Difference between revisions of "Ruby on Rails"

Latest revision as of 02:47, 12 July 2013

Ruby is a language, rails is a framework. Ruby is a object-oriented, general purpose language. I attended a Railsbridge session at newcontext on 13 May 2012. These are some notes from that lesson.

• http://curriculum.railsbridge.org/curriculum
• my first ruby app

rails philosophy

• opinionated
• convention over configuration
• don't repeat yourself
• test driven
• minimal code - maximal effect

the tools

• rails
• rake - like make for ruby (an easy way to run tasks)
• git - source code control
• database - SQlite
• heroku - free rails hosting

the command line

• Current directory: . ("dot")
• Parent directory: .. ("dot dot")
• Home directory: ~ ("tilde")

• ls - list
• cd - go to directory (use cd ~ to go backwards)
• pwd - "print working directory"
• echo - repeats it (used to echo out $PATH)
• touch - creates a file
• cat - tells info
• mv - move
• cp - copy
• rm - remove (DELETE FOREVER)
• man <command> - tells you more (press q to get out) (man - manual)
• mkdir - make directory
• rmdir - remove directory
• mdfind - find file (find via spotlight)

Example:

• to rename a file frm file1 to file2 and move file to a different dir: mv file1 dir1/file2

• Command-K to clear screen

• cat <filename> - prints the file
• ruby <filename> - runs the file

• git status - check git (versioning) status
• git add . - prepare to commit everything all files
• git add <filename> - prepare to commit specific file
• git commit -m - commit that file
• git help <function name>

irb test example

1.9.3p194 :024 > def test (name="debbie", country="singapore")
1.9.3p194 :025?>   puts "My name is #{name}"
1.9.3p194 :026?>   puts "My country is #{country}"
1.9.3p194 :027?>   end
 => nil 
1.9.3p194 :028 > test
My name is debbie
My country is singapore
 => nil 
1.9.3p194 :029 > 

standalone file test - newfile.rb

use chomp to delete the extra line break. ! means WATCH OUT

# Clear screen
puts "\e[H\e[2J"

# Ask
puts "What is your name?"
$name = STDIN.gets
puts "\e[H\e[2J"
$name.chomp!
# $name = $name.reverse
puts "Hello " + $name
puts "Where do you live?"

$place = STDIN.gets
puts "\e[H\e[2J"
puts "Hello "+$name+" who lives in " + $place

pretty links

the pretty permalinks are referred to as "slug" here, there are slugger and slugify plugins but those are more complicated. to_param will do to make a pretty link. this code goes into the model.

def to_param  # overridden
	 "#{id}-#{title.parameterize}"
end

Naming Conventions

• methods and variables are in snake_case
• classes and modules are in CamelCase
• constants are in ALL_CAPS

Variables

• var # local variable (or method call)
• @var # instance variable
• @@var # class variable
• $var # global variable
• VAR # constant

CRUD

• Create new records in the database
• Read or show the records in the database
• Update existing records
• Destroy or delete records

See Also

• Ruby Toolbox
• devchix
• http://workshops.railsbridge.org/
• http://curriculum.railsbridge.org/workshop
• github
• slidedown - also see slidedown on github
• http://mxcl.github.com/homebrew/