Service

⚠️ Translation in Progress: This page is being translated. For now, please refer to the Chinese version.

Service is an abstraction layer for encapsulating business logic in complex business scenarios. It provides the following advantages:

Keeps Controller logic simpler
Maintains business logic independence - Services can be reused by multiple Controllers
Separates logic from presentation, making it easier to write test cases

Usage Scenarios

Data processing: When information needs to be retrieved from a database and calculated before displaying to users
Third-party service calls: Such as fetching GitHub information

Defining a Service

js

// app/service/user.js
const Service = require('egg').Service;

class UserService extends Service {
  async find(uid) {
    const user = await this.ctx.db.query(
      'select * from user where uid = ?',
      uid,
    );
    return user;
  }
}

module.exports = UserService;

Properties

Each Service instance has access to:

this.ctx: Current request Context object
this.app: Current Application object
this.service: Access to other Services
this.config: Application configuration
this.logger: Logger object for debugging

For more details, please refer to the Chinese documentation.