devongovett

# Syntax for private methods in CoffeeScript

class Test
    publicMethod: ->
        alert @foo
		
    private
        foo: "hello world!"
	privateMethod ->
	    "private"

devongovett

#this is the coffeescript with method overloading

class User
	find: (id) ->
		console.log "find by id"
	
	find: (first, last) ->
		console.log "find by first and last name"
		
class NewUser extends User

devongovett

// 1: how could you rewrite the following to make it shorter?
foo ? bar.doSomething(el) : bar.doSomethingElse(el);

// 2: what is the faulty logic in the following code?

//you are creating a local version of foo instead of overwriting
//the global version.  Thus, foo will always be equal to world.
//The problem is fixed below.
var foo = 'hello';

devongovett

This CoffeeScript:

15 + if somevar then "%"

used to compile to this JavaScript:

15 + (somevar ? "%" : null)

which returned 15 if somevar was false.
Now it compiles to:

devongovett

# fill path to ctx
Path.fill(ctx, "M250 150 L150 350 L350 350 Z")

# stroke
Path.stroke(ctx, "M250 150 L150 350 L350 350 Z")

# clip
Path.render(ctx, "M250 150 L150 350 L350 350 Z")
ctx.clip()

devongovett

var arr = [],
    obj = {'abcdef' : 1, 'qqq' : 13, '19' : [1, 2, 3, 4]};

for(var i = 0; i < 5000; i++)
    arr.push(obj);

// jsondb(arr) looks something like this:
// ["abcdef", "qqq", "19", [1, 13, [1, 2, 3, 4]], [1, 13, [1, 2, 3, 4]]...]

> JSON.stringify(arr).length //original

devongovett

###
# JSONDB - a compressed JSON format
# By Devon Govett
# Originally proposed by Peter Michaux - http://michaux.ca/articles/json-db-a-compressed-json-format
#
# jsondb.pack converts an array of objects with the same keys (i.e. from a database) 
# and flattens them into a single array, which is much smaller than the pure json 
# representation where the keys are repeated for each item in the array.  
# Combine with JSON.stringify to send compressed JSON data over the network.
#

devongovett

PDFDocument = require 'pdfkit'
doc = new PDFDocument

# Embed a font, set the font size, and render some text
doc.font('fonts/PalatinoBold.ttf')
   .fontSize(25)
   .text('Some text with an embedded font!', 100, 100)

# Add another page
doc.addPage()

devongovett

doc.addPage
  size: 'legal'
  layout: 'landscape'

devongovett

lorem = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed pulvinar diam eu ' +
        'dolor bibendum et varius diam laoreet. Morbi eget rutrum enim. Sed enim ipsum, ' +
        'posuere nec hendrerit non, commodo quis tortor. Fusce id nisl augue. Fusce at ' +
        'lectus ut libero vehicula imperdiet.'

doc.text 'This text is left aligned. ' + lorem, 100, 100, 
    width: 410
    align: 'left'
    
doc.moveDown()