title: File upload in extjs 4.2 without form.submit()
body: <p>I'm trying to upload a file (as of now of any extension) in extjs. I have a model and store. the file upload happens from a window and I dont have a form in the window. All example I tried in the net are with form.submit(). I instead use and Ajax call as below to send the data to the server. </p>
  
  <pre><code>Ext.Ajax.request({
  
              url : 'qaf/saveSetupDetails.action',
  
              params : {
                  'data' : recordsToSend
              },
              failure : function(response){
                  //console.log('error connecting controller');
              },
              success : function(response){
                  //console.log('successfully submitted');
              }
          });
  </code></pre>
  
  <p>The records to send in the data is got as below.</p>
  
  <pre><code>var store = Ext.getStore('SomeStore');
          var modifiedRecords = store.getModifiedRecords();
          var recordsToSend = [];
          if(modifiedRecords.length &gt; 0){
              Ext.each(modifiedRecords, function(record){
                  recordsToSend.push(record.data);//I'm sure that this is so dump but this is how I do it for other records which are string and not sure how to do it for a file...
              });
          }
          Ext.USE_NATIVE_JSON = true;
          recordsToSend = Ext.encode(recordsToSend);
  </code></pre>
  
  <p>While setting the record in the model, I use the below code..</p>
  
  <pre><code>var rec = Ext.create('QAF.model.MyModel');
  rec.set('modelField',Ext.getCmp('fileUploadCompID').value);
  </code></pre>
  
  <p>I received a 500 status error with the response <code>"Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.commons.CommonsMultipartFile]"</code></p>
  
  <p>I'm sure that this is because of the way I set the value to the model as <code>Ext.getCmp('fileUploadCompID').value</code> gives the file name. Please let me know how to set the file to the model and what data type I have to specify for the field in the model.</p>
  
  <p>Below is how I try to retrieve the file in the spring controller.</p>
  
  <pre><code>@RequestMapping (value = "/qaf/saveSetupDetails.action")
      public @ResponseBody
      void saveSetupDetails(@RequestParam CommonsMultipartFile data)throws Exception{
          log.info("Enter into saveSetupDetails method..." + data.getOriginalFilename());
      }
  </code></pre>
  
  <p>Please let me know what I'm doing wrong and what has to be done to fix this...</p>