diff --git a/readme.md b/readme.md index 2d448d7..f86f971 100644 --- a/readme.md +++ b/readme.md @@ -2,233 +2,42 @@ MessageBroker provides framework agnostic, decoupled communication between publishers and subscribers. This library is fully type safe and works in both browsers and Node.js. MessageBroker is built ontop of [RxJS](https://rxjs.dev/guide/overview) providing access to observables and a comprehensive list of operators. -## Installation +Full documentation can be found at http://opensource.morganstanley.com/message-broker/ -```typescript -npm install @morgan-stanley/message-broker -``` - -## TypeScript - -Required Typescript version: >3.4 - -The library depends on TypeScript's support for decorators. Therefore you must enable `experimentalDecorators` and `emitDecoratorMetadata`. - -```json -{ - "compilerOptions": { - "experimentalDecorators": true, - "emitDecoratorMetadata": true - } -} -``` - -## Polyfills - -This library will work with modern browsers and JavaScript run-times without the need for polyfills, however if targeting older browsers you will need to provide a polyfill for the following types. - -* Map - [Read about the Map type here](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) - -This library also makes use of the `reflect-metadata` [API](https://rbuckton.github.io/reflect-metadata/) for performing runtime introspection. Most browsers will not support this therefore you must install this yourself. - -```typescript -npm install reflect-metadata -``` - -And you should import this module at the root of your application. - -```typescript -import "reflect-metadata"; -``` - -## Using the MessageBroker - -An instance of the MessageBroker can be created using the `messagebroker` function. This will return a single instance of the MessageBroker. - -#### Example #### - -```typescript - -import { messagebroker } from "@morgan-stanley/message-broker"; - -const messagebroker = messagebroker(); - -``` -### Subscribing to a channel - -Listening to messages requires a subscription to a channel. Once subscribed any messages published to that channel will be received. Subscribing to a channel is done by calling the `get` function. The `get` function is ideal if you are soley interested in receiving messages. MessageBroker leverages [RxJS](https://rxjs.dev/), the `get` function will return an Observable that can be subscribed to. - -```typescript -import { messagebroker } from "@morgan-stanley/message-broker"; -import { Subscription } from "rxjs"; - -private subscription: Subscription; - -public subscribeToMessages(): void { - this.subscription = messagebroker() - .get('myChannelName') - .subscribe( - message => {}, // Next handler - () => {}, // Error handler - () => {} // Complete handler - ); -} - -// Clean up. -this._subscription.unsubscribe(); - -``` - -### Publishing to a channel - -Publishing messages requires a channel, this can be created using the `create` function. If the channel already exists the existing channel will be returned. Once the channel is created a message can be published using the `publish` function. Passing a payload is optional but if you choose to do so a message type can also be passed for more granular filtering. - -```typescript - -import { messagebroker } from "@morgan-stanley/message-broker"; - -public publishMessage(): void { - - messagebroker() - .create('myChannelName') - .publish( - { data: 'myData'}, // Payload - 'ApplicationEvent' // Message type - ); - } -``` - -### Replay Messages ### - -Replaying will allow new subscriptions to receive the latest "n" number of messages. Using the messagebroker config the user can configure how many messages they want to be cached when subscriptions are made. Configs can only be provided when the messagebroker channels are created. - -```typescript -import { messagebroker } from "@morgan-stanley/message-broker"; - -public publishToCachedChannel(): void { - messagebroker() - .create('myCachedChannel', {replayCacheSize: 2}) // All subscriptions will receive the two most recent messages. - .publish( - { data: 'myData' }, - 'ApplicationEvent' - ); -} - -``` - -It is important to note that creating a channel with the same name but with different configurations will throw an error. - -### Typing the MessageBroker ### - -We recommend typing the messagebroker to avoid unexpected errors during runtime. Typing the messagebroker allows you to specify a contract between the channel name and the payload type that will flow across that channel. This enforces that the types specified on the channel contract must match when using the methods of the messagebroker. If they do not match you will receive compilation errors. - -#### Example #### - -```typescript - -/* Defined our channel contract. */ - export interface IMessageChannels { - 