The Websocket protocol provides full-duplex communication channels over a single TCP connection. In the past, web clients had to employ long-polling or the repeated pinging of a server in order to achieve this kind of “push” functionality. Now, Websocket technology eliminates the need for such outdated techniques.
Set the disabled attribute to the result of an expression and Angular will disable / enable the element for you as needed.
If you want to act upon the change event of a text input or text area, assign a method to the change attribute.