rbbt-client v0.5.1

RBBTClient

RBBTClient is a JavaScript library designed for seamless interaction with RabbitMQ over WebSockets. It offers a simple and intuitive API for connecting to RabbitMQ brokers, managing exchanges and subscribing to queues.

Installation

To install the rbbt-client package, use npm:

npm install rbbt-client

Usage

Here's a basic example of how to use RBBTClient:

import { RBBTClient } from "rbbt-client";
// Initialize the RBBTClient: Stomp URL, vhost, username, password
const rbbt = new RBBTClient("ws://localhost:15674/ws", "/", "guest", "guest");
// The default stomp port is 15674, please don't make the same mistakes I made that lead to this package
// Connect to the RabbitMQ broker
const conn = rbbt.connect();
// Create a new channel
const ex = conn.exchange("amq.direct");
// Create a new exclusive queue
const q = ex.queue("", { exclusive: true });
// Bind the queue with a routing key
q.bind("test");
// Subscribe to the queue
q.subscribe({ noAck: true }, (msg) => {
  console.log(msg);
});

API

RBBTClient

Constructor: new RBBTClient(url, vhost, username, password, name?)

• url: The WebSocket URL of the RabbitMQ broker (e.g., "ws://localhost:15674/ws").
• vhost: The virtual host to connect to (default: "/").
• username: The username for authentication (default: "guest").
• password: The password for authentication (default: "guest").
• name?: Optional name for the client instance.

Methods

• connect()

  • Establishes a connection to the RabbitMQ broker using the provided credentials.
  • Returns the RBBTClient instance for chaining further calls.
  • Example:

    const conn = rbbt.connect();

• close()

  • Closes the connection to the RabbitMQ broker.
  • Example:

    conn.close();

• exchange(name, options)

  • Creates or retrieves an exchange by its name.
  • Parameters:
    • name: The name of the exchange. If omitted, an automatically generated name is used.
    • options: The exchange options (default: {}).
  • Returns: An RBBTExchange object.
  • Example:

    const ex = conn.exchange("amq.direct");

• debug(msg)

  • A function that can be overridden to log debug messages.
  • Example:

    conn.debug = (msg) => console.log(msg);

RBBTError

Constructor: new RBBTError(message, connection)

• message: A string describing the error.
• connection: The RBBTClient instance that encountered the error.

RBBTError is a custom error class used throughout the RBBTClient library to handle client-specific errors.

Example:

try {
  throw new RBBTError("Invalid connection", rbbt);
} catch (err) {
  console.error(err.message); // "Invalid connection"
}

RBBTExchange

Constructor: new RBBTExchange(connection, name, options?)

• connection: The RBBTClient instance used for the connection.
• name: The name of the exchange. If not provided, a unique name will be generated (default: "").
• options?: Optional parameters to configure the exchange:
  • passive: Whether the exchange is passive (default: false).
  • durable: Whether the exchange is durable (default: false).
  • autoDelete: Whether the exchange should auto-delete (default: false).
  • internal: Whether the exchange is internal (default: false).

Properties

• connection: The associated RBBTClient instance.
• name: The name of the exchange.
• watch: The watch subscription for the exchange.
• helper: An instance of RBBTHelpers.
• queues: The list of queues associated with the exchange.
• closed: A boolean indicating whether the exchange is closed (default: false).
• options: The options used to configure the exchange.

Methods

• open()

  • Opens the exchange by subscribing to it and watching for messages.
  • Throws an error if the client is not connected.
  • Example:

    const exchange = new RBBTExchange(connection, "myExchange");

• close()

  • Closes the exchange by unsubscribing from the watch and marking it as closed.
  • Example:

    exchange.close();

• send(body, routingKey, properties?)

  • Sends a message to the exchange with the specified body, routingKey, and optional properties.
  • Parameters:
    • body: The message body (can be a string or Uint8Array).
    • routingKey: The routing key for the message.
    • properties: Additional message properties (default: {}).
  • Example:

    exchange.send("Hello, World!", "myRoutingKey");

• subscribe(callback, { noAck, exclusive })

  • Subscribes to the exchange and receives messages, triggering the provided callback function.
  • Parameters:
    • callback: The function to handle the received messages (message: RBBTMessage).
    • noAck: Whether to automatically acknowledge messages (default: false).
    • exclusive: Whether the subscription is exclusive (default: false).
  • Example:

    exchange.subscribe((msg) => {
      console.log("Received message:", msg.body);
    });

• unsubscribe()

  • Unsubscribes from the exchange and stops receiving messages.
  • Example:

    exchange.unsubscribe();

• queue(queueName, options?)

  • Returns a queue associated with the exchange, creating it if necessary.
  • Parameters:
    • queueName: The name of the queue (default: "").
    • options: Queue options such as passive, durable, autoDelete, and exclusive.
  • Example:

    const queue = exchange.queue("myQueue", { durable: true });

RBBTMessage

Constructor: new RBBTMessage(exchange)

• exchange: The RBBTExchange object associated with the message.

The RBBTMessage class represents a message sent or received from an exchange or queue. It contains properties and the message body.

Properties:

• exchange: The exchange where the message was published.
• routingKey: The routing key used for message delivery (default: "").
• properties: A collection of message properties (headers, delivery mode, etc.).
• bodySize: The size of the message body (default: 0).
• body: The message content, which can be a Uint8Array, string, or null.
• redelivered: A flag indicating if the message was redelivered (default: false).

