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Make sure you have the right versions

Goal:

Everybody should be running a version of node that has the necessary capabilities for the exercises

Process

People should have ideally a node 0.10.x version and npm 1.2.x version. We can probably live with node 0.8.2x and npm 1.2.x.

Cocytus:src jonathan$ node --version
v0.10.12
Cocytus:src jonathan$ npm --version
1.2.32
Cocytus:src jonathan$

Anybody who does not have a 0.10.x or 0.8.20-something node version should head to the separate table we'll try to have for getting people properly installed.

Get started

Goal:

Use decent/good node programming hygiene by using npm init to get coding started.

Process

Have people create a new directory somewhere to work in, then do a npm init:

Cocytus:src jonathan$ mkdir nodedc_meetup
Cocytus:src jonathan$ cd nodedc_meetup/
Cocytus:nodedc_meetup jonathan$ npm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sane defaults.

See `npm help json` for definitive documentation on these fields
and exactly what they do.

Use `npm install <pkg> --save` afterwards to install a package and
save it as a dependency in the package.json file.

Press ^C at any time to quit.
name: (nodedc_meetup)
version: (0.0.0)
description: _ENTER_A_DESCRIPTION_
entry point: (index.js) app.js
test command:
git repository:
keywords:
author: _INSERT_YOUR_NAME_HERE_
license: (BSD)
About to write to /Users/Jonathan/Files/src/nodedc_meetup/package.json:

{
  "name": "nodedc_meetup",
  "version": "0.0.0",
  "description": "_ENTER_A_DESCRIPTION_",
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "_INSERT_YOUR_NAME_HERE_",
  "license": "BSD"
}


Is this ok? (yes)
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No readme data.
Cocytus:nodedc_meetup jonathan$

We'll worry about the test and repository commands later, if at all: getting to either of those may be outside the scope of the meeting. The users also shouldn't worry about the 2 npm warnings at the end that resulted. But let's fix that No readme data warning now:

Cocytus:nodedc_meetup jonathan$ cat > README.md
_TYPE_OUT_A_USEFUL_DESCRIPTION_HERE?_
Cocytus:nodedc_meetup jonathan$

Write "Hello world" app

Goal

Have them write any simple working node script

Process

Have them edit hello.js to contain nothing but console.log('Hello, world');, save it, and then run it:

Cocytus:nodedc_meetup jonathan$ node hello.js
Hello, world!
Cocytus:nodedc_meetup jonathan$

Point out module use

Goal

Introduce concept of node modules, and show how even the most basic scripts usually use them

Process

There was a console.log in the previous example, that might be a good starting point to show that a module has already been used.

Explain modules as the base of how node code organization is done. We'll cover what one looks like in the next step.

Let's let them pass who they want to say hello to in on the command line, and have the answer include the hostname of the machine it came from. Here's hello2.js:

var os = require('os');

function WriteHello(predicate) {
  console.log('Hello, ' + predicate + ' from the machine ' + os.hostname() + '!');
}

WriteHello(process.argv[2]);

Let's point out that console and process are node system modules. They are provided by node and are always available. Then point out that os is also a module provided by node but not automatically loaded up through the `var os = require('os'); line

Make "Hello world" be a website

Goal

Serve out hello world over the web

Process

Have people create a simple, non-frameworked http website using just the node http module. A script something like this:

// Load the http module to create an http server.
var http = require('http');

// Configure our HTTP server to respond with Hello World to all requests.
var server = http.createServer(function (request, response) {
  response.writeHead(200, {"Content-Type": "text/html"});
  response.end("<html><head></head><body><h1>Hello World</h1></body></html>\n");
  console.log('Response sent at ' + new Date());
});

// Listen on port 3000, IP defaults to 127.0.0.1
server.listen(3000);

// Put a friendly message on the terminal
console.log("Server running at http://127.0.0.1:3000/");

Then have them run it, load up the page in a browser, and then kill it:

