Even these Delphi developers who have only set the very first steps into web client development will realize that quite a few important functionalities in web clients are executed only asynchronously by the browser.
For the developers behind the browser, the user experience comes first and a UI that freezes is a big no-go. At all times, the user interface should remain response. The user should never get the impression that the browser or the machine hangs while navigating on the internet.
Traditionally, the browser developers solved this "issue" by JavaScript event handlers that are called asynchronously when the result of a certain operation is ready and meanwhile, any other code can continue to execute. This is no different in TMS WEB Core web client applications written in Object Pascal (but of course compiled to JavaScript by the pas2js compiler). Here, we typically solved this with the Object Pascal event paradigm. When a class instance method is invoked that can only have its result asynchronously, this class instance triggers an event handler when the underlying function completed. When the pas2js compiler also introduced support for anonymous methods, we offered for various such asynchronous operations, anonymous result handlers.
With the new upcoming v1.7 release, we overhauled the code already significantly, offering equivalent TJSPromise returning functions in many components and classes that were before based on class event handlers or anonymous methods for handling asynchronous behavior.
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