Example:

const message = new RBBTMessage(exchange);
message.body = "Hello, world!";
console.log(message.body); // Output: "Hello, world!"

RBBTQueue

Constructor: new RBBTQueue(exchange, name, options?)

• exchange: The RBBTExchange instance associated with the queue.
• name: The name of the queue. If not provided, a unique name will be generated (default: "").
• options?: Optional parameters to configure the queue:
  • passive: Whether the queue should be passive (default: false).
  • durable: Whether the queue should be durable (default: true for non-empty names, false for empty names).
  • autoDelete: Whether the queue should auto-delete when no consumers are connected (default: true for empty names, false for non-empty names).
  • exclusive: Whether the queue should be exclusive (default: true for empty names, false for non-empty names).

Methods

• create()

  • Creates the queue if the connection client is active and the exchange is not closed.
  • Example:

    const q = new RBBTQueue(ex, "myQueue");

• bind(routingKey?)

  • Binds the queue to an exchange with the given routingKey. If the queue is already bound, the binding is updated.
  • Parameters:
    • routingKey: The routing key for binding (default: "").
  • Example:

    q.bind("routing.key");

• unbind(routingKey?)

  • Unbinds the queue from an exchange with the given routingKey.
  • Parameters:
    • routingKey: The routing key for unbinding (default: "").
  • Example:

    q.unbind("routing.key");

• subscribe(options, callback)

  • Subscribes to the queue for receiving messages. A callback is triggered on each new message.
  • Parameters:
    • options: Subscription options:
      • noAck: Whether to acknowledge messages automatically (default: true).
      • exclusive: Whether the subscription is exclusive (default: false).
      • tag: A custom tag for the subscription (default: "").
      • args: Additional arguments for the subscription (default: {}).
    • callback: The function to handle the received messages (msg: RBBTMessage).
  • Example:

    q.subscribe({ noAck: false }, (msg) => {
      console.log(msg.body);
    });

• unsubscribe()

  • Unsubscribes from the queue and stops receiving messages.
  • Example:

    q.unsubscribe();

• send(body, properties?)

  • Sends a message to the queue with the specified body and properties.
  • Parameters:
    • body: The message body (can be a string or Uint8Array).
    • properties: Additional message properties (default: {}).
  • Example:

    q.send("Hello, World!", { priority: 1 });

Types

RBBTQueueParams

Defines the parameters for queue configuration.

• passive: (optional) If true, the queue must already exist (default: false).
• durable: (optional) If true, the queue will survive server restarts (default: true if name is provided, otherwise false).
• autoDelete: (optional) If true, the queue will automatically delete itself when no longer in use (default: true if name is not provided).
• exclusive: (optional) If true, the queue is exclusive to the connection (default: true if name is not provided).

type RBBTQueueParams = {
  passive?: boolean;
  durable?: boolean;
  autoDelete?: boolean;
  exclusive?: boolean;
};

RBBTConsumeParams

Defines the parameters for consuming messages from a queue.

• tag: (optional) A consumer tag to identify the consumer.
• noAck: (optional) If true, messages are automatically acknowledged (default: true).
• exclusive: (optional) If true, the consumer is exclusive (default: false).
• args: (optional) Additional arguments for the consumer.

export type RBBTConsumeParams = {
  tag?: string;
  noAck?: boolean;
  exclusive?: boolean;
  args?: Record<string, any>;
};

RBBTProperties

Defines the message properties that can be set on a published message.

• headers: (optional) Custom headers for the message, as key-value pairs.
• messageId: (optional) A unique identifier for the message.

export type RBBTProperties = {
  headers?: Record<string, any>;
  messageId?: string;
};

RBBTExchangeParams

Defines the parameters for exchange configuration.

• passive: (optional) If true, the exchange must already exist (default: false).
• durable: (optional) If true, the exchange will survive server restarts (default: false).
• autoDelete: (optional) If true, the exchange will be deleted when no longer in use (default: false).
• internal: (optional) If true, the exchange is used only for internal message routing (default: false).
• args: (optional) Additional arguments for the exchange, passed as key-value pairs.

export type RBBTExchangeParams = {
  passive?: boolean;
  durable?: boolean;
  autoDelete?: boolean;
  internal?: boolean;
  args?: Record<string, any>;
};

Example

Below is a full example demonstrating how to set up a connection, create a channel, declare a queue, bind it to an exchange, and start receiving messages:

import { RBBTClient } from "rbbt-client";

const rbbt = new RBBTClient("ws://localhost:15674/ws", "/", "guest", "guest");

// Step 2: Connect to RabbitMQ
const connection = rbbt.connect();

// Step 3: Create an exchange (this is where messages will be sent)
const exchange = connection.exchange("my.direct.exchange", {
  durable: true, // The exchange will survive server restarts
});

// Step 4: Create a queue (this is where messages will be received)
const queue = exchange.queue("my.queue", {
  durable: true, // The queue will survive server restarts
});

// Step 5: Bind the queue to the exchange using a routing key
queue.bind("my.routing.key");

// Step 6: Publish a message to the exchange
exchange.send("Hello RabbitMQ!", "my.routing.key");

// Step 7: Subscribe to the queue to receive messages
queue.subscribe(
  {
    noAck: false,
  },
  (message) => {
    console.log("Received message:", message.body); // Display the message body in the console
  },
);