In Ruby -> Test::unit::TestCase is easy

require ‘test/unit’

the name of the class to be tested is Roman then the testing class will TestRoman < Test::Unit::TestCase

and a simple method

def test_simple

assert_equal (“expected_result”, call_to the method of class to be checked –>actual result)

end

for testing a particular method….

ruby test_roman.rb –name “name of the method”

location of the test file should

$:.unshift File.join(File.dirname(__FILE__),”..”,”lib”)

require….the file to be tested (since require will bring the location of the file in previous line)

Test suite…

require ‘test/unit’ followed by all the test file names…it is as simple

require ‘test_roman’

require ‘test_music’

Numeric

Integer Float

FixNum BigNum Rational ComplexNum

nan?

zero?/nonzero?

finite?/infinite?,integer?

ceil,floor,round,

divmod,quo,remainder

next,succ,step(10,2),times,chr,

ruby is make like utility.Make utility makes a install with all the options and config you want .Rake is similar to Make

within a rails application go to that directory ask the rake to tell about itself

rake -T

rake rails:freeze:gems

rake doc:rails : will install the rdoc for the rails –> the activerecord#find etc…in the html format in the doc folder

rdoc *.rb *.c -o I:\sites\music_library\doc would generate the ruby style documentation in html for all the .rb files and .c files and output to the -o directory mentioned.

gem install “rspec”

ruby script/plugin install svn://rubyforge.org/var/svn/rspec/tags/REL_1_0_8/rspec_on_rails

ruby script/generate rspec

rake spec

Math is a module which has a lot of useful Methods.

To convert from one class to another just call the class name followed by parameter.

Integer(field)

Float(field)

String(field)

All other method are applied on the object itself like 3.div 3 or 12.divmod 5 which divides and gives the balance. or you can remainder to get the remainder alone.

you can question the number just like normal language like

.zero? .nonzero? .infinity? .finite? .nan? .integer? .float? .ciel .floor .round .next .chr .log .sqrt .exp .length

To get constants since it is a Module Math::PI

Prime numbers : Prime.new : p.next,p.succ.

render(:controller=>’say’ ,:action=>’hello’)

render(:partial => ‘form’)

redirect(:controller=>’say’ :action=>’hello’)

link_to(‘mylink’,:controller= >’say’,:action=>’hello’,:id=>1)

params.inspect

logger.warn,logger.error,logger.info,logger.fatal

(ActionView only) debug(params)

( FormHelpers only)

<input type =’text’ name=album[title]/> can be written as

<%= form_tag(:action=>’create’) do %>

<%= text_field(:album, :title) %>

<%= datetime_select(:album, :release_date) %>

<%= submit_tag(“name of button”) %>

<%= end %>

form_tag

form

error_messages_for(:album) —> debug(album.errors)

validates_presence_of :artist

before_filter(controller) :method nly/:except =>[]

after_filter(controller) :method nly

Model inherits from ActiveRecord::Base which has methods like find,find_by_id,find_by_sql,save,update,destroy

Controller is inherited from ApplicationController

stylesheet_link_tag

layout(controller)

render(:layout=>false/’standard’) / render_without_layout

before_create(ActiveRecord::Base)

after_create(ActiveRecord::Base)

flash[:notice] = ’successful created’

Database table end with s…Albums,Artists,

But the model is singular and the controller is

Sql

1)find(:all, –> :first,:last,1….

(where clause) :conditions= >["release_date <= ?","YYYY-MM-DD HH:MM:SS"] –> sql inject attack…

rder=>’release_date ASC’

:limit => 10 , ffset => 5

{
:primary_key => “int(11) DEFAULT NULL auto_increment PRIMARY KEY”,
:string => { :name => “varchar”, :limit => 255 },
:text => { :name => “text” },
:integer => { :name => “int”, :limit => 11 },
:float => { :name => “float” },
:decimal => { :name => “decimal” },
:datetime => { :name => “datetime” },
:timestamp => { :name => “datetime” },
:time => { :name => “time” },
:date => { :name => “date” },
:binary => { :name => “blob” },
:boolean => { :name => “tinyint”, :limit => 1 }
}

2)create a new model and call .save(will return true / false)

