README.md

LWC OSS App Using gRPC Server

• Start with npm install - to install all dependencies

  • Breakdown of the dependencies installed below :
  • run npm i - npm install
    • grpc - main library for grpc
    • @grpc/proto-loader - handle protobuffers
    • express-sse - for server sent events push to client app
    • jsforce - Connection to Salesforce
    • dotenv- Storing parameters used for the connection to Salesforce Connected App option

Set up your Salesforce org credential

• Setup your Org Credentials inside a new .env file as mentioned below.
• Create a .env file with your salesforce org credentials :

    USERNAME=<<YOUR USER NAME>>   
    PASSWORD=<<YOUR PASSWORD>>   
    SECURITY_TOKEN=<<YOUR SECURITY TOKEN>>   
    LOGIN_URL=https://CS18.salesforce.com   
    INSTANCE_URL=https://XXXX-dev-ed.cs110.my.salesforce.com   
    CLIENT_KEY=<<YOUR CLIENT KEY>>   
    CLIENT_SECRET=<<YOUR CLIENT SECRET>>   
    REDIRECT_URL=http://localhost:3001/callback   

• Use the node scripts npm run build OR npm run build:development to build the dist folder for this app and to include SLDS inside your project.
• Run npm run watch or yarn watch - to view the app.
• View on your port - by default http://localhost:3001 for DEV and http://localhost:5000 for production.

Express JS Endpoints configuration

Main configuration is on the server/main.js file

• /api/v1/stream - using express-sse in order to push events to app.
• /api/v1/subscribe - will log in to Salesforce and will try to subscribed to channel given from the app.
• /api/v1/unsubscribe - Will logout from Salesforce.
• /api/v1/publish - will publish a Platform Event with message given from the app.
• /api/v1/events/all - will get all stored events on server.

gRPC Proto Schema definition

• Inside server/services/salesforce - you'll find all the files that setup this as a micro-service.
• salesforce.proto - One interface that can Subscribe, Publish and more...
• server.js - our gRPC server - that will encode and decode our payloads.
• client.js - our gRPC client that communicate between our Express server to our gRPC Server.

syntax = "proto3";

service SalesforceService {
    // Salesforce API Operations
    rpc ConnectOrg (ConnectRequest) returns (ConnectedOrg) {}
    rpc Subscribe (SubscribeRequest) returns (stream SubscribeResponse) {}
    rpc UnSubscribe (Empty) returns (SubscribeResponse) {}
    rpc PublishEvent (PublishRequest) returns (PublishResponse) {}
    rpc getAllEvents (Empty) returns (stream SubscribeResponse) {}
}

• Each Request and response has a Schema defition strongly typed using protobuffer.

• Example Request payload for connecting to salesforce

  message ConnectRequest {
      string username = 1;
      string password = 2;
      string securityToken = 3;
      string instanceUrl = 4;
      string accessToken = 5;
  }

Start our gRPC server

const PROTO_PATH = __dirname + "/salesforce.proto";

const grpc = require("grpc");
const protoLoader = require("@grpc/proto-loader");

const packageDefinition = protoLoader.loadSync(PROTO_PATH, {
    keepCase: true,
    longs: String,
    enums: String,
    arrays: true
});

const protoPackage = grpc.loadPackageDefinition(packageDefinition);

// Connected Services running
const server = new grpc.Server();
const GRPC_PORT = `127.0.0.1:30047`;
server.addService(protoPackage.SalesforceService.service, {
    "ConnectOrg": ConnectOrg,
    "getAllEvents": getAllEvents,
    "PublishEvent": PublishEvent,
    "Subscribe": Subscribe,
    "UnSubscribe": UnSubscribe
});
server.bind(GRPC_PORT, grpc.ServerCredentials.createInsecure());
console.log(`🔥 GRPC Server is running at http://${GRPC_PORT}`);

server.start();

Start our gRPC client

const PROTO_PATH =  __dirname + "/salesforce.proto";

const grpc = require("grpc");
const protoLoader = require("@grpc/proto-loader");

const packageDefinition = protoLoader.loadSync(PROTO_PATH, {
    keepCase: false,
    longs: String,
    enums: String,
    arrays: true
});

const SalesforceService = grpc.loadPackageDefinition(packageDefinition).SalesforceService;

const clientSF =  new SalesforceService(`localhost:30047`,
        grpc.credentials.createInsecure()
    );

module.exports = clientSF;