json-api-nestjs

This plugin works upon TypeOrm library, which is used as the main database abstraction layer tool. The module automatically generates an API according to JSON API specification from the database structure (TypeORM entities). It supports features such as requests validation based on database fields types, request filtering, endpoints extending, data relations control and much more. Our module significantly reduces the development time of REST services by removing the need to negotiate the mechanism of client-server interaction and implementing automatic API generation without the need to write any code.

Installation

$ npm install json-api-nestjs

Example

Once the installation process is complete, we can import the JsonApiModule into the root AppModule.

import {Module} from '@nestjs/common';
import {JsonApiModule} from 'json-api-nestjs';
import {Users} from 'database';

@Module({
  imports: [
    JsonApiModule.forRoot({
      entities: [Users]
    }),
  ],
})
export class AppModule {
}

After this, you have to prepare CRUDs with ready-to-use endpoints:

• GET /users
• POST /users
• GET /users/:id
• PATCH /users/:id
• DELETE /users/:id
• GET /users/{id}/relationships/{relName}
• POST /users/{id}/relationships/{relName}
• PATCH /users/{id}/relationships/{relName}
• DELETE /users/{id}/relationships/{relName}

Configuration params

The following interface is using for the configuration:

export interface ModuleOptions {
  entities: Entity[]; // List of typeOrm Entity
  controllers?: NestController[];  // List of controller, if you need extend default present
  connectionName?: string; // Type orm connection name: "default" is default name  
  providers?: NestProvider[]; // List of addition provider for useing in custom controller
  imports?: NestImport[]; // List of addition module for useing in custom controller
  options?: {
    requiredSelectField?: boolean; // Need list of select field in get endpoint, try is default
    debug?: boolean; // Debug info in result object, like error message
    pipeForId?: Type<PipeTransform> // Nestjs pipe for validate id params, by default ParseIntPipe
    operationUrl?: string // Url for atomic operation https://jsonapi.org/ext/atomic/
  };
}

You can extend the default controller:

import {Get, Param, Inject, BadRequestException} from '@nestjs/common';

import {Users} from 'database';
import {
  JsonApi,
  excludeMethod,
  JsonBaseController,
  InjectService,
  JsonApiService,
  ResourceObjectRelationships,
  Query,
} from 'json-api-nestjs';
import {ExampleService} from '../../service/example/example.service';

@JsonApi(Users, {
  allowMethod: excludeMethod(['deleteRelationship']),
  requiredSelectField: true,
  overrideRoute: 'user',
})
export class ExtendUserController extends JsonBaseController<Users> {
  @InjectService() public service: JsonApiService<Users>;
  @Inject(ExampleService) protected exampleService: ExampleService;

  public override getAll(query: Query<Users>): Promise<ResourceObject<Users, 'array'>> {
    if (!this.exampleService.someCheck(query)) {
      throw new BadRequestException({});
    }
    return this.service.getAll(query);// OR call parent method: super.getAll(query);
  }

  public override patchRelationship<Rel extends EntityRelation<Users>>(
    id: string | number,
    relName: Rel,
    input: PatchRelationshipData
  ): Promise<ResourceObjectRelationships<Users, Rel>> {
    return super.patchRelationship(id, relName, input);
  }

  @Get(':id/example')
  testOne(@Param('id') id: string): string {
    return this.exampleService.testMethode(id);
  }
}

You can overwrite the default config for the current controller using options in the decorator JsonAPi. Also you can specify an API method necessary for you, using allowMethod Defulat validation check only simple type and database structure. If you need custom pipe validation you can your owner pipe like this:

import { Query } from '@nestjs/common';
import {
  JsonApi,
  excludeMethod,
  JsonBaseController,
  InjectService,
  JsonApiService,
  Query as QueryType,
} from 'json-api-nestjs';

@JsonApi(Users, {
  allowMethod: excludeMethod(['deleteRelationship']),
  requiredSelectField: true,
  overrideRoute: 'user',
})
export class ExtendUserController extends JsonBaseController<Users> {
  @InjectService() public service: JsonApiService<Users>;
  @Inject(ExampleService) protected exampleService: ExampleService;

  public override getAll(
    @Query(ExamplePipe) query: QueryType<Users>
  ): Promise<ResourceObject<Users, 'array'>> {
    return super.getAll(query);
  }
}

import { ArgumentMetadata, PipeTransform } from '@nestjs/common';

import { Query } from 'json-api-nestjs';
import { Users } from 'database';

export class ExamplePipe implements PipeTransform<Query<Users>, Query<Users>> {
  transform(value: Query<Users>, metadata: ArgumentMetadata): Query<Users> {
    return value;
  }
}

Swagger UI

For using swagger, you should only add @nestjs/swagger and configure it

const app = await NestFactory.create(AppModule);

const config = new DocumentBuilder()
  .setTitle('JSON API swagger example')
  .setDescription('The JSON API list example')
  .setVersion('1.0')
  .build();

