documentcloud/backbone — pull request #835 by jayred (2011-12-31 20:54:41+00:00)
Title: Add support for sending only updated attributes on Backbone.sync

For large models that are being updated with only a few attributes, it can be useful to send only the changed data to the server for persistence. This reduces data traffic and request time and can simplify server-side code.

To enable this partial update, users can pass ```{partialUpdate: true}``` in options hash of Model.save:

```javascript
var book = new Backbone.Model({
title: "The Rough Riders",
author: "Theodore Roosevelt"
});

book.save(); // request.data => {"title": "The Rough Riders", "author": "Theodore Roosevelt"}

book.save({author: "Teddy"}); // request.data => {"title": "The Rough Riders", "author": "Teddy"}

book.save({author: "Mr. Roosevelt"}, {partialUpdate: true}); // request.data => {"author": "Mr. Roosevelt"}
```