Use Npm Modules with Your Meteor App
Using With Meteor 1.2
If you are already using
meteorhacks:npm
and want to use Meteor 1.2 for your project. Follow these steps:rm -rf packages/npm-container meteor remove npm-container meteor update meteorhacks:npm meteor
With Meteor you only can use npm
modules inside packages. You can't directly use npm
modules with meteor apps. This package solves that issue :)
Installation
meteor add meteorhacks:npm
Then start your app with meteor
and follow the instructions.
Defining Packages
Once the npm support has been initialized, you'll be having a file name called packages.json
inside your app. Define packages on that file as shown below.
1{ 2 "redis": "0.8.2", 3 "github": "0.1.8" 4}
You must need to define absolute version number of the npm module
If you need to install an npm module from a specific commit, use the syntax:
1{ 2 "googleapis": "https://github.com/bradvogel/google-api-nodejs-client/archive/d945dabf416d58177b0c14da64e0d6038f0cc47b.tar.gz" 3}
Using Packages
You can use Meteor.npmRequire
method to access the npm module on server side and use it as you want.
Most of the npm modules provide asynchronous API's with callbacks or promises. So, you can't directly use them with Meteor. Because of that, this package comes with a handy set of Async utilities make your life easier.
Example on using npm module inside a Meteor method
1if (Meteor.isClient) { 2 getGists = function getGists(user, callback) { 3 Meteor.call('getGists', user, callback); 4 } 5} 6 7if (Meteor.isServer) { 8 Meteor.methods({ 9 'getGists': function getGists(user) { 10 var GithubApi = Meteor.npmRequire('github'); 11 var github = new GithubApi({ 12 version: "3.0.0" 13 }); 14 15 var gists = Async.runSync(function(done) { 16 github.gists.getFromUser({user: 'arunoda'}, function(err, data) { 17 done(null, data); 18 }); 19 }); 20 21 return gists.result; 22 } 23 }); 24}
API
Available in the Server Side only
Meteor.npmRequire(npmModuleName)
This method loads NPM modules you've specified in the packages.json
file.
1var Github = Meteor.npmRequire('github');
Meteor.require(npmModuleName)
Same as above. But deprecated.
Async Utilities
Available in the Server Side only Async Utitlies is available as a separate package via
meteorhacks:async
Meteor APIs are executed synchronously. Most of the NodeJS modules works asynchronously. So we need a way to bride the gap. Async Utilities comes to rescue you.
Async.runSync(function)
Async.runSync()
pause the execution until you invoke done()
callback as shown below.
1var response = Async.runSync(function(done) { 2 setTimeout(function() { 3 done(null, 1001); 4 }, 100); 5}); 6 7console.log(response.result); // 1001
done()
callback takes 2 arguments. error
and the result
object. You can get them as the return value of the Async.runSync()
as shown as response in the above example.
return value is an object and it has 2 fields. error
and result
.
Meteor.sync(function)
Same as Async.runSync
but deprecated.
Async.wrap(function)
Wrap an asynchronous function and allow it to be run inside Meteor without callbacks.
1 2//declare a simple async function 3function delayedMessge(delay, message, callback) { 4 setTimeout(function() { 5 callback(null, message); 6 }, delay); 7} 8 9//wrapping 10var wrappedDelayedMessage = Async.wrap(delayedMessge); 11 12//usage 13Meteor.methods({ 14 'delayedEcho': function(message) { 15 var response = wrappedDelayedMessage(500, message); 16 return response; 17 } 18});
If the callback has a result, it will be returned from the wrapped function. If there is an error, it will be thrown.
Async.wrap(function)
is very similar toMeteor._wrapAsync
.
Async.wrap(object, functionName)
Very similar to Async.wrap(function)
,
but this API can be used to wrap an instance method of an object.
1var github = new GithubApi({ 2 version: "3.0.0" 3}); 4 5//wrapping github.user.getFrom 6var wrappedGetFrom = Async.wrap(github.user, 'getFrom');
Async.wrap(object, functionNameList)
Very similar to Async.wrap(object, functionName)
,
but this API can be used to wrap multiple instance methods of an object.
1var github = new GithubApi({ 2 version: "3.0.0" 3}); 4 5//wrapping github.user.getFrom and github.user.getEmails 6var wrappedGithubUser = Async.wrap(github.user, ['getFrom', 'getEmails']); 7 8//usage 9var profile = wrappedGithubUser.getFrom('arunoda'); 10var emails = wrappedGithubUser.getEmails();