3)destroy : instance of the model.destroy

4)update_attributes : instance of the model.update(params–>hash)

PARAMS

is a hash.so to get the params say params[:key] eg params[:id]

http://docs.rubygems.org/read/book/2

gem -v : would give the version

gem list –local : list of all gems in the system with thier version number.if there was 2 version then it would give them in descending order

gem outdated : would give list of gems which are outdate

gem update : would update all the gems.

gem update –include-dependencies –no-rdoc

gem cleanup : would clean the older version when there are 2 version available

gem uninstall y4mr : would uninstall that gem

gem install –remote y4mr : would install that gem from the remote repository…

gem install -v=2.0.2 rails would install a particular version of rails

gem dependency rails : would list all the dependencies for a gem

gem query -n ‘rai.*’ : (-n —> regular expression ) would query the gem which matches in thier name . you can make it remote by say –remote

gem unpack : would unpack all the gems to the rails/vendor/plugin

rails . : would get the new updated gems

$0 is the file which load any other ruby file which is contained in __FILE__….

* is called the splat operator in ruby .The first time you come across is for variable argument.that is exactly what you will be using it for.it should be used as the last argument.

name,*rest_of_address = address[]

would put the first argument to name and rest to the * argument…

THe other thing about it is it gives a copy of the variable not the reference….

what you can do with this on Struct and Hash is split it….using splat as an array and get it individual…

you can use even in the case statement..to check the equal to

and *array passed on to the other array will flatten it..

If you wanted just a storage variable in terms of big structure with no code on them .The best way is to call Struct.new followed by what ever structure fields you want on them.Once the structure is created you can create a new on it by just calling the name of the Structure .new and intialize all the fields in it.You can directly access all the fields directly on it…

to perform some operations on it….

class Symbol
def to_proc
Proc.new { |*args| args.shift.__send__(self, *args) }
end
end

PhoneNumber = Struct.new :area_code
*phone_numbers = PhoneNumber.new(904), PhoneNumber.new(646), PhoneNumber.new(616)
area_codes = phone_numbers.collect &:area_code #=> [904, 646, 616]

Time.now : will give the time now…

%a – The abbreviated weekday name (“Sun”)
%A – The full weekday name (“Sunday”)
%b – The abbreviated month name (“Jan”)
%B – The full month name (“January”)
%c – The preferred local date and time representation
%d – Day of the month (01..31)
%H – Hour of the day, 24-hour clock (00..23)
%I – Hour of the day, 12-hour clock (01..12)
%j – Day of the year (001..366)
%m – Month of the year (01..12)
%M – Minute of the hour (00..59)
%p – Meridian indicator (“AM” or “PM”)
%S – Second of the minute (00..60)
%U – Week number of the current year,
starting with the first Sunday as the first
day of the first week (00..53)
%W – Week number of the current year,
starting with the first Monday as the first
day of the first week (00..53)
%w – Day of the week (Sunday is 0, 0..6)
%x – Preferred representation for the date alone, no time
%X – Preferred representation for the time alone, no date
%y – Year without a century (00..99)
%Y – Year with century
%Z – Time zone name
%% – Literal “%” character

t = Time.now
t.strftime(“Printed on %m/%d/%Y”) #=> “Printed on 04/09/2003″
t.strftime(“at %I:%M%p”) #=> “at 08:56AM”

to create a new time stamp Time.mktime(yyyy,mm,dd,hh,mm,ss)

commonly used methods are Time.year,month,day,wday,yday,hour,min,sec,zone or the cannonical time.

Time.ctime,Time.utc(universal time,GMT),Time.dst?(daylight saving time),

You can use the normal compare eql?/<=>/ subtracting(gives in terms of seconds)/ you can add seconds .say if you want add 24 hours you say Time.now + 24 * 60 * 60

Date

Date.today: to get today’s date

Date.new(yyyy,mm,dd)

commonly used are to_s,succ,next,leap, to add and subtract just use + / – (it will done in terms of days). to add /subtract months use >> / <<.

downto/upto methods can be used for countdowns on the date object using another date object as parameter.. d1.upto(d2){ |d| block }

parsedate: require “parsedate.rb” p parsedate (“12/24/2008″)