Introduction
Welcome to the documentation for the MeteorDDP package! This package allows you to create WebSocket connections and communicate with Meteor servers over the DDP (Distributed Data Protocol) protocol. It provides a simple and efficient way to build real-time applications in Meteor.
Requirements
- Meteor framework installed
- Basic knowledge of JavaScript
Installation
To install the MeteorDDP package, follow these steps:
- Open your terminal.
- Navigate to your Meteor project directory.
- Run the following command:
meteor add meteorddp
Usage
Basic Connection
To establish a basic connection to a Meteor server, follow these steps:
- Create a new instance of the DDP class.
- Call the `connect` method on the DDP instance, passing in the server URL as a parameter.
- Handle the different connection events, such as ‘connected’, ‘failed’, or ‘disconnected’, using event listeners.
// Import necessary libraries
import { DDP } from 'meteorddp';
// Create a new instance of DDP
const ddp = new DDP();
// Connect to the Meteor server
ddp.connect('ws://your-server-url');
// Event listeners for connection events
ddp.on('connected', () => {
// Code to execute when connected to the server
});
ddp.on('failed', (error) => {
// Code to execute when the connection fails
});
ddp.on('disconnected', () => {
// Code to execute when disconnected from the server
});
Sending and Receiving Data
Once connected to the Meteor server, you can send and receive data using DDP methods and subscriptions. Here’s an example:
- Call the `call` method on the DDP instance to send a method call to the server.
- Pass the method name and any required parameters as arguments.
- Handle the server’s response using the callback passed as an argument to the `call` method.
// Call a method on the server
ddp.call('methodName', parameter1, parameter2, (error, result) => {
if (error) {
// Handle error
} else {
// Handle result
}
});
- Call the `subscribe` method on the DDP instance to subscribe to a publication on the server.
- Pass the publication name and any required parameters as arguments.
- Handle the received data using the callback passed as an argument to the `subscribe` method.
// Subscribe to a publication on the server
ddp.subscribe('publicationName', parameter1, parameter2, (error) => {
if (error) {
// Handle error
} else {
// Handle received data
const data = ddp.collections.collectionName.find().fetch();
}
});
Conclusion
Congratulations! You now have a basic understanding of using the MeteorDDP package to establish WebSocket connections and communicate with Meteor servers over the DDP protocol. Explore the different methods and subscriptions available to build powerful real-time applications.