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author | David Heinemeier Hansson <david@loudthinking.com> | 2004-11-24 01:04:44 +0000 |
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committer | David Heinemeier Hansson <david@loudthinking.com> | 2004-11-24 01:04:44 +0000 |
commit | db045dbbf60b53dbe013ef25554fd013baf88134 (patch) | |
tree | 257830e3c76458c8ff3d1329de83f32b23926028 /activerecord/lib/active_record/validations.rb | |
download | rails-db045dbbf60b53dbe013ef25554fd013baf88134.tar.gz rails-db045dbbf60b53dbe013ef25554fd013baf88134.tar.bz2 rails-db045dbbf60b53dbe013ef25554fd013baf88134.zip |
Initial
git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
Diffstat (limited to 'activerecord/lib/active_record/validations.rb')
-rwxr-xr-x | activerecord/lib/active_record/validations.rb | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb new file mode 100755 index 0000000000..07bc7b99b5 --- /dev/null +++ b/activerecord/lib/active_record/validations.rb @@ -0,0 +1,205 @@ +module ActiveRecord + # Active Records implement validation by overwriting Base#validate (or the variations, +validate_on_create+ and + # +validate_on_update+). Each of these methods can inspect the state of the object, which usually means ensuring + # that a number of attributes have a certain value (such as not empty, within a given range, matching a certain regular expression). + # + # Example: + # + # class Person < ActiveRecord::Base + # protected + # def validate + # errors.add_on_empty %w( first_name last_name ) + # errors.add("phone_number", "has invalid format") unless phone_number =~ /[0-9]*/ + # end + # + # def validate_on_create # is only run the first time a new object is saved + # unless valid_discount?(membership_discount) + # errors.add("membership_discount", "has expired") + # end + # end + # + # def validate_on_update + # errors.add_to_base("No changes have occured") if unchanged_attributes? + # end + # end + # + # person = Person.new("first_name" => "David", "phone_number" => "what?") + # person.save # => false (and doesn't do the save) + # person.errors.empty? # => false + # person.count # => 2 + # person.errors.on "last_name" # => "can't be empty" + # person.errors.on "phone_number" # => "has invalid format" + # person.each_full { |msg| puts msg } # => "Last name can't be empty\n" + + # "Phone number has invalid format" + # + # person.attributes = { "last_name" => "Heinemeier", "phone_number" => "555-555" } + # person.save # => true (and person is now saved in the database) + # + # An +Errors+ object is automatically created for every Active Record. + module Validations + def self.append_features(base) # :nodoc: + super + + base.class_eval do + alias_method :save_without_validation, :save + alias_method :save, :save_with_validation + + alias_method :update_attribute_without_validation_skipping, :update_attribute + alias_method :update_attribute, :update_attribute_with_validation_skipping + end + end + + # The validation process on save can be skipped by passing false. The regular Base#save method is + # replaced with this when the validations module is mixed in, which it is by default. + def save_with_validation(perform_validation = true) + if perform_validation && valid? || !perform_validation then save_without_validation else false end + end + + # Updates a single attribute and saves the record without going through the normal validation procedure. + # This is especially useful for boolean flags on existing records. The regular +update_attribute+ method + # in Base is replaced with this when the validations module is mixed in, which it is by default. + def update_attribute_with_validation_skipping(name, value) + @attributes[name] = value + save(false) + end + + # Runs validate and validate_on_create or validate_on_update and returns true if no errors were added otherwise false. + def valid? + errors.clear + validate + if new_record? then validate_on_create else validate_on_update end + errors.empty? + end + + # Returns the Errors object that holds all information about attribute error messages. + def errors + @errors = Errors.new(self) if @errors.nil? + @errors + end + + protected + # Overwrite this method for validation checks on all saves and use Errors.add(field, msg) for invalid attributes. + def validate #:doc: + end + + # Overwrite this method for validation checks used only on creation. + def validate_on_create #:doc: + end + + # Overwrite this method for validation checks used only on updates. + def validate_on_update # :doc: + end + end + + # Active Record validation is reported to and from this object, which is used by Base#save to + # determine whether the object in a valid state to be saved. See usage example in Validations. + class Errors + def initialize(base) # :nodoc: + @base, @errors = base, {} + end + + # Adds an error to the base object instead of any particular attribute. This is used + # to report errors that doesn't tie to any specific attribute, but rather to the object + # as a whole. These error messages doesn't get prepended with any field name when iterating + # with each_full, so they should be complete sentences. + def add_to_base(msg) + add(:base, msg) + end + + # Adds an error message (+msg+) to the +attribute+, which will be returned on a call to <tt>on(attribute)</tt> + # for the same attribute and ensure that this error object returns false when asked if +empty?+. More than one + # error can be added to the same +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>. + # If no +msg+ is supplied, "invalid" is assumed. + def add(attribute, msg = "invalid") + @errors[attribute] = [] if @errors[attribute].nil? + @errors[attribute] << msg + end + + # Will add an error message to each of the attributes in +attributes+ that is empty (defined by <tt>attribute_present?</tt>). + def add_on_empty(attributes, msg = "can't be empty") + [attributes].flatten.each { |attr| add(attr, msg) unless @base.attribute_present?(attr) } + end + + # Will add an error message to each of the attributes in +attributes+ that has a length outside of the passed boundary +range+. + # If the length is above the boundary, the too_long_msg message will be used. If below, the too_short_msg. + def add_on_boundary_breaking(attributes, range, too_long_msg = "is too long (max is %d characters)", too_short_msg = "is too short (min is %d characters)") + for attr in [attributes].flatten + add(attr, too_short_msg % range.begin) if @base.attribute_present?(attr) && @base.send(attr).length < range.begin + add(attr, too_long_msg % range.end) if @base.attribute_present?(attr) && @base.send(attr).length > range.end + end + end + + alias :add_on_boundry_breaking :add_on_boundary_breaking + + # Returns true if the specified +attribute+ has errors associated with it. + def invalid?(attribute) + !@errors[attribute].nil? + end + + # * Returns nil, if no errors are associated with the specified +attribute+. + # * Returns the error message, if one error is associated with the specified +attribute+. + # * Returns an array of error messages, if more than one error is associated with the specified +attribute+. + def on(attribute) + if @errors[attribute].nil? + nil + elsif @errors[attribute].length == 1 + @errors[attribute].first + else + @errors[attribute] + end + end + + alias :[] :on + + # Returns errors assigned to base object through add_to_base according to the normal rules of on(attribute). + def on_base + on(:base) + end + + # Yields each attribute and associated message per error added. + def each + @errors.each_key { |attr| @errors[attr].each { |msg| yield attr, msg } } + end + + # Yields each full error message added. So Person.errors.add("first_name", "can't be empty") will be returned + # through iteration as "First name can't be empty". + def each_full + full_messages.each { |msg| yield msg } + end + + # Returns all the full error messages in an array. + def full_messages + full_messages = [] + + @errors.each_key do |attr| + @errors[attr].each do |msg| + if attr == :base + full_messages << msg + else + full_messages << @base.class.human_attribute_name(attr) + " " + msg + end + end + end + + return full_messages + end + + # Returns true if no errors have been added. + def empty? + return @errors.empty? + end + + # Removes all the errors that have been added. + def clear + @errors = {} + end + + # Returns the total number of errors added. Two errors added to the same attribute will be counted as such + # with this as well. + def count + error_count = 0 + @errors.each_value { |attribute| error_count += attribute.length } + error_count + end + end +end |