Please more examples!

[giacecco]

Dear dominctarr,
Thank you for your work with event-stream, I have been using it for a few days now but still feel like I am just scraping the surface. There are things that I am sure are feasible using event-stream, but the documentation is not sufficient for me to understand how to put the pieces together. Please provide more examples with it!

My current issue in particular is that I need to transform a series of 'events' into a readable stream. The code should look something like the one below, where 'Emitter' is the constructor for a third-party object calling the function I give as a parameter every time there is new data to process.

var outStream = require('fs').createWriteStream("foo.txt", { 'encoding': 'utf-8' });
var inStream = require('event-stream').????;
var emitter = new Emitter(function (data) {
    // there's new data to push as part of the readable stream!
    inStream.????(data);
});
inStream.pipe(outStream);

Can you give me a hint? Thanks,

Giacecco

[timoxley]

@giacecco you can just write to the destination stream directly

e.g.

emitter.on('data', function(data) {
   destination.write(data)
})

[giacecco]

Ok but which of event-stream's objects is ideal for 'destination', considering that the event generates data in many events? Moreover, I guess I need to use .pause() and .resume() between one event and another if I want destination to understand that the input stream has not finished, or I did not get how that works too?

In general, if not by experimenting with streams, what can one learn about it before fiddling with event-stream? This info would be useful to be at the top of the README.md for people who gets to your library without having enough experience of the model.

G.

[giacecco]

It looks like I may have solved with something that looks like below:

var outStream = require('fs').createWriteStream('foo.txt', { 'flags': 'w', 'encoding': 'utf-8' }),
    inStream = require('event-stream').through(function write(data) {
        this.emit('data', data);
    },
    function end () { 
        this.emit('end');
    });
inStream.pipe(outStream);
var emitter = new Emitter(function (data) {
    inStream.write(data);
});

Apparently there is no need for using pause, actually doing that causes a Nodejs warning:

.(node) warning: possible EventEmitter memory leak detected. 11 listeners added. Use emitter.setMaxListeners() to increase limit.

It is clear I am still missing the point of how event-stream works, this feels too much like magic :-)

G.

[timoxley]

Where is this data coming from? What is Emitter?

You can just write directly to your writable stream:

var outStream = require('fs').createWriteStream('foo.txt')
var emitter = new Emitter(function (data) {
    outStream.write(data);
});

[timoxley]

@giacecco if you want to master this stuff, you should start by doing stream-adventure: http://nodeschool.io/#stream-adventure