Using-Plug-ins

Using Plug-ins

Angel is designed to be extensible. As such, it exposes a typedef, AngelConfigurer, that has special privileges within the framework - they act as plug-ins and can be called via app.configure().

Plug-ins simply need to accept an Angel instance as a parameter, and return a Future (the result of which will be ignored, unless it throws an error). Angel instances have several facilities available to be customized, and thus it is easy to use a custom plug-in to bring about desired functionality within your application.

  1. typedef Future AngelConfigurer(Angel app);

As a convention, Angel plug-ins should be hooked up before the call to startServer.

  1. import 'dart:io';
  2. import 'package:angel_framework/angel_framework';
  4. plugin(Angel app) async {
  5.   print("Do stuff here");
  6. }
  8. main() async {
  9.   Angel app = new Angel();
  10.   await app.configure(plugin);
  11.   await app.startServer();
  12. }

Execution Order

Plugins are usually immediately invoked by app.configure(). However, you may run into certain plug-insthat depend on other facilities already being available, or all of your services already being mounted. You can set aside a plug-in to be run just before server startupby adding it to app.startupHooks, instead of directly calling app.configure().

  1. app.startupHooks.addAll([
  2.   myPlugin(),
  3.   AngelWebSocket().configureServer,
  4.   fooBarBazQuux()
  5. ]);

Likewise, you can add hooks that run just before the app is shutdown, via Angel.shutdownHooks.

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