Schedule decorators for TypeScript

The schedule decorators library provides a simple, ES5+ compatible, lightweight and universal decorator to easily make recurrent function calls. The decorator uses the standard window.setInterval() function internally, makes the code clearer and avoid code duplication.

Install

The easiest way is to install ts-schedule-decorators as dependency:

npm install ts-schedule-decorators --save

Usage

Schedule an instance method

Instance methods will be executed after instantiation.

@Schedulable()
class Cat {

  @Interval(1000)
  public meow() {
    console.log('Meeeooow')
  }
}

const garfield = new Cat()
// Displays:
// 2017-01-09 12:12:35 Meeeooow
// 2017-01-09 12:12:36 Meeeooow
// 2017-01-09 12:12:37 Meeeooow
...

Schedule a static method

Static methods will be executed on declaration.

@Schedulable()
class Cat {

  @Interval(1000)
  public static miaow() {
    console.log('Miaaooow')
  }
}

// Displays:
// 2017-01-09 12:16:41 Miaaooow
// 2017-01-09 12:16:42 Miaaooow
// 2017-01-09 12:16:43 Miaaooow
...

Allow manual invocation

By default and to be safe, an interval method cannot be invoked manually. However, you can avoid this behavior by setting the protectOriginal option to false.

@Schedulable()
class Cat {

  @Interval(1000)
  public static miaow() {
    console.log('Miaaooow')
  }
}

Cat.miaow()
// Displays:
// Uncaught Error: interval method cannot be invoked

@Schedulable()
class Cat {

  @Interval(1000, { protectOriginal: false })
  public static miaow() {
    console.log('Miaaooow')
  }
}

Cat.miaow()
// Displays:
// 2017-01-09 12:55:33 Miaaooow
// 2017-01-09 12:55:34 Miaaooow
// 2017-01-09 12:55:35 Miaaooow
// 2017-01-09 12:55:36 Miaaooow

Execute the method on the leading edge

If the option leading is set to true, then the method will be invoked on the leading edge as well.

@Schedulable()
class Cat {

  @Interval(1000, { leading: true })
  public static miaow() {
    console.log('Miaaooow')
  }
}

// Displays:
// 2017-01-09 12:18:18 Miaaooow
// 2017-01-09 12:18:19 Miaaooow
// 2017-01-09 12:18:20 Miaaooow
// 2017-01-09 12:18:21 Miaaooow
...

Stopping condition

The execution of the method can be stopped providing a function to the stop option. If the invokation of this function returns true, then the interval is cleared.

@Schedulable()
class Cat {

  public static stopIt: boolean = false
  
  @Interval(1000, { stop: self => return self.stopIt })
  public static miaow() {
    console.log('Miaaooow')
    Cat.stopIt = true
  }
}

// Displays:
// 2017-01-09 12:18:18 Miaaooow
// 2017-01-09 12:18:19 Miaaooow
// 2017-01-09 12:18:20 Miaaooow
// 2017-01-09 12:18:21 Miaaooow
...

License

Code licensed under MIT License.