AleksanderBodurri / hook-decorator

Class decorator to hook before/after functions into method calls.

hook-decorator

Inspired by rails action controller filters.

This decorator patches before/after hooks into every method (referred to in API as actions) defined by a class.

Installation

npm i hook-decorator --save

Usage

Example

import { Hook } from 'hook-decorator';

@Hook({
  beforeAction: {
    callback: (classInstance: Logger) => console.log(classInstance.pre),
  },
  afterAction: {
    callback: (classInstance: Logger) => console.log(classInstance.post),
  },
})
class Logger {
  pre = 'hello';
  post = '!';

  log(): void {
    console.log('world');
  }
}

const logger = new Logger();
logger.log();
// hello
// world
// !

Configuration

export interface HookConfig {
  beforeAction?: Hook;
  afterAction?: Hook;
  options?: HookConfigOptions;
}

interface Hook {
  callback: Callback;
  only?: string[];
  except?: string[];
}

type Callback = (classInstance?: any) => any;

interface HookConfigOptions {
  patchAngular: boolean;
}

Angular lifecycles

Angular lifecycle methods are called differently from other methods. Hook decorator offers experimental support for these methods via the patchAngular option in HookConfigOptions.

License

MIT