title: Backbone model save state
body: <p>I use backbone model to save the data to the server. then I handle the success or error callback after save(post) and set wait:true. my question is why backbone model only trigger the error callback when server returns a string? when server returns a json or any number, it will go to the success. the problem is if I want to return a multiple error message and I want to put all error message into a collection(json), it will never go to error callback. sample code like</p>
  
  <pre><code>echo 'success'; //actually it will go to error callback cuz it return a string(any string)
  echo json_encode($some_array); // it will go to success
  echo 200/anynumber; // it will go to sucess
  </code></pre>
  
  <p>My solution is if I wanna return a multiple message, I can separate those message by a delimiter, and use javascript native function split to separate them. is there any better solution like maybe I can return a state(indicate either success or error) and a collection from server?</p>
  
  <pre><code>model code looks like:
  somemodel.save({somedata},
      {
          success:function(a,b,c){}, 
          error:function(b,c,d){},
          wait: true
      });
  </code></pre>