Cocytus:nodedc_meetup jonathan$ node app.js
Server running at http://127.0.0.1:3000/
Response sent at Mon Jul 15 2013 13:12:09 GMT-0400 (EDT)
Response sent at Mon Jul 15 2013 13:12:09 GMT-0400 (EDT)
^CCocytus:nodedc_meetup jonathan$

They should have seen "Hello World" as an H1 in the browser. Then have them look at the console and note that they got 2 responses sent here. Since this was a browser (unless you had them use curl or wget), the second is for /favicon.ico. Just a nifty reminder to point out to them that the server sees everything and should respond to it.

Use a 3rd party module and start using a web framework

Goal(s)

  • Learn how to install 3rd party modules via npm
  • Start using a web framework to build our app

Process

Have the user install express globally

Cocytus:nodedc_meetup jonathan$ sudo npm install -g express
Password:
## TON OF OUTPUT DELETED
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
[email protected] /usr/local/lib/node_modules/express
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected] ([email protected])
├── [email protected] ([email protected])
└── [email protected] ([email protected], [email protected], [email protected], [email protected], [email protected])
Cocytus:nodedc_meetup jonathan$

Now create an application:

Cocytus:nodedc_meetup jonathan$ mkdir express_app
Cocytus:nodedc_meetup jonathan$ cd express_app
Cocytus:express_app jonathan$ express -e

   create : .
   create : ./package.json
   create : ./app.js
   create : ./public
   create : ./public/javascripts
   create : ./public/images
   create : ./public/stylesheets
   create : ./public/stylesheets/style.css
   create : ./routes
   create : ./routes/index.js
   create : ./routes/user.js
   create : ./views
   create : ./views/index.ejs

   install dependencies:
     $ cd . && npm install

   run the app:
     $ node app

Cocytus:express_app jonathan$ npm install
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No readme data.
npm http GET https://registry.npmjs.org/express/3.3.4
npm http GET https://registry.npmjs.org/ejs
[email protected] node_modules/ejs

[email protected] node_modules/express
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected] ([email protected])
├── [email protected] ([email protected])
└── [email protected] ([email protected], [email protected], [email protected], [email protected], [email protected])
Cocytus:express_app jonathan$ node app
Express server listening on port 3000
```

and now go to http://localhost:3000/ (or whatever server port 3000) and you should see:

    # Express #
    
    Welcome to Express

## Build a form to collect input ##

### Goal ###
Be able to accept input and do something with it

### Process ###
Create a script that shows a form, takes in the POSTed input and does some transformation of the received data that then gets sent back to the user

## Take collected input and get a stock quote ##

### Goal ###
Using form-provided data, call a webservice to get JSON-encoded stock quote data and present the quote back to the user

### Process ###

Have them use node's ability to do client http requests to call the server we've built for the exercise with the user-supplied data, get the response, and send it back to the user

Google finance will return stock quote data.  Here's a sample URL for Microsoft: http://finance.google.com/finance/info?client=ig&q=MSFT

## Make WriteHello its own module ##

### Goal ###

Get everybody used to the idea of writing their own modules, and stress that modules are one of the things that make node really work by having lots of elementary building blocks put together.

### Process ###

Let's move the WriteHello method to its own module.  Have everybody make a lib subdirectory (`mkdir lib`) and make a hello module with one method in it, hello:
```
Cocytus:nodedc_meetup jonathan$ cat lib/hello.js
var os = require('os');

module.exports = {
  hello: function WriteHello(predicate) {
    console.log('Hello, ' + predicate + ' from the machine ' + os.hostname() + '!');
  }
}
```

And now have them update their hello script to use it:
```
Cocytus:nodedc_meetup jonathan$ cat hello3.js
var hello = require('./lib/hello');

hello.hello(process.argv[2]);
```
And show the output that results:
```
Cocytus:nodedc_meetup jonathan$ node hello3.js World
Hello, World from the machine Cocytus.local!
```