learn-node

Solutions for exercises from selected workshops in Node. Self-paced, focus on clarity over efficiency.

Targeted a select few based on what I wanted to learn. May do more workshops in the distant future.

• node: learnyounode
• promises: promise-it-wont-hurt
• functional: functional-javascript-workshop

Note: For promises, use Node's Argon (LTS v4.9.1). I recommend nvm use v4.9.1.

What is Node?

A simple I/O platform to write JavaScript. Many things constitute as I/O, such as:

• Reading/writing files
• Pushing notifications
• Managing an API
• Managing a Database
• Caching
• Resource buckets

It is async, or non-blocking. It supports callbacks, events, streams, and modules.

Callbacks are the core essence that powers asynchronicity. Typically, async/await is used in tandem.

Events act as pub/sub, and we connect callbacks to each. Events are many-to-many, so the same event can trigger multiple callbacks, and there can exist multiple events.

// For example,
client.on('eventOne', callbackOne);
client.on('eventOne', callbackTwo);
client.on('eventTwo', callbackThree);

Streams work exactly like in UNIX, using backpressure to throttle flow. In ohter words, it minimizes buffering data to chunks. It's also a countermeasure to callback hell.

const http = require('http');
const fs = require('fs');

// Without streams,
const server = http.createServer((req, res) => {
    fs.readFile(__dirname + '/data.txt', (err, data) => {
        res.end(data);
    });
});

// With streams,
const server = http.createServer((req, res) => {
    const stream = fs.createReadStream(__dirname + '/data.txt');
    stream.pipe(res);
});

server.listen(8000);

Modules have a similar philosophy to streams. They allow for separation of concerns with code. With Node, it opts for local package management similar to Python's virtual environment by default.

Sources

Resources for learning + building with Node.

• art-of-node for an introduction to Node.
• NodeSchool for a list of active workshops.