Magic Method

You can access dynamic properties or methods within a class using __get__ and __set__

Example: Module Scope

To make using the IOC container more concise and intuitive, VonaJS recommends prioritizing the dependency lookup strategy, which reduces the use of decorator functions and type annotations. Accessing module resources through the Module Scope object is one mechanism for implementing the dependency lookup strategy

• See: Module Scope

For example, the demo-student module contains a student model for crud operations. You can use the model like this:

import { ModelStudent } from '../model/student.ts';

async findMany(params) {
  const model = this.bean._getBean(ModelStudent);
  return await model.selectAndCount(params);
}

Using magic method:

async findMany(params) {
  return await this.scope.model.student.selectAndCount(params);
}

• this.scope.model.xxx: Dynamically retrieve the model instance in the current module using magic method

Example: CRUD (Magic Method)

Vona ORM uses magic method to further simplify data manipulation code

• See: CRUD (Magic Methods)

For example, to query student information by the id field, the code is as follows:

async findOne(id) {
  return await this.scope.model.student.get({ id });
}

Using magic method:

async findOne(id) {
  return await this.scope.model.student.getById(id);
}

• The system automatically parses the id parameter from the getById method name and then calls the actual CRUD method, which is: get({ id })

Creating a Class

Magic method can be implemented in any class. Taking Service as an example, create a Service color in the module demo-student with the following code:

• For information on creating a Service, see: Service

import { BeanBase } from 'vona';
import { Service } from 'vona-module-a-bean';

@Service()
export class ServiceColor extends BeanBase {}

__get__

Then, use __get__ to retrieve the color values

1. Add a code skeleton

In the VSCode editor, enter the code snippet aopmagicget to automatically generate a code skeleton:

@Service()
export class ServiceColor extends BeanBase {
+ protected __get__(prop: string) {}
}

2. Implement custom logic

@Service()
export class ServiceColor extends BeanBase {
+ private _colors = {
+   red: '#FF0000',
+   green: '#00FF00',
+   blue: '#0000FF',
+ };

  protected __get__(prop: string) {
+   return this._colors[prop];
  }
}

3. Adding Type Merging

Providing type definitions for colors using interface type merging

declare module 'vona-module-demo-student' {
  export interface ServiceColor {
    red: string;
    green: string;
    blue: string;
  }
}

4. Using Magic Method

async test() {
  console.log(this.scope.service.color.red);
  console.log(this.scope.service.color.green);
  console.log(this.scope.service.color.blue);
}

__set__

Then, use __set__ to set the color values

1. Add a code skeleton

In the VSCode editor, enter the code snippet aopmagicset to automatically generate a code skeleton:

@Service()
export class ServiceColor extends BeanBase {
+ protected __set__(prop: string, value: any): boolean {
+   return false;
+ }
}

2. Implement custom logic

@Service()
export class ServiceColor extends BeanBase {
  private _colors = {
    red: '#FF0000',
    green: '#00FF00',
    blue: '#0000FF',
+   black: '',
  };

  protected __set__(prop: string, value: any): boolean {
+   if (this._colors[prop] === undefined) return false;
+   this._colors[prop] = value;
+   return true;
  }
}

• If a value is set for prop, return true; otherwise, return false

3. Add type merging

Provide type definitions for colors using the interface type merging mechanism

declare module 'vona-module-demo-student' {
  export interface ServiceColor {
    red: string;
    green: string;
    blue: string;
+   black: string;
  }
}

4. Using magic method

async test() {
  this.scope.service.color.black = '#000000';
  console.log(this.scope.service.color.black);
}