Service

Create Service

For example, we create a Service student in the module demo-student

1. Cli command

$ vona :create:bean service student --module=demo-student

2. Menu command

TIP

Context Menu - [Module Path]: Vona Create/Service

Service Definition

@Service()
export class ServiceStudent extends BeanBase {}

• Inherited from the BeanBase class
• Use Serivce decorator

Use Service

The use of Service can be explained from different dimensions

• Dependency Injection, Dependency Lookup

• Module Scope: Service

1. Dependency injection

Inject ServiceStudent into ControllerStudent of module demo-student, the code is as follows:

• Based on Class type

import { ServiceStudent } from '../service/student.ts';

class ControllerStudent {
  @Use()
  serviceStudent: ServiceStudent;
}

• Based on Bean identifier

import type { ServiceStudent } from '../service/student.ts';

export class ControllerStudent {
  @Use('demo-student.service.student')
  serviceStudent: ServiceStudent;
}

• Since the imported ServiceStudent is a type, the Bean identifier of Service needs to be specified

2. Dependency lookup

• Lookup in this module

class ControllerStudent {
  findOne() {
    return this.scope.service.student.findOne();
  }
}

• Lookup cross-module

class ControllerStudent {
  findOne() {
    return this.$scope.demoStudent.service.student.findOne();
  }
}

3. Dependency lookup (API)

_getBean

1. Lookup based on Bean class

class ControllerStudent {
  findOne() {
    const serviceStudent = this.bean._getBean(ServiceStudent);
  }
}

• this.bean === this.app.bean, which is the global ioc container

2. Lookup based on Bean identifier

class ControllerStudent {
  findOne() {
    const serviceStudent = this.bean._getBean('demo-student.service.student');
  }
}

Request scope

If we want to create a request-scope Bean instance, then we only need to invoke the _getBean method of the ctx container

class ControllerStudent {
  findOne() {
    const serviceStudent1 = this.ctx.bean._getBean(ServiceStudent);
    const serviceStudent2 = this.ctx.bean._getBean('demo-student.service.student');
    // serviceStudent1 === serviceStudent2
}
}

_newBean

1. Create a new instance based on the Bean class

import { ServiceMenu } from 'vona-module-home-base';

class ControllerStudent {
  findOne() {
    const serviceMenu = this.bean._newBean(ServiceMenu);
  }
}

2. Create a new instance based on the Bean identifier

class ControllerStudent {
  findOne() {
    const serviceMenu = this.bean._newBean('home-base.service.menu');
  }
}