Rails 3 Model - Revision history

Scott: /* simple join */

2011-09-08T21:40:24Z

simple join

← Older revision		Revision as of 21:40, 8 September 2011
Line 185:		Line 185:
	has_and_belongs_to_many :articles		has_and_belongs_to_many :articles
	end		end
			</source>

			To add/drop an association:
			<source lang="ruby">
			user.articles.push(category)
			user.articles.delete(category)
	</source>		</source>

2011-06-30T20:24:18Z

Observer

@@ Line 394: / Line 394: @@
 # Activate observers that should always be running
 config.active_record.observers = :comment_observer
 </source>

2011-06-30T20:10:22Z

Callbacks

@@ Line 360: / Line 360: @@
 See error message with <code>comment.errors.full_messages</code>
-== Callbacks ==
+== Callbacks and Observers ==
 <source lang="ruby">
 class Comment < ActiveRecord::Base
@@ Line 372: / Line 374: @@
 <source lang="ruby">
 before_create, after_create, before_save, after_save, before_destroy, after_destroy
 </source>

2011-06-30T20:04:10Z

Custom Validations

← Older revision		Revision as of 20:04, 30 June 2011
Line 359:		Line 359:
	</source>		</source>
	See error message with <code>comment.errors.full_messages</code>		See error message with <code>comment.errors.full_messages</code>

			== Callbacks ==
			<source lang="ruby">
			class Comment < ActiveRecord::Base
			after_create :email_article_author
			def email_article_author
			puts "We will notify #{article.user.email} in Chapter 9"
			end
			end
			</source>
			Other callbacks:
			<source lang="ruby">
			before_create, after_create, before_save, after_save, before_destroy, after_destroy
			</source>

2011-06-30T20:00:15Z

Validation and Errors

← Older revision		Revision as of 20:00, 30 June 2011
Line 275:		Line 275:
	</source>		</source>

	== Validation ~~and Errors~~ ==		== Validation ==
	<source lang="ruby">		<source lang="ruby">
	class Article< ActiveRecord::Base		class Article< ActiveRecord::Base

2011-06-30T18:51:01Z

Custom Validations

← Older revision		Revision as of 18:51, 30 June 2011
Line 358:		Line 358:
	end		end
	</source>		</source>
			See error message with <code>comment.errors.full_messages</code>

2011-06-30T18:50:21Z

Custom Validations

← Older revision		Revision as of 18:50, 30 June 2011
Line 340:		Line 340:
	=== Custom Validations ===		=== Custom Validations ===
	<source lang="ruby">		<source lang="ruby">
	def published?		class Article < ActiveRecord::Base
	published_at.present?		...
			def published?
			published_at.present?
			end
	end		end
	</source>		</source>

2011-06-30T18:49:48Z

Length validation options

← Older revision		Revision as of 18:49, 30 June 2011
Line 337:		Line 337:
	\|----		\|----
	\|}		\|}

			=== Custom Validations ===
			<source lang="ruby">
			def published?
			published_at.present?
			end
			</source>

			<source lang="ruby">
			class Comment < ActiveRecord::Base
			belongs_to :article
			validates :name, :email, :body, :presence => true
			validate :article_should_be_published # not "validates"
			def article_should_be_published
			errors.add(:article_id, "is not published yet") if article && !article.published?
			end
			end
			</source>

2011-06-30T18:42:29Z

Validation and Errors

2011-06-30T18:41:36Z

Validation and Errors

← Older revision		Revision as of 18:41, 30 June 2011
Line 303:		Line 303:
	end		end
	</source>		</source>

			{\|border=1 cellpadding=5
			\|Option
			\|Description
			\|----
			\|:minimum
			\|Specifies the minimum size of the attribute
			\|----
			\|:maximum
			\|Specifies the maximum size of the attribute
			\|----
			\|:is
			\|Specifies the exact size of the attribute
			\|----
			\|:within
			\|Specifies the valid range (as a Ruby Range object) of values acceptable for the attribute
			\|----
			\|:allow_nil
			\|Specifies that the attribute may be nil; if so, the validation is skipped
			\|----
			\|:too_long
			\|Specifies the error message to add if the attribute exceeds the maximum
			\|----
			\|:too_short
			\|Specifies the error message to add if the attribute is below the minimum
			\|----
			\|:wrong_length
			\|Specifies the error message to add if the attribute is of the wrong size
			\|----
			\|:message
			\|Specifies the error message to add if :minimum, :maximum, or :is is violated
			\|----
			\|}