  });
  </code></pre>
  
  <p>This works alright when I add data to the store via <code>loadData();</code> and some json which looks like:</p>
  
  <pre><code>{ vars : {rec: '1', id:'John'} }
  </code></pre>
  
  <p>My problem is that if I use <code>add();</code> to get this record into the store I have to first create it as an <code>Ext.data.Record</code> object. </p>
  
  <p>I do this as pointed out here: <a href="https://stackoverflow.com/a/7828701/1749630">https://stackoverflow.com/a/7828701/1749630</a> and it works ok. </p>
  
  <p>The issue I have is that the records are entered with their mapped parameters rather than the ones I set. I.e, 'rec_id' becomes 'rec' and 'identity' becomes 'id'.</p>
  
  <p>What am I doing wrong here?</p>