week 1 of hackyale ruby on rails course

8/3/2019 Week 1 of HackYale Ruby on Rails course

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www.hackyale.com

# Ruby on rails

Tuesday, January 17, 12
http://www.hackyale.com/http://www.hackyale.com/http://www.hackyale.com/http://www.hackyale.com/


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History, IntroductionRAILS AND YOU

http://www.hackyale.com/http://www.hackyale.com/


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WHo are these guys?

BUT FIRST



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COURSE INSTRUCTORS

Bay Gross

Junior in Davenport

co-founder @ Amicus

HardlyWork.in, chickentenders, whatsherface...

Charlie Croom

Senior in Sillimanco-founder @ Amicus

Yale Bluebook, whatsherface...



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what?

NOW FORRAILS



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WHAT IS RAILS?

A web developmentframework for ruby

like jQuery is aframework for Javascript

like Django is framework for Python

remember, ruby isjust a programming language

Created by David Heinemeier Hansson

at 37Signals



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WHAT IS A FRAMEWORK?

A framework is a library of common functions

it saves you work, but creates overhead



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SO IF RAILS IS A FRAMEWORK...

it lets you buildfast...

but with a cost

bigger codebase

slower execution

specific: bad threading, etc.

Rails is a bunch of pre-defined functions, methods, andstructures, written in ruby, that collectively allows us to developweb applications in ruby faster.



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WHAT SPECIFICALLY DOES IT GIVE ME?

common security holes

sessions, cookies

convenient (RESTful) routing

ORM functionality

MVC functionality

streamlined Asset caching

and more...



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WHAT MAKES IT SPECIAL?

Convention over Configuration

Dont Repeat Yourself (DRY)

Fast, flexible, dare-I-say agile development

open-source

fantastic community

rubyonrails.org

RailsConf

Meetups, etc.



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Stacks on stacks on stacks

OUR WORKINGSTACK



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What even is a STACK?

HOLD UP



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A set of software subsystems orcomponents needed to deliver a fully

functional solution, e.g. a product orservice.

STACK

LAMP: Linux, apache, mysql, php

LEAP: Linux, Eucalyptus, Appscale, python

to name a few...



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OUR STACK

We teach on the edge:

most of this software is < 1 month old

Rails (pre-release)

RVM (fixed yesterday)

Ruby 1.9.3 ( 1.9.2 is OK too)

RubyGems 1.8.14+

GIT

Heroku



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from the bottom up

WALK THE STACK



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OPERATING SYSTEMS

OSX

Lion, or Snow Leapord

yes, this is important.

remember. Were working on the edge

Windows

lol

Linux

oh cool so your a haxor?



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RVM

Ruby Version Manager [ OSX only ]

manage multiple versions of Ruby

manage multiple gem sets and versions of gems

encapsulate your projects



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RUBY

Similar to perl

many implementations

we will use the standard

higher level than C

comes pre-installed on OSX, but we will use RVM

plugins come packaged as gems

we use RubyGems to manage these!



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RUBYGEMS

install gems

update gems

delete gems

...



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RAILS

we know what this is now.

its just another gem!



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WEBRICK / APACHE

Servers

use WEBrick locally

use APACHE for production

other common alternatives include nginx

hosts yourserver-side (ie: ruby) code

handles requests

returns generated client-side (ie: html/css/javascript) code



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GIT

version control

developed by Linus Torvalds and crew

for version control of Linux!

track changes

collaborate

deploy (this is new + exciting)



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HEROKU

Fast deployment

essentially a front-end for Amazon EC2

create & deploy live web applications

using GIT!

Great for testing, small applications, static sites

For real applications, we use EC2 itself

Essentially a cloud server with its own stack



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The language, the legend

RUBY



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CRASH COURSE

Everything is an object

Everything has methods

literally everything, even numbers

0.zero? #=> true

Emphasis on readability

block statements defined w/o brackets

simba.is_a_lion? #=> conditional methods named witha question mark, trailing parenthesis optional



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CONVENTIONS

ClassNames

method_names + variable_names

methods_asking_questions?

slightly_dangerous_methods!

@instance_variables

@@class_variables

$global_variables

VARIOUS_CONSTANTS



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FEATURES

Free format scripting language

you can start typing anywhere

no headers, no int main

comments with a #

one statement per line

or use semi colons

everything is true

exceptfalse and nil



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0 is true. ZERO, the number, is true.

This will haunt your code.

HOLD UP



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OUTPUT

puts()

parenthesis are always optional in ruby functions

puts Hello world

puts Hello + my_planet.to_s

puts Hello #{my_planet}



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TYPES

Strings, Modulos (Classes), Arrays, Numerics, Hashes...

Strongly cast

type coercion is easy

10.to_s #=> 10

5.to_i #=> 5

hello.to_sym #=> :hello



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SPECIAL TYPES

Symbols

theyre everywhere!

What are they?

have string and integer component...

easy to read, but fast during runtime

:my_symbol

Hashes

built in. So hey, thats cool



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HASHES

Keys and Value pairs can be any type!

my_hash = { 5 => 10, hello => 2, world => :stop_it,{:nested_hash => make it stop!} => :inception}

but generally keys should be symbols

{ :name => Raptor, :claws => true }



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ITERATION

For loops... dont really exist as expected.

Usually one iterates over an enumerable set

array.each { |element| puts element }

array.map { |el| el.capitalize }

closest thing to a for loop?

(0..10).each { |i| puts i }

note: last statement in iteration is implicit return



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ITERATION

#Canalsobedonewithblocks:

array.mapdo|item|

putsitem

end



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BANG BANG BABY

The Bang (!) character

Denotes a clobbering method

days.select{ |d| d[0] == T }

days.select!{ |d| d[0] == T }



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Practice Ruby by running irb in yourterminal

IRB = Interactive Ruby Shell

TO THE TERMINAL!



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Questions?

[email protected] [ OSX ]

[email protected] [windows]

THATS IT
mailto:[email protected]:[email protected]:[email protected]:[email protected]

week 1 of hackyale ruby on rails course

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