ddp-client

A modern JS client for Meteor's DDP. Promise-based. Pluggable WebSocket implementation.

Forked from nbento/meteor-ddp / eddflrs/meteor-ddp with the goal of modernizing the source and supporting pluggable websocket implementations like ReconnectingWebSocket.

Differences to original implementation

• Additional arguments to call() and subscribe() don't need to be placed in an array, but are passed varargs style.
• Returned Promises align with standard ES6 Promise spec, i.e. have methods then and catch instead of fail and success when relying on $.Deferred.
• Passing an alternative WebSocket implementation is possible, for example to add reconnection behavior. See constructor example below.
• All code is modern ES6 with a sprinkle of ES7.
• No Oauth support. (If anyone needs that, feel free to send a PR with modern rewrite of original source.)
• Ability to turn off client side collections. Useful when using DDP for easy message passing between server and client.

Dependencies

• a Promise implementation can be provided by babel-polyfill, so when in doubt check and/or include that in your build.

Methods

All methods return promises if it makes sense and not specified otherwise.

• constructor(ws, opts)

// using ws url
const ddp = new DDPClient('ws://yourApp.meteor.com/websocket')
// using particular ws impl
const ddp = new DDPClient(new ReconnectingWebSocket('ws://yourApp.meteor.com/websocket'))

Options

{
    // turns off/on tracking collection documents locally
    // beware that watchers may not get the same data passed in depending on this setting
    // default: true (collection tracking on)
    collections: false
}

• connect()

ddp.connect().then(() => {
  console.log('Connected!')
})

• call(methodName, param1, ...) - Does a Remote Procedure Call on any method exposed through Meteor.methods on the server.

ddp.call('ping', 123, 234).then(res => console.log(res))

• subscribe(subscriptionName, param1, ...) - Subscribes to data published on the server. You can observe changes on a collection by using the 'watch' method. Returned promise is resolved when subscription is ready.

• unsubscribe(subscriptionName) - Unsubscribes to data published on the server. Leaves local collection intact.

• 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 nothing.

ddp.watch('players', (changedDoc, message) => {
  console.log('players collection item changed', changedDoc, message)

  // Was it removed?
  if (message === 'removed') {
    console.log('document removed from local collection!')
  }
})

• 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.

No Oauth support

There is no Oauth support in this release. I do not need it and as such did not invest the effort to bring that code up to date as well.

Acknowledgements

Thanks to Eddie Flores and nbento for the original code!