バリデーション

バリデーションを定義する

app/modles/entry.rb
class Entry < ActiveRecord::Base
validates_presence_of :title
end

class Entry < ActiveRecord:Base
validates_presence_of :title, :content, :on => :create
end

バリデーション　パラメータ

:message 
:on
:if
:unless
:allow_nil

バリデーション　宣言

validates_presense_of |   can't be blank 
validates_length_of | 後述   
validates_numericality_of |   is not anumber
validates_format_of |    is invalid
validates_inclusion_of  |  is not included in the list
validates_exclusion_of |   is reserved
validates_confirmation_of |  doesn't match confimation
validates_uniqueness_of |   has already been taken
validates_acceptance_of |   must be accepted
validates_associated |   is invalid

app/models/user.rb
class User < ActiveRecord::Base
validates_confimation_of :password
<%= password_field "user", "password" %>
<%= password_confimationの入力項目も用意する %>
<%= password_field"user", "password_confimation" %>

...
end

validates_length_of

class Blog < ActiveRecord::Base
validates_length_of :title, :in => (2..30)
:too_short => "タイトルは2文字以上で入力してください。"
:too_long => "タイトルは30文字以下で入力してください。"
end

:minimum
:maximum
:is
:in/:within
:too_long
:too_short
:wrong_length
:message

validate_uniquness_of

class Entry < ActiveRecord::Base
validates_uniqueness_of :title, :scope => [:blog_id]
end

:scope
:case_sensitive