Class: ActiveRecord::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/activerecord/utils/alias.rb,
lib/activerecord/utils/comp3.rb,
lib/activerecord/utils/random.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.alias_attr(new, old) ⇒ Object 



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# File 'lib/activerecord/utils/alias.rb', line 35

def self.alias_attr( new, old )
  alias_attr_reader( new, old )
  alias_attr_writer( new, old )
end

.alias_attr_reader(new, old) ⇒ Object

todo: add opts={} e.g. lets us add, for example, depreciated: true ??

- will issue a warning



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# File 'lib/activerecord/utils/alias.rb', line 20

def self.alias_attr_reader( new, old )
  define_method( new ) do
    send( old )
    ### use read_attribute( old ) instead? why? why not??

    #  see http://www.davidverhasselt.com/2011/06/28/5-ways-to-set-attributes-in-activerecord/

  end
  ## todo: check for boolean values - add new? version too ??

end

.alias_attr_writer(new, old) ⇒ Object 



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# File 'lib/activerecord/utils/alias.rb', line 29

def self.alias_attr_writer( new, old )
  define_method( "#{new}=" ) do |value|
    send( "#{old}=", value )
  end
end

.attr_reader_w_fallbacks(*keys) ⇒ Object 



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# File 'lib/activerecord/utils/alias.rb', line 54

def self.attr_reader_w_fallbacks( *keys )
  define_method( keys[0] ) do
    read_attribute_w_fallbacks( keys )
  end
end

.find_by(hash) ⇒ Object

lets us use ActiveRecord 4-style find_by and find_by! in ActiveRecord 3.x



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# File 'lib/activerecord/utils/comp3.rb', line 12

def self.find_by( hash )
  self.where( hash ).first
end

.find_by!(hash) ⇒ Object 



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# File 'lib/activerecord/utils/comp3.rb', line 16

def self.find_by!( hash )
  self.where( hash ).first!     ## or use: first or raise RecordNotFound  directly??

end

.rnd ⇒ Object

random

e.g. use like:

 beer_of_the_week = Beer.rnd



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# File 'lib/activerecord/utils/random.rb', line 14

def self.rnd
  ## works w/ sqlite3 and postgresql

  ##  - check if it works w/ mysql/mariadb too ? suppots offset and limit in SQL?


  ## todo: use ::rand  -- and lets add an self.rand alias too ??

  ##  check if ::rand call works

  rnd_offset = rand( self.count ) ## NB: call "global" std lib rand


  self.offset( rnd_offset ).limit( 1 ).first
end

Instance Method Details

#read_attribute_w_fallbacks(*keys) ⇒ Object 



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# File 'lib/activerecord/utils/alias.rb', line 60

def read_attribute_w_fallbacks( *keys )
  ### todo: use a different name e.g.:

  ## read_attribute_cascade ?? - does anything like this exists already?

  ## why? why not?

  value = nil
  keys.each do |key|
    value = read_attribute( key )
    break unless value.nil?  # if value.nil? == false

  end
  value # fallthrough -- return latest value (will be nil)

end