For some project you may want to use your own Application type because any of the existing in YABF match your requirements. However if you want to use some generic tools provided by YABF you can inherit from AbstractApplication.

Here is a recipe about "How to create a new Application type".

Create a new file on which you'll create your application class.

import { AbstractApplication } from 'yabf'

export class CLIApplication extends AbstractApplication {}

This method will describe to the generic createInstance() method how to create the new application (CLIApplication in our case).

buildInstructions() returns an array of IBuildInstruction ({ provide: InjectionClass<any>, dependencies: InjectionSelector<any>[] }). The first element of this array have to be the instruction for your class itself.

import { AbstractApplication } from 'yabf'

export class CLIApplication extends AbstractApplication {
  protected buildInstructions() {
    return [
      { provide: CLIApplication, dependencies: [] }
    ]
  }
}

If you don't provide instruction to build your app, it will throw a MissingBuildInstruction error.

The start() method acts like an entrypoint for your application. It is used to "start" the application.

import { AbstractApplication } from 'yabf'

export class CLIApplication extends AbstractApplication {
  // ...

  start(): void {
    while (true) {
      // ...
    }
  }
}

To inject new dependencies, you have to owerwrite the constructor and add the instructions in buildInstructions() method.

export class CLIApplication extends AbstractApplication {
  constructor(injector: IDependencyInjectionProvider, private parser: CLIParser) {
    super(injector)
  }

  // ...

  private buildInstructions() {
    return [
      { provide: CLIApplication, dependencies: [CLIParser] },
      { provide: CLIParser, dependency: []}
    ]
  }
}

We don't specify injector in buildInstructions because YABF will automatically inject it. You shoud use buildInstructions() only for custom dependencies.

To avoid this behavior, you should overwrite createInstance() static method.