From 638333b7a17234ed65b2e8b0bee3d9b533446803 Mon Sep 17 00:00:00 2001 From: Pratik Naik Date: Thu, 19 Mar 2009 23:36:08 +0000 Subject: Move uniqueness and association validations to Active Record --- .../lib/active_model/validations/associated.rb | 47 ------ .../lib/active_model/validations/uniqueness.rb | 159 --------------------- 2 files changed, 206 deletions(-) delete mode 100644 activemodel/lib/active_model/validations/associated.rb delete mode 100644 activemodel/lib/active_model/validations/uniqueness.rb (limited to 'activemodel/lib/active_model') diff --git a/activemodel/lib/active_model/validations/associated.rb b/activemodel/lib/active_model/validations/associated.rb deleted file mode 100644 index ba4af5d66d..0000000000 --- a/activemodel/lib/active_model/validations/associated.rb +++ /dev/null @@ -1,47 +0,0 @@ -module ActiveModel - module Validations - module ClassMethods - # Validates whether the associated object or objects are all valid themselves. Works with any kind of association. - # - # class Book < ActiveRecord::Base - # has_many :pages - # belongs_to :library - # - # validates_associated :pages, :library - # end - # - # Warning: If, after the above definition, you then wrote: - # - # class Page < ActiveRecord::Base - # belongs_to :book - # - # validates_associated :book - # end - # - # this would specify a circular dependency and cause infinite recursion. - # - # NOTE: This validation will not fail if the association hasn't been assigned. If you want to ensure that the association - # is both present and guaranteed to be valid, you also need to use +validates_presence_of+. - # - # Configuration options: - # * :message - A custom error message (default is: "is invalid") - # * :on - Specifies when this validation is active (default is :save, other options :create, :update). - # * :if - Specifies a method, proc or string to call to determine if the validation should - # occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The - # method, proc or string should return or evaluate to a true or false value. - # * :unless - Specifies a method, proc or string to call to determine if the validation should - # not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The - # method, proc or string should return or evaluate to a true or false value. - def validates_associated(*attr_names) - configuration = { :on => :save } - configuration.update(attr_names.extract_options!) - - validates_each(attr_names, configuration) do |record, attr_name, value| - unless (value.is_a?(Array) ? value : [value]).collect { |r| r.nil? || r.valid? }.all? - record.errors.add(attr_name, :invalid, :default => configuration[:message], :value => value) - end - end - end - end - end -end \ No newline at end of file diff --git a/activemodel/lib/active_model/validations/uniqueness.rb b/activemodel/lib/active_model/validations/uniqueness.rb deleted file mode 100644 index 37beac863f..0000000000 --- a/activemodel/lib/active_model/validations/uniqueness.rb +++ /dev/null @@ -1,159 +0,0 @@ -module ActiveModel - module Validations - module ClassMethods - # Validates whether the value of the specified attributes are unique across the system. Useful for making sure that only one user - # can be named "davidhh". - # - # class Person < ActiveRecord::Base - # validates_uniqueness_of :user_name, :scope => :account_id - # end - # - # It can also validate whether the value of the specified attributes are unique based on multiple scope parameters. For example, - # making sure that a teacher can only be on the schedule once per semester for a particular class. - # - # class TeacherSchedule < ActiveRecord::Base - # validates_uniqueness_of :teacher_id, :scope => [:semester_id, :class_id] - # end - # - # When the record is created, a check is performed to make sure that no record exists in the database with the given value for the specified - # attribute (that maps to a column). When the record is updated, the same check is made but disregarding the record itself. - # - # Configuration options: - # * :message - Specifies a custom error message (default is: "has already been taken"). - # * :scope - One or more columns by which to limit the scope of the uniqueness constraint. - # * :case_sensitive - Looks for an exact match. Ignored by non-text columns (+true+ by default). - # * :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+). - # * :allow_blank - If set to true, skips this validation if the attribute is blank (default is +false+). - # * :if - Specifies a method, proc or string to call to determine if the validation should - # occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The - # method, proc or string should return or evaluate to a true or false value. - # * :unless - Specifies a method, proc or string to call to determine if the validation should - # not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The - # method, proc or string should return or evaluate to a true or false value. - # - # === Concurrency and integrity - # - # Using this validation method in