validate_block¶ ↑

• github.com/xunker/validate_block

This gem is NOT maintained. The funcationality has been replaced by ActiveRecord ‘with_option`: guides.rubyonrails.org/active_record_validations.html#grouping-conditional-validations. I’d like to think this gem had a little something to do with that being added to AR :)

This gem allows similar ActiveRecord validates_* commands to be grouped together in blocks and pruned of repeated parameters.

How often have you had a block of validation commands in an ActiveRecord object that are repeated, especially :id or :unless options? Does this look familiar?

validates_presence_of  :hair, :hair_color, :unless => :bald?
validates_length_of    :hair, :within => 3..15, :unless => :bald?
validates_inclusion_of :hair_color, :in => HAIR_COLORS, :unless => bald?

Instead, this gem will allow you to replace the above code with:

validate_block :unless => :bald? do
  presence_of  :hair, :hair_color
  length_of    :hair, :within => 3..15
  inclusion_of :hair_color, :in => HAIR_COLORS
end

..which is a great way to DRY your :hair, don’t you think?

Basically, this gem 1) removes the requirement to have ‘validates_’ on the front of the commands and 2) passes the options on the validate_block command to each validation command inside the block.

The syntax of the validation commands remains the same. Keeping the ‘validates_*’ prefix on the commands inside the block will work but it is not required.

require 'rubygems'
require 'activerecord'
require 'validate_block'

class SomeObject < ActiveRecord::Base

  validate_block :if => :some_method? do
    presence_of :some_field
    inclusion_of :some_other_field, :in => SOME_VALUES
  end

end

ActiveRecord >= 2.1.0

sudo gem install validate_block

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