Cross-Platform UI in GitHub Desktop
Although the overall flow and architecture are shared, the implementations are often quite different. For example, although both platforms use WebKit, the bridging APIs are very different.
On OS X, the JavaScriptCore APIs allow us to pass arbitrary objects, functions, and arrays between Objective-C/Swift and JavaScript. Native code can call methods on JavaScript objects, and JavaScript code can call methods on native objects, without any special handling. We can also define protocols to specify which properties of our objects should be bridged.
CefSharp, on the other hand, does not bridge arrays or functions. JavaScript objects can call methods on native objects, but not on the properties of native objects. Native objects cannot call methods on JavaScript objects; you ask the ChromiumWebBrowser to evaluate a string of JavaScript source instead. Since the comparison graph is largely asynchronous, requiring both callbacks and arrays, this motivates a set of JavaScript shims baked into the comparison graph at build time.
