README.md

Meteor-DDP

A promise-based Meteor DDP client for version pre1 introduced in Meteor 0.5.7.

Dependencies

• jQuery 1.5+ (Uses $.Deferred)

Methods

• connect() - Starts a WebSocket connection and lets the server know we're about to talk some DDP. Returns -> Promise which resolves on succesful connection.

var ddp = new MeteorDdp('ws://yourApp.meteor.com/websocket');
ddp.connect().done(function() {
  console.log('Connected!');
});

• call(methodName, [params, ...]) - Does a Remote Procedure Call on any method exposed through Meteor.methods on the server. Returns -> Promise which resolves with any returned data.

/* Lets say we can RPC a createPlayer method which returns a playerId. Lets also say 
   that we need the playerId in order to join a game (via a joinGame method 
   which returns a gameId). Here's a couple of ways to do this with promises: 
*/

// Using the done method...
var createPlayer = ddp.call('createPlayer');
createPlayer.done(function(playerId) {
  var joinGame = ddp.call('joinGame', [playerId]);
  joinGame.done(function(gameId) {
    console.log("We joined a game, here's the game id: ", gameId);
  });
});

// We can pipe it... (Note: pipe is deprecated as of jQuery 1.8)
var createPlayer = ddp.call('createPlayer');
var joinGame = createPlayer.pipe(function(playerId) {
  return ddp.call('joinGame', [playerId]);
});
joinGame.done(function(gameId) {
  console.log('We joined a game: ', gameId);
});

// We can use when...then...
$.when(ddp.call('createPlayer')).then(function(playerId) {
  ddp.call('joinGame', [playerId]).done(function(gameId) {
    console.log('We joined a game! Game id: ', gameId);
  });
});

• subscribe(subscriptionName, [params, ...]) - Subscribes to data published on the server. You can observe changes on a collection by using the 'watch' method. Returns -> Promise which resolves on successful subscription and fails otherwise.

// Subscribing returns a promise which resolved on success, but 
// you probably only care if the subscription fails...
ddp.subscribe('plyers', [gameId]).fail(function(err) {
  console.log('We actually wanted to subscribe to players not plyers...');
});

• unsubscribe(subscriptionName) - Unsubscribes to data published on the server. Leaves local collection intact. Returns -> Promise which resolves on successful unsubscription and fails if something went wrong in the process or subscription never existed.

var unsubPlayers = ddp.unsubscribe('players');
unsubPlayers.done(function() {
  console.log("Successfully unsubscribed to players");
});
unsubPlayers.fail(function(err) {
  console.log("Something went wrong, couldn't unsub players. ", err);
});

• watch(collectionName, callback) - Observe a collection and be notified whenever that collection changes via your callback. A copy of the modified document will be sent as argument to the callback. Returns -> void

// So say we subscribed to the `players` collection and want to be notified when any change occurs:
ddp.watch('players', function(changedDoc) {
  console.log("The players collection changed. Here's what changed: ", changedDoc);

  // Was it deleted?
  if (changedDoc.__wasDeleted) {
    console.log("This document doesn't exist in our collection anymore :(");
  }

});

• getCollection(collectionName) - Returns -> An Object containing the locally stored collection.

ddp.getCollection('rooms'); // -> {id1: {document1}, id2: {document2}, ...}

• getDocument(collectionName, documentId) - Returns -> The document with specified documentId belonging to collectionName.

ddp.getDocument('rooms', '4ec81e1b-2e16-42f4-a915-cc18ad7bdb0c') // -> {document}

• close() - Closes the WebSocket connection. Returns -> void

ddp.close(); // yeah...