iamvishnusankar / typeorm-typedi-extensions

Dependency injection and service container integration with TypeORM using TypeDI library.

TypeDI Service container integration with TypeORM

This package provides decorators for TypeORM that can be used with TypeDI.

Installation

To start using TypeDI install the required packages via NPM:

npm install typeorm-typedi-extensions typedi reflect-metadata

Import the reflect-metadata package at the first line of your application:

import 'reflect-metadata';

// Your other imports and initialization code
// comes here after you imported the reflect-metadata package!

You need to enable emitting decorator metadata in your Typescript config. Add these two lines to your tsconfig.json file under the compilerOptions key:

"emitDecoratorMetadata": true,
"experimentalDecorators": true,

Configure TypeORM in your app to use the TypeDI container before you create a connection:

import { createConnection, useContainer } from 'typeorm';
import { Container } from 'typeorm-typedi-extensions';
//       ▲ Notice how we import container from this library, instead of TypeDI.

/** Tell TypeORM to use the container provided by this lib to resolve it's dependencies. */
useContainer(Container);

/** Create a connection and start using TypeORM. */
createConnection({
  /* <connection options> */
}).catch(error => {
  console.error(`Couldn't connect to the database!`);
  console.error(error);
});

Usage

This package exposes three decorators all three decorators can be used on properties or on constructor parameters.

IMPORTANT: To allow TypeDI to resolve the dependencies on your classes you must mark them with @Service decorator from the TypeDI package.

@InjectConnection decorator

Injects Connection from where you can access anything in your connection. Optionally, you can specify a connection to inject by name in the decorator parameter.

import { Service } from 'typedi';
import { Connection } from 'typeorm';
import { InjectConnection } from 'typeorm-typedi-extensions';

@Service()
export class MyCustomClass {
  @InjectConnection()
  private propertyInjectedConnection: Connection;

  constructor(@InjectConnection() private constructorInjectedConnection: Connection) {}
}

@InjectManager decorator

Injects EntityManager from where you can access any entity in your connection. Optionally, you can specify a connection to inject by name in the decorator parameter.

import { Service } from 'typedi';
import { EntityManager } from 'typeorm';
import { InjectManager } from 'typeorm-typedi-extensions';

@Service()
export class MyCustomClass {
  @InjectManager()
  private propertyInjectedEntityManager: EntityManager;

  constructor(@InjectManager() private constructorInjectedEntityManager: EntityManager) {}
}

@InjectRepository decorator

Injects Repository, MongoRepository, TreeRepository or custom repository of some Entity. Optionally, you can specify a connection to inject by name in the decorator parameter.

import { Service } from 'typedi';
import { Repository } from 'typeorm';
import { InjectRepository } from 'typeorm-typedi-extensions';
// MyDatabaseModel is a TypeORM entity (class marked with `@Entity()` decorator)
import { MyDatabaseModel } from './entities/post.entity.ts';

@Service()
export class MyCustomClass {
  @InjectRepository(MyDatabaseModel)
  private propertyInjectedRepository: Repository<MyDatabaseModel>;

  constructor(@InjectRepository(MyDatabaseModel) private constructorInjectedRepository: Repository<MyDatabaseModel>) {}
}

Example with custom connection name:

@Service()
export class PostRepository {
  @InjectRepository(Post, 'custom-con-name')
  private repository: Repository<Post>;
}

You can also inject custom Repository of some Entity. To make this work have to create the class which extends the generic Repository<T> class and decorate it with EntityRepository<T> decorator.

import { Service } from 'typedi';
import { Repository, EntityRepository } from 'typeorm';
import { InjectRepository } from 'typeorm-typedi-extensions';
// UserModel is a TypeORM entity (class marked with `@Entity()` decorator)
import { UserModel } from './entities/user.entity.ts';

@Service()
@EntityRepository(UserModel)
export class UserRepository extends Repository<UserModel> {
  public findByEmail(email: string) {
    return this.findOne({ email });
  }
}

@Service()
export class PostService {
  constructor(
    @InjectRepository()
    private readonly userRepository: UserRepository
  ) {}

  public async userExist(user: User): boolean {
    return (await this.userRepository.findByEmail(user.email)) ? true : false;
  }
}