'hello': string; - 'goodbye': undefined; - 'operation1': { foo: string }; - } - - import { messagebroker } from "@morgan-stanley/message-broker"; - - const typedMessageBroker = messagebroker(); - - //Publish - typedMessageBroker.create("operation1").publish({foo: "test"}); // OK - typedMessageBroker.create("operation1").publish({foo: number}); // Error: foo cannot be set to number - typedMessageBroker.create("unknown").publish({foo: "test"}); // Error: invalid channel name - - //Subscribe - typedMessageBroker.get("hello").subscribe(message => console.log(message.data)); // OK: data will be of type string - typedMessageBroker.get("invalid").subscribe(message => console.log(message.data)); // Error: invalid channel name - -``` - -### RSVP ### +## Basic Usage -The rsvp methods allow developers to define a request/response model using the messagebroker. The rsvp (publish) overload is synchronous and will ask all responders to respond to the message payload being provided. - -### RSVP (Publish) ### - -```typescript - -/* Defined our channel contract. */ - export interface IMessageChannels extends IRSVPConfig { - nonRSVPChannel : string; - rsvp: { - myRSVPChannel: { - payload: { data: string }; - response: string[]; - }; - }; - } - - import { messagebroker } from "@morgan-stanley/message-broker"; - - const results = messagebroker().rsvp('myRSVPChannel', { data: 'abcde'}); - -``` - -### RSVP (Respond) ### - -```typescript - -/* Defined our channel contract. */ - export interface IMessageChannels extends IRSVPConfig { - nonRSVPChannel : string; - rsvp: { - myRSVPChannel: { - payload: { data: string }; - response: string[]; - }; - }; - } - - import { messagebroker } from "@morgan-stanley/message-broker"; - - const results = messagebroker().rsvp('myRSVPChannel', payload => { - // Perform some work on payload - split string . - return [...payload]; // Payload and response type enforced by contract. - }); +First, install the message-broker +```bash +npm install @morgan-stanley/message-broker ``` -### RSVP (Respond) with manual disconnect ### +then you can start sending and receiving messages like this ```typescript +import { messagebroker, IMessageBroker } from '@morgan-stanley/message-broker'; -/* Defined our channel contract. */ - export interface IMessageChannels extends IRSVPConfig { - nonRSVPChannel : string; - rsvp: { - myRSVPChannel: { - payload: { data: string }; - response: string[]; - }; +interface IContracts { + myChannel: { + payload: string; }; - } +} - import { messagebroker } from "@morgan-stanley/message-broker"; +const broker: IMessageBroker = messagebroker(); - const results = messagebroker().rsvp('myRSVPChannel', payload => this.doWork(payload)); - - // Manually disconnect the responder to avoid handling further rsvp requests. - responder.disconnect(); +broker.get('myChannel').subscribe((message) => { + console.log(message.payload); +}); +broker.create('myChannel').publish({ + payload: 'My first message using the MessageBroker!', +}); ``` -### Dependency Injection (DI) - -The MessageBroker class is decorated with `@Injectable` from @morgan-stanley/needle. This means that it can be -constructed by different DI frameworks. For more information please refer to the documentation [here](https://github.com/morganstanley/needle "Needle documentation") - ## Development -Here are a list of commands to run if you are interested in developing or contributing to the project. For guidelines on how to contribute please click [here](./CONTRIBUTING.md). +For guidelines on how to contribute please click [here](./CONTRIBUTING.md). +Here are a list of commands to run if you are interested in developing or contributing to the project. ```typescript @@ -246,4 +55,4 @@ npm run watch-build // Run build in watch mode. npm run build-release // Run a full build (Compile, Tests, Lint). -``` \ No newline at end of file +``` diff --git a/site/content/getting-started.mdx b/site/content/getting-started.mdx index f00ecab..adcf8f4 100644 --- a/site/content/getting-started.mdx +++ b/site/content/getting-started.mdx @@ -4,14 +4,14 @@ title: Getting Started --- ```bash -npm install @morganstanley/message-broker +npm install @morgan-stanley/message-broker ``` ```Typescript import { messagebroker, - TypedMessageBroker -} from '@morganstanley/message-broker' + IMessageBroker +} from '@morgan-stanley/message-broker' interface IContracts { myChannel: { @@ -19,14 +19,14 @@ interface IContracts { } } -const messagebroker: TypedMessageBroker +const broker: IMessageBroker = messagebroker(); -messagebroker.get('myChannel').subscribe(message => { +broker.get('myChannel').subscribe(message => { console.log(message.payload) }); -messagebroker.create('myChannel').publish({ +broker.create('myChannel').publish({ payload: 'My first message using the MessageBroker!' }); ```