What is actionhero?
vsa-server.js is a multi-transport Node.JS API Server with integrated cluster capabilities and delayed tasks.
What does that mean?
In actionhero, you make actions which respond to client requests.
{% highlight javascript %}
// actionhero generateAction --name=randomNumber
// File: actions/randomNumber.js
exports.randomNumber = {
name: 'randomNumber',
description: 'I am an API method which will generate a random number',
outputExample: {
randomNumber: 0.123
},
run: function(api, data, next){
data.response.randomNumber = Math.random();
next();
}
};
{% endhighlight %}
These actions don't just work for the web, they work for all sorts of clients.
Web
{% highlight bash %}
> curl localhost:8080/api/randomNumber
{
"randomNumber": 0.8158452461939305
}
{% endhighlight %}
Socket
{% highlight bash %}
> telnet localhost 5000
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
{"welcome":"Hello! Welcome to the actionhero api","context":"api"}
randomNumber
{"randomNumber":0.7903316407464445,"context":"response","messageCount":1}
{% endhighlight %}
WebSocket
{% highlight javascript %}
var client = new ActionheroClient;
client.connect(function(error, details){
client.action("randomNumber", function(data){
alert(data.randomNumber);
});
});
{% endhighlight %}
actionhero also lets you perform tasks in the background...
{% highlight javascript %}
// actionhero generateTask --name=sendEmail
// File: tasks/sendEmail.js
exports.task = {
name: 'sendEmail',
description: 'send an email to users after they sign up'
queue: 'default',
frequency: 0,
run: function(api, params, next){
// email sending stub
api.users.sendEmail(params.userId, function(error, done){
next(error);
});
});
};
{% endhighlight %}
... and you can invoke the task from anywhere in the framework, including actions.
{% highlight javascript %}
// api.tasks.enqueue(nameOfTask, args, queue, callback)
api.tasks.enqueue("sendEmail", {to: 'evan@evantahler.com'}, 'default', function(err, toRun){
// enqueued!
});
{% endhighlight %}
actionhero enables clients to talk to each other.
{% highlight javascript %}
// client 1
var client1 = new ActionheroClient;
client1.connect(function(error, details){
client1.roomAdd("myChatRoom", function(err){
client1.say('myChatRoom', 'hello from client 1');
});
});
// client 2
var client2 = new ActionheroClient;
client2.connect(function(error, details){
client2.roomAdd("myChatRoom", function(err){
client2.on('say', function(message){
console.log(message);
});
});
});
{% endhighlight %}
actionhero can do all of this, and it can work on one server or hundreds (actionhero is cluster-ready from the get-go).
{% highlight bash %}
# start 1 instance
./node_modules/.bin/actionhero start
# start a cluster
./node_modules/.bin/actionhero startCluster
{% endhighlight %}