A callback style DDP (Meteor's Distributed Data Protocol) node client, originally based alansikora's node-js_ddp-client and Meteor's python client. Uses a more callback style approach.
The client implements version 1 of DDP, as well as fallbacks to pre1 and pre2.
npm install ddp
Built-in authentication support was removed in ddp 0.7.0 due to changes in Meteor version 0.8.2.
One can authenticate using plain-text logins as follows:
// logging in with e-mail
ddpclient.call("login", [
{ user : { email : "user@domain.com" }, password : "password" }
], function (err, result) { ... });
// logging in with username
ddpclient.call("login", [
{ user : { username : "username" }, password : "password" }
], function (err, result) { ... });
You can also use vsivsi/ddp-login.
Please see the example in examples/example.js
. Or here for reference:
var DDPClient = require("ddp");
var ddpclient = new DDPClient({
// All properties optional, defaults shown
host : "localhost",
port : 3000,
path : "websocket",
ssl : false,
autoReconnect : true,
autoReconnectTimer : 500,
maintainCollections : true,
ddpVersion : '1' // ['1', 'pre2', 'pre1'] available
});
/*
* Connect to the Meteor Server
*/
ddpclient.connect(function(error, wasReconnect) {
// If autoReconnect is true, this callback will be invoked each time
// a server connection is re-established
if (error) {
console.log('DDP connection error!');
return;
}
if (wasReconnect) {
console.log('Reestablishment of a connection.');
}
console.log('connected!');
setTimeout(function () {
/*
* Call a Meteor Method
*/
ddpclient.call(
'deletePosts', // name of Meteor Method being called
['foo', 'bar'], // parameters to send to Meteor Method
function (err, result) { // callback which returns the method call results
console.log('called function, result: ' + result);
},
function () { // callback which fires when server has finished
console.log('updated'); // sending any updated documents as a result of
console.log(ddpclient.collections.posts); // calling this method
}
);
}, 3000);
/*
* Call a Meteor Method while passing in a random seed.
* Added in DDP pre2, the random seed will be used on the server to generate
* repeatable IDs. This allows the same id to be generated on the client and server
*/
var Random = require("ddp-random"),
random = Random.createWithSeeds("randomSeed"); // seed an id generator
ddpclient.callWithRandomSeed(
'createPost', // name of Meteor Method being called
[{ _id : random.id(), // generate the id on the client
body : "asdf" }],
"randomSeed", // pass the same seed to the server
function (err, result) { // callback which returns the method call results
console.log('called function, result: ' + result);
},
function () { // callback which fires when server has finished
console.log('updated'); // sending any updated documents as a result of
console.log(ddpclient.collections.posts); // calling this method
}
);
/*
* Subscribe to a Meteor Collection
*/
ddpclient.subscribe(
'posts', // name of Meteor Publish function to subscribe to
[], // any parameters used by the Publish function
function () { // callback when the subscription is complete
console.log('posts complete:');
console.log(ddpclient.collections.posts);
}
);
/*
* Observe a collection.
*/
var observer = ddpclient.observe("posts");
observer.added = function(id) {
console.log("[ADDED] to " + observer.name + ": " + id);
};
observer.changed = function(id, oldFields, clearedFields, newFields) {
console.log("[CHANGED] in " + observer.name + ": " + id);
console.log("[CHANGED] old field values: ", oldFields);
console.log("[CHANGED] cleared fields: ", clearedFields);
console.log("[CHANGED] new fields: ", newFields);
};
observer.removed = function(id, oldValue) {
console.log("[REMOVED] in " + observer.name + ": " + id);
console.log("[REMOVED] previous value: ", oldValue);
};
setTimeout(function() { observer.stop() }, 6000);
});
/*
* Useful for debugging and learning the ddp protocol
*/
ddpclient.on('message', function (msg) {
console.log("ddp message: " + msg);
});
/*
* Close the ddp connection. This will close the socket, removing it
* from the event-loop, allowing your application to terminate gracefully
*/
ddpclient.close();
/*
* If you need to do something specific on close or errors.
* You can also disable autoReconnect and
* call ddpclient.connect() when you are ready to re-connect.
*/
ddpclient.on('socket-close', function(code, message) {
console.log("Close: %s %s", code, message);
});
ddpclient.on('socket-error', function(error) {
console.log("Error: %j", error);
});
/*
* You can access the EJSON object used by ddp.
*/
var oid = new ddpclient.EJSON.ObjectID();
The node DDP client does not implement ordered collections, something that while in the DDP spec has not been implemented in Meteor yet.
Many thanks to Alan Sikora for the ddp-client which formed the inspiration for this code.
Contributions:
- Tom Coleman (@tmeasday)
- Thomas Sarlandie (@sarfata)
- Mason Gravitt (@emgee3)
- Mike Bannister (@possiblities)
- Chris Mather (@eventedmind)
- James Gill (@jagill)
- Vaughn Iverson (@vsivsi)