conjunction with ActiveRecord::Base#save - # does not guarantee the absence of duplicate record insertions, because - # uniqueness checks on the application level are inherently prone to race - # conditions. For example, suppose that two users try to post a Comment at - # the same time, and a Comment's title must be unique. At the database-level, - # the actions performed by these users could be interleaved in the following manner: - # - # User 1 | User 2 - # ------------------------------------+-------------------------------------- - # # User 1 checks whether there's | - # # already a comment with the title | - # # 'My Post'. This is not the case. | - # SELECT * FROM comments | - # WHERE title = 'My Post' | - # | - # | # User 2 does the same thing and also - # | # infers that his title is unique. - # | SELECT * FROM comments - # | WHERE title = 'My Post' - # | - # # User 1 inserts his comment. | - # INSERT INTO comments | - # (title, content) VALUES | - # ('My Post', 'hi!') | - # | - # | # User 2 does the same thing. - # | INSERT INTO comments - # | (title, content) VALUES - # | ('My Post', 'hello!') - # | - # | # ^^^^^^ - # | # Boom! We now have a duplicate - # | # title! - # - # This could even happen if you use transactions with the 'serializable' - # isolation level. There are several ways to get around this problem: - # - By locking the database table before validating, and unlocking it after - # saving. However, table locking is very expensive, and thus not - # recommended. - # - By locking a lock file before validating, and unlocking it after saving. - # This does not work if you've scaled your Rails application across - # multiple web servers (because they cannot share lock files, or cannot - # do that efficiently), and thus not recommended. - # - Creating a unique index on the field, by using - # ActiveRecord::ConnectionAdapters::SchemaStatements#add_index. In the - # rare case that a race condition occurs, the database will guarantee - # the field's uniqueness. - # - # When the database catches such a duplicate insertion, - # ActiveRecord::Base#save will raise an ActiveRecord::StatementInvalid - # exception. You can either choose to let this error propagate (which - # will result in the default Rails exception page being shown), or you - # can catch it and restart the transaction (e.g. by telling the user - # that the title already exists, and asking him to re-enter the title). - # This technique is also known as optimistic concurrency control: - # http://en.wikipedia.org/wiki/Optimistic_concurrency_control - # - # Active Record currently provides no way to distinguish unique - # index constraint errors from other types of database errors, so you - # will have to parse the (database-specific) exception message to detect - # such a case. - def validates_uniqueness_of(*attr_names) - configuration = { :case_sensitive => true } - configuration.update(attr_names.extract_options!) - - validates_each(attr_names,configuration) do |record, attr_name, value| - # The check for an existing value should be run from a class that - # isn't abstract. This means working down from the current class - # (self), to the first non-abstract class. Since classes don't know - # their subclasses, we have to build the hierarchy between self and - # the record's class. - class_hierarchy = [record.class] - while class_hierarchy.first != self - class_hierarchy.insert(0, class_hierarchy.first.superclass) - end - - # Now we can work our way down the tree to the first non-abstract - # class (which has a database table to query from). - finder_class = class_hierarchy.detect { |klass| !klass.abstract_class? } - - column = finder_class.columns_hash[attr_name.to_s] - - if value.nil? - comparison_operator = "IS ?" - elsif column.text? - comparison_operator = "#{connection.case_sensitive_equality_operator} ?" - value = column.limit ? value.to_s[0, column.limit] : value.to_s - else - comparison_operator = "= ?" - end - - sql_attribute = "#{record.class.quoted_table_name}.#{connection.quote_column_name(attr_name)}" - - if value.nil? || (configuration[:case_sensitive] || !column.text?) - condition_sql = "#{sql_attribute} #{comparison_operator}" - condition_params = [value] - else - condition_sql = "LOWER(#{sql_attribute}) #{comparison_operator}" - condition_params = [value.mb_chars.downcase] - end - - if scope = configuration[:scope] - Array(scope).map do |scope_item| - scope_value = record.send(scope_item) - condition_sql << " AND " << attribute_condition("#{record.class.quoted_table_name}.#{scope_item}", scope_value) - condition_params << scope_value - end - end - - unless record.new_record? - condition_sql << " AND #{record.class.quoted_table_name}.#{record.class.primary_key} <> ?" - condition_params << record.send(:id) - end - - finder_class.with_exclusive_scope do - if finder_class.exists?([condition_sql, *condition_params]) - record.errors.add(attr_name, :taken, :default => configuration[:message], :value => value) - end - end - end - end - end - end -end -- cgit v1.2.3