We now have an API to target; it's time to start building the user interface for our chat. We'll start by thinking about talking to the API that we've just built, then implementing that piece. Next, we'll build the actual HTML we need to render the three pages used by this application. From here, we'll move onto perhaps the most challenging part of the front end—building the DOM event handlers and manipulators. Finally, we'll see if we can enhance the responsiveness of the application by throwing a web worker into the mix.
The API communication paths in our UI are inherently concurrent—they send and receive data over a network connection. Therefore, it's in the best interest of our application architecture that we take time to hide the synchronization mechanisms from the rest of the system as best as we can. To communicate with our API, we'll use instances of the XMLHttpRequest class. However, as we've seen in earlier chapters of this book, this class can...