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| -rw-r--r-- | railties/guides/source/activerecord_validations_callbacks.textile | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/railties/guides/source/activerecord_validations_callbacks.textile b/railties/guides/source/activerecord_validations_callbacks.textile index 03d521ea1f..9d0ee29ff2 100644 --- a/railties/guides/source/activerecord_validations_callbacks.textile +++ b/railties/guides/source/activerecord_validations_callbacks.textile @@ -403,6 +403,47 @@ WARNING. Note that some databases are configured to perform case-insensitive sea The default error message for +validates_uniqueness_of+ is "_has already been taken_". +h4. +validates_with+ + +This helper passes the record to a separate class for validation. + +<ruby> +class Person < ActiveRecord::Base + validates_with GoodnessValidator +end + +class GoodnessValidator < ActiveRecord::Validator + def validate + if record.first_name == "Evil" + record.errors[:base] << "This person is evil" + end + end +end +</ruby> + +The +validates_with+ helper takes a class, or a list of classes to use for validation. There is no default error message for +validates_with+. You must manually add errors to the record's errors collection in the validator class. + +The validator class has two attributes by default: + +* +record+ - the record to be validated +* +options+ - the extra options that were passed to +validates_with+ + +Like all other validations, +validates_with+ takes the +:if+, +:unless+ and +:on+ options. If you pass any other options, it will send those options to the validator class as +options+: + +<ruby> +class Person < ActiveRecord::Base + validates_with GoodnessValidator, :fields => [:first_name, :last_name] +end + +class GoodnessValidator < ActiveRecord::Validator + def validate + if options[:fields].any?{|field| record.send(field) == "Evil" } + record.errors[:base] << "This person is evil" + end + end +end +</ruby> + h4. +validates_each+ This helper validates attributes against a block. It doesn't have a predefined validation function. You should create one using a block, and every attribute passed to +validates_each+ will be tested against it. In the following example, we don't want names and surnames to begin with lower case. |