SwaggerModule.setup(
  'swagger',
  app,
  () => SwaggerModule.createDocument(app, config), // !!!Important: document as factory
  {}
);

Available endpoint method

Using Users entity and relation Roles entity as example

List item of Users

GET /users

Available query params:

• include - you can extend result with relations (aka join)

  GET /users?include=roles
  

  result of request will have role relation for each Users item

• fields - you can specify required fields of result query

   GET /users?fields[target]=login,lastName&fileds[roles]=name,key
  

  The "target" is Users entity The "roles" is Roles entity So, result of request will be have only fields login and lastName for Users entity and fields name and * key* for Roles entity

• sort - you can sort result of the request

   GET /users?sort=target.name,-roles.key
  

  The "target" is Users entity The "roles" is Roles entity So, result of the request will be sorted by field name of Users by ASC and field key of Roles entity by DESC.

• page - pagination for you request

  GET /users?page[number]=1page[size]=20
  

• filter - filter for query

  GET /users?filter[name][eq]=1&filter[roles.name][ne]=test&filter[roles.status][eq]=true
  

  The "name" is a field of Users entity The "roles.name" is name field of Roles entity The "eq", "ne" is Filter operand

  So, this query will be transformed like sql:

   WHERE users.name = 1 AND roles.name <> 'test' AND roles.status = true

Filter operand

type FilterOperand
{
in:string[] // is equal to the conditional of query "WHERE 'attribute_name' IN ('value1', 'value2')"
  nin: string[] // is equal to the conditional of query "WHERE 'attribute_name' NOT IN ('value1', 'value1')"
  eq: string // is equal to the conditional of query "WHERE 'attribute_name' = 'value1'
  ne: string // is equal to the conditional of query "WHERE 'attribute_name' <> 'value1'
  gte: string // is equal to the conditional of query "WHERE 'attribute_name' >= 'value1'
  gt: string // is equal to the conditional of query "WHERE 'attribute_name' > 'value1'
  lt: string // is equal to the conditional of query "WHERE 'attribute_name' < 'value1'
  lte:string // is equal to the conditional of query "WHERE 'attribute_name' <= 'value1'
  regexp: string // is equal to the conditional of query "WHERE 'attribute_name' ~* value1
  some: string // is equal to the conditional of query "WHERE 'attribute_name' && [value1]
}

Get item of Users

GET /users/:id

• include - you can extend result with relations (aka join)

  GET /users?include=roles
  

  result of request will have role relation for each Users item

• fields - you can specify required fields of result query

   GET /users?fields[target]=login,lastName&fileds[roles]=name,key
  

  The "target" is Users entity The "roles" is Roles entity So, result of request will be have only fields login and lastName for Users entity and fields name and * key* for Roles entity

Create item of Users

POST /users

• body - Create new User and add link to address

{
  "data": {
    "type": "users",
    "attributes": {
      "id": 0,
      "login": "string",
      "firstName": "string",
      "lastName": "string",
      "isActive": true,
      "createdAt": "2023-12-08T10:32:27.352Z",
      "updatedAt": "2023-12-08T10:32:27.352Z"
    },
    "relationships": {
      "addresses": {
        "id": "1",
        "type": "addresses"
      }
    }
  }
}

Update item of Users

PATCH /users/:id

• body - Update User with id 1 and update link to address and manager

{
  "data": {
    "id": "1",
    "type": "users",
    "attributes": {
      "id": 0,
      "login": "string",
      "firstName": "string",
      "lastName": "string",
      "isActive": true,
      "createdAt": "2023-12-08T10:34:57.752Z",
      "updatedAt": "2023-12-08T10:34:57.752Z"
    },
    "relationships": {
      "addresses": {
        "id": "2",
        "type": "addresses"
      },
      "manager": {
        "id": "2",
        "type": "users"
      }
    }
  }
}

Atomic operation

You can more information find here But you have additinal feature. For example: you will need create new Roles, then - create new Users and assign new Roles to new Users. If use native json api you need send 3 http request:

• POST /roles
• POST /users

but Atomic operation allow for one request.

{
   "atomic:operations":[
      {
         "op":"add",
         "ref":{
            "type":"roles",
            "tmpId":10000
         },
         "data":{
            "type":"roles",
            "attributes":{
               "name":"testRolesAgain",
               "key":"testRolesAgain"
            }
         }
      },
      {
         "op":"add",
         "ref":{
            "type":"users"
         },
         "data":{
            "type":"users",
            "attributes":{
               "login":"newLogin"
            },
            "relationships":{
               "addresses":{
                  "type":"addresses",
                  "id":"1"
               },
               "roles":[
                  {
                     "type":"roles",
                     "id":"10000"
                  }
               ]
            }
         }
      }
   ]
}

tmpId - is params for operation add, should be unique for all operations.