diff options
Diffstat (limited to 'railties/guides/source/active_record_validations_callbacks.textile')
-rw-r--r-- | railties/guides/source/active_record_validations_callbacks.textile | 51 |
1 files changed, 26 insertions, 25 deletions
diff --git a/railties/guides/source/active_record_validations_callbacks.textile b/railties/guides/source/active_record_validations_callbacks.textile index 665e7f9ccc..15d24f9ac1 100644 --- a/railties/guides/source/active_record_validations_callbacks.textile +++ b/railties/guides/source/active_record_validations_callbacks.textile @@ -614,7 +614,7 @@ As shown in the example, you can also combine standard validations with your own h4. Custom Methods -You can also create methods that verify the state of your models and add messages to the +errors+ collection when they are invalid. You must then register these methods by using one or more of the +validate+, +validate_on_create+ or +validate_on_update+ class methods, passing in the symbols for the validation methods' names. +You can also create methods that verify the state of your models and add messages to the +errors+ collection when they are invalid. You must then register these methods by using the +validate+ class method, passing in the symbols for the validation methods' names. You can pass more than one symbol for each class method and the respective validations will be run in the same order as they were registered. @@ -637,12 +637,24 @@ class Invoice < ActiveRecord::Base end </ruby> +By default such validations will run every time you call +valid?+. It is also possible to control when to run these custom validations by giving an +:on+ option to the +validate+ method, with either: +:create+ or +:update+. + +<ruby> +class Invoice < ActiveRecord::Base + validate :active_customer, :on => :create + + def active_customer + errors.add(:customer_id, "is not active") unless customer.active? + end +end +</ruby> + You can even create your own validation helpers and reuse them in several different models. For example, an application that manages surveys may find it useful to express that a certain field corresponds to a set of choices: <ruby> ActiveRecord::Base.class_eval do def self.validates_as_choice(attr_name, n, options={}) - validates attr_name, :inclusion => { {:in => 1..n}.merge(options) } + validates attr_name, :inclusion => { { :in => 1..n }.merge!(options) } end end </ruby> @@ -659,7 +671,7 @@ h3. Working with Validation Errors In addition to the +valid?+ and +invalid?+ methods covered earlier, Rails provides a number of methods for working with the +errors+ collection and inquiring about the validity of objects. -The following is a list of the most commonly used methods. Please refer to the +ActiveRecord::Errors+ documentation for a list of all the available methods. +The following is a list of the most commonly used methods. Please refer to the +ActiveModel::Errors+ documentation for a list of all the available methods. h4(#working_with_validation_errors-errors). +errors+ @@ -796,17 +808,9 @@ person.errors.size # => 0 h3. Displaying Validation Errors in the View -Rails maintains an official plugin, DynamicForm, 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. +"DynamicForm":https://github.com/joelmoss/dynamic_form provides helpers to display the error messages of your models in your view templates. -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 in your Gemfile: +You can install it as a gem by adding this line to your Gemfile: <ruby> gem "dynamic_form" @@ -897,13 +901,8 @@ Below is a simple example where we change the Rails behavior to always display t <ruby> ActionView::Base.field_error_proc = Proc.new do |html_tag, instance| - if instance.error_message.kind_of?(Array) - %(#{html_tag}<span class="validation-error"> - #{instance.error_message.join(',')}</span>).html_safe - else - %(#{html_tag}<span class="validation-error"> - #{instance.error_message}</span>).html_safe - end + errors = Array(instance.error_message).join(',') + %(#{html_tag}<span class="validation-error"> #{errors}</span>).html_safe end </ruby> @@ -957,6 +956,7 @@ h4. Creating an Object * +before_validation+ * +after_validation+ * +before_save+ +* +around_save+ * +before_create+ * +around_create+ * +after_create+ @@ -967,6 +967,7 @@ h4. Updating an Object * +before_validation+ * +after_validation+ * +before_save+ +* +around_save+ * +before_update+ * +around_update+ * +after_update+ @@ -975,8 +976,8 @@ h4. Updating an Object h4. Destroying an Object * +before_destroy+ -* +after_destroy+ * +around_destroy+ +* +after_destroy+ WARNING. +after_save+ runs both on create and update, but always _after_ the more specific callbacks +after_create+ and +after_update+, no matter the order in which the macro calls were executed. @@ -986,15 +987,15 @@ The +after_initialize+ callback will be called whenever an Active Record object The +after_find+ callback will be called whenever Active Record loads a record from the database. +after_find+ is called before +after_initialize+ if both are defined. -The +after_initialize+ and +after_find+ callbacks are a bit different from the others. They have no +before_*+ counterparts, and they are registered simply by defining them as regular methods with predefined names. If you try to register +after_initialize+ or +after_find+ using macro-style class methods, they will just be ignored. This behavior is due to performance reasons, since +after_initialize+ and +after_find+ will both be called for each record found in the database, which would otherwise significantly slow down the queries. +The +after_initialize+ and +after_find+ callbacks have no +before_*+ counterparts, but they can be registered just like the other Active Record callbacks. <ruby> class User < ActiveRecord::Base - def after_initialize + after_initialize do |user| puts "You have initialized an object!" end - def after_find + after_find do |user| puts "You have found an object!" end end @@ -1021,7 +1022,7 @@ The following methods trigger callbacks: * +increment!+ * +save+ * +save!+ -* +save(false)+ +* +save(:validate => false)+ * +toggle!+ * +update+ * +update_attribute+ |