When the text editor's contents are changed, the model is updated. However, if the model is updated from another input source, the content in the text editor window does not change.
For example, visit this link: http://plnkr.co/edit/BSkm3u8XuKEFMOXmlS6K?p=preview
I believe I need to define a watcher for this model and manually update the content in the editor, but I am unsure how to implement this behavior.