diff options
Diffstat (limited to 'railties/guides/source/active_record_validations_callbacks.textile')
| -rw-r--r-- | railties/guides/source/active_record_validations_callbacks.textile | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/railties/guides/source/active_record_validations_callbacks.textile b/railties/guides/source/active_record_validations_callbacks.textile index 5dc6ef3774..e5349d546c 100644 --- a/railties/guides/source/active_record_validations_callbacks.textile +++ b/railties/guides/source/active_record_validations_callbacks.textile @@ -461,11 +461,11 @@ The block receives the model, the attribute's name and the attribute's value. Yo h3. Common Validation Options -There are some common options that all the validation helpers can use. Here they are, except for the +:if+ and +:unless+ options, which are discussed later in "Conditional Validation":#conditional-validation. +These are common validation options: h4. +:allow_nil+ -The +:allow_nil+ option skips the validation when the value being validated is +nil+. Using +:allow_nil+ with +validates_presence_of+ allows for +nil+, but any other +blank?+ value will still be rejected. +The +:allow_nil+ option skips the validation when the value being validated is +nil+. <ruby> class Coffee < ActiveRecord::Base @@ -474,6 +474,8 @@ class Coffee < ActiveRecord::Base end </ruby> +TIP: +:allow_nil+ is ignored by the presence validator. + h4. +:allow_blank+ The +:allow_blank+ option is similar to the +:allow_nil+ option. This option will let validation pass if the attribute's value is +blank?+, like +nil+ or an empty string for example. @@ -487,6 +489,8 @@ Topic.create("title" => "").valid? # => true Topic.create("title" => nil).valid? # => true </ruby> +TIP: +:allow_blank+ is ignored by the presence validator. + h4. +:message+ As you've already seen, the +:message+ option lets you specify the message that will be added to the +errors+ collection when validation fails. When this option is not used, Active Record will use the respective default error message for each validation helper. @@ -738,7 +742,20 @@ person.errors.size # => 0 h3. Displaying Validation Errors in the View -Rails provides built-in helpers to display the error messages of your models in your view templates. +Rails maintains an official plugin that provides helpers to display the error messages of your models in your view templates. You can install it as a plugin or as a Gem. + +h4. Installing as a plugin +<shell> +$ rails plugin install git://github.com/joelmoss/dynamic_form.git +</shell> + +h4 Installing as a Gem +Add this line on your Gemfile: +<ruby> +gem "dynamic_form" +</ruby> + +Now you will have access to these two methods in your view templates: h4. +error_messages+ and +error_messages_for+ |