Module: ActiveRecord::Validations
- Defined in:
- lib/active_record/validations.rb
Overview
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.
Class Method Summary collapse
-
.append_features(base) ⇒ Object
:nodoc:.
Instance Method Summary collapse
-
#errors ⇒ Object
Returns the Errors object that holds all information about attribute error messages.
-
#save_with_validation(perform_validation = true) ⇒ Object
The validation process on save can be skipped by passing false.
-
#update_attribute_with_validation_skipping(name, value) ⇒ Object
Updates a single attribute and saves the record without going through the normal validation procedure.
-
#valid? ⇒ Boolean
Runs validate and validate_on_create or validate_on_update and returns true if no errors were added otherwise false.
Class Method Details
.append_features(base) ⇒ Object
:nodoc:
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# File 'lib/active_record/validations.rb', line 40 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 |
Instance Method Details
#errors ⇒ Object
Returns the Errors object that holds all information about attribute error messages.
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# File 'lib/active_record/validations.rb', line 75 def errors @errors = Errors.new(self) if @errors.nil? @errors end |
#save_with_validation(perform_validation = true) ⇒ Object
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.
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# File 'lib/active_record/validations.rb', line 54 def save_with_validation(perform_validation = true) if perform_validation && valid? || !perform_validation then save_without_validation else false end end |
#update_attribute_with_validation_skipping(name, value) ⇒ Object
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.
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# File 'lib/active_record/validations.rb', line 61 def update_attribute_with_validation_skipping(name, value) @attributes[name] = value save(false) end |
#valid? ⇒ Boolean
Runs validate and validate_on_create or validate_on_update and returns true if no errors were added otherwise false.
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# File 'lib/active_record/validations.rb', line 67 def valid? errors.clear validate if new_record? then validate_on_create else validate_on_update end errors.empty? end |