@sourceloop/chat-service

chat-service

Overview

A microservice designed to facilitate real-time communication between users and user groups. It provides a scalable and modular solution for handling both individual and group chat functionalities.

Installation

npm i @sourceloop/chat-service

Usage

Using with Sequelize

This service supports Sequelize as the underlying ORM using @loopback/sequelize extension. And in order to use it, you'll need to do following changes.

1.To use Sequelize in your application, add following to application.ts:

this.bind(ChatServiceBindings.Config).to({
  useCustomSequence: false,
  useSequelize: true,
});

2. Use the SequelizeDataSource in your audit datasource as the parent class. Refer this for more.

Implementation

Create a new Application using Loopback CLI and add the Component for ChatService in application.ts

import {BootMixin} from '@loopback/boot';
import {ApplicationConfig} from '@loopback/core';
import {RepositoryMixin} from '@loopback/repository';
import {RestApplication} from '@loopback/rest';
import {
  RestExplorerBindings,
  RestExplorerComponent,
} from '@loopback/rest-explorer';
import {ServiceMixin} from '@loopback/service-proxy';
import {ChatServiceComponent} from '@sourceloop/chat-service';
import path from 'path';
import {MySequence} from './sequence';

export {ApplicationConfig};

export class ChatApplication extends BootMixin(
  ServiceMixin(RepositoryMixin(RestApplication)),
) {
  constructor(options: ApplicationConfig = {}) {
    super(options);

    // Set up the custom sequence
    this.sequence(MySequence);

    // Set up default home page
    this.static('/', path.join(__dirname, '../public'));

    // Customize @loopback/rest-explorer configuration here
    this.configure(RestExplorerBindings.COMPONENT).to({
      path: '/explorer',
    });
    this.component(RestExplorerComponent);

    // add Component for ChatService
    this.component(ChatServiceComponent);

    this.projectRoot = __dirname;
    // Customize @loopback/boot Booter Conventions here
    this.bootOptions = {
      controllers: {
        // Customize ControllerBooter Conventions here
        dirs: ['controllers'],
        extensions: ['.controller.js'],
        nested: true,
      },
    };
  }
}

Environment Variables

Name	Required	Default Value	Description
NODE_ENV	Y		Node environment value, i.e. dev, test, prod
LOG_LEVEL	Y		Log level value, i.e. error, warn, info, verbose, debug
DB_HOST	Y		Hostname for the database server.
DB_PORT	Y		Port for the database server.
DB_USER	Y		User for the database.
DB_PASSWORD	Y		Password for the database user.
DB_DATABASE	Y		Database to connect to on the database server.
DB_SCHEMA	Y		Database schema used for the data source. In PostgreSQL, this will be public unless a schema is made explicitly for the service.
JWT_SECRET	Y		Symmetric signing key of the JWT token.
JWT_ISSUER	Y		Issuer of the JWT token.

Setting up DataSource

Here is a sample Implementation DataSource implementation using environment variables and PostgreSQL as the data source.

import {inject, lifeCycleObserver, LifeCycleObserver} from '@loopback/core';
import {juggler} from '@loopback/repository';

const config = {
  name: 'chatDb',
  connector: 'postgresql',
  url: '',
  host: process.env.DB_HOST,
  port: process.env.DB_PORT,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
  database: process.env.DB_DATABASE,
  schema: process.env.DB_SCHEMA,
};

@lifeCycleObserver('datasource')
export class ChatDataSource
  extends juggler.DataSource
  implements LifeCycleObserver
{
  static dataSourceName = 'chatDb';
  static readonly defaultConfig = config;

  constructor(
    // You need to set datasource configuration name as 'datasources.config.Chat' otherwise you might get Errors
    @inject('datasources.config.Chat', {optional: true})
    dsConfig: object = config,
  ) {
    super(dsConfig);
  }
}

Migrations

The migrations required for this service are processed during the installation automatically if you set the CHAT_MIGRATION or SOURCELOOP_MIGRATION env variable. The migrations use db-migrate with db-migrate-pg driver for migrations, so you will have to install these packages to use auto-migration. Please note that if you are using some pre-existing migrations or databasea, they may be affected. In such a scenario, it is advised that you copy the migration files in your project root, using the CHAT_MIGRATION_COPY or SOURCELOOP_MIGRATION_COPY env variables. You can customize or cherry-pick the migrations in the copied files according to your specific requirements and then apply them to the DB.

Additionally, there is now an option to choose between SQL migration or PostgreSQL migration. NOTE: For @sourceloop/cli users, this choice can be specified during the scaffolding process by selecting the "type of datasource" option.

API Documentation

Common Headers

Authorization: Bearer where is a JWT token signed using JWT issuer and secret. Content-Type: application/json in the response and in request if the API method is NOT GET

Common Request path Parameters

{version}: Defines the API Version

Common Responses

200: Successful Response. Response body varies w.r.t API 401: Unauthorized: The JWT token is missing or invalid 403: Forbidden : Not allowed to execute the concerned API 404: Entity Not Found 400: Bad Request (Error message varies w.r.t API) 201: No content: Empty Response

API Details

Visit the OpenAPI spec docs