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author | Jaime Iniesta <jaimeiniesta@gmail.com> | 2010-04-07 17:56:51 +0200 |
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committer | Xavier Noria <fxn@hashref.com> | 2010-04-09 04:45:03 -0700 |
commit | 647addd8e022012b159bc2298c5e23b5c8ff315c (patch) | |
tree | ee81b0db93e8ece7991b7f9b77bdc61b087eed51 /railties/guides/source | |
parent | 4f0982db91f4e67b36aec7f1e7445655e7bce8ce (diff) | |
download | rails-647addd8e022012b159bc2298c5e23b5c8ff315c.tar.gz rails-647addd8e022012b159bc2298c5e23b5c8ff315c.tar.bz2 rails-647addd8e022012b159bc2298c5e23b5c8ff315c.zip |
Fixed duplicated IDs on associations_basics guide to validate XHTML 1.0 Strict
Diffstat (limited to 'railties/guides/source')
-rw-r--r-- | railties/guides/source/association_basics.textile | 163 |
1 files changed, 82 insertions, 81 deletions
diff --git a/railties/guides/source/association_basics.textile b/railties/guides/source/association_basics.textile index 4256466bec..f13f6db6ee 100644 --- a/railties/guides/source/association_basics.textile +++ b/railties/guides/source/association_basics.textile @@ -603,11 +603,11 @@ The +belongs_to+ association supports these options: * +:touch+ * +:validate+ -h6. +:autosave+ +h6(#belongs_to-autosave). +:autosave+ If you set the +:autosave+ option to +true+, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. -h6. +:class_name+ +h6(#belongs_to-class_name). +:class_name+ If the name of the other model cannot be derived from the association name, you can use the +:class_name+ option to supply the model name. For example, if an order belongs to a customer, but the actual name of the model containing customers is +Patron+, you'd set things up this way: @@ -617,7 +617,7 @@ class Order < ActiveRecord::Base end </ruby> -h6. +:conditions+ +h6(#belongs_to-conditions). +:conditions+ The +:conditions+ option lets you specify the conditions that the associated object must meet (in the syntax used by a SQL +WHERE+ clause). @@ -666,13 +666,13 @@ end Counter cache columns are added to the containing model's list of read-only attributes through +attr_readonly+. -h6. +:dependent+ +h6(#belongs_to-dependent). +:dependent+ If you set the +:dependent+ option to +:destroy+, then deleting this object will call the +destroy+ method on the associated object to delete that object. If you set the +:dependent+ option to +:delete+, then deleting this object will delete the associated object _without_ calling its +destroy+ method. WARNING: You should not specify this option on a +belongs_to+ association that is connected with a +has_many+ association on the other class. Doing so can lead to orphaned records in your database. -h6. +:foreign_key+ +h6(#belongs_to-foreign_key). +:foreign_key+ By convention, Rails guesses that the column used to hold the foreign key on this model is the name of the association with the suffix +_id+ added. The +:foreign_key+ option lets you set the name of the foreign key directly: @@ -685,7 +685,7 @@ end TIP: In any case, Rails will not create foreign key columns for you. You need to explicitly define them as part of your migrations. -h6. +:include+ +h6(#belongs_to-includes). +:include+ You can use the +:include+ option to specify second-order associations that should be eager-loaded when this association is used. For example, consider these models: @@ -727,11 +727,11 @@ h6. +:polymorphic+ Passing +true+ to the +:polymorphic+ option indicates that this is a polymorphic association. Polymorphic associations were discussed in detail <a href="#polymorphic-associations">earlier in this guide</a>. -h6. +:readonly+ +h6(#belongs_to-readonly). +:readonly+ If you set the +:readonly+ option to +true+, then the associated object will be read-only when retrieved via the association. -h6. +:select+ +h6(#belongs_to-select). +:select+ The +:select+ option lets you override the SQL +SELECT+ clause that is used to retrieve data about the associated object. By default, Rails retrieves all columns. @@ -759,11 +759,11 @@ class Order < ActiveRecord::Base end </ruby> -h6. +:validate+ +h6(#belongs_to-validate). +:validate+ If you set the +:validate+ option to +true+, then associated objects will be validated whenever you save this object. By default, this is +false+: associated objects will not be validated when this object is saved. -h5. How To Know Whether There's an Associated Object? +h5(#belongs_to-how_to_know_whether_theres_an_associated_object). How To Know Whether There's an Associated Object? To know whether there's and associated object just check <tt><em>association</em>.nil?</tt>: @@ -773,7 +773,7 @@ if @order.customer.nil? end </ruby> -h5. When are Objects Saved? +h5(#belongs_to-when_are_objects_saved). When are Objects Saved? Assigning an object to a +belongs_to+ association does _not_ automatically save the object. It does not save the associated object either. @@ -869,15 +869,15 @@ The +has_one+ association supports these options: * +:through+ * +:validate+ -h6. +:as+ +h6(#has_one-as). +:as+ Setting the +:as+ option indicates that this is a polymorphic association. Polymorphic associations were discussed in detail <a href="#polymorphic-associations">earlier in this guide</a>. -h6. +:autosave+ +h6(#has_one-autosave). +:autosave+ If you set the +:autosave+ option to +true+, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. -h6. +:class_name+ +h6(#has_one-class_name). +:class_name+ If the name of the other model cannot be derived from the association name, you can use the +:class_name+ option to supply the model name. For example, if a supplier has an account, but the actual name of the model containing accounts is +Billing+, you'd set things up this way: @@ -887,7 +887,7 @@ class Supplier < ActiveRecord::Base end </ruby> -h6. +:conditions+ +h6(#has_one-conditions). +:conditions+ The +:conditions+ option lets you specify the conditions that the associated object must meet (in the syntax used by a SQL +WHERE+ clause). @@ -897,11 +897,11 @@ class Supplier < ActiveRecord::Base end </ruby> -h6. +:dependent+ +h6(#has_one-dependent). +:dependent+ If you set the +:dependent+ option to +:destroy+, then deleting this object will call the +destroy+ method on the associated object to delete that object. If you set the +:dependent+ option to +:delete+, then deleting this object will delete the associated object _without_ calling its +destroy+ method. If you set the +:dependent+ option to +:nullify+, then deleting this object will set the foreign key in the association object to +NULL+. -h6. +:foreign_key+ +h6(#has_one-foreign_key). +:foreign_key+ By convention, Rails guesses that the column used to hold the foreign key on the other model is the name of this model with the suffix +_id+ added. The +:foreign_key+ option lets you set the name of the foreign key directly: @@ -913,7 +913,7 @@ end TIP: In any case, Rails will not create foreign key columns for you. You need to explicitly define them as part of your migrations. -h6. +:include+ +h6(#has_one-include). +:include+ You can use the +:include+ option to specify second-order associations that should be eager-loaded when this association is used. For example, consider these models: @@ -949,39 +949,39 @@ class Representative < ActiveRecord::Base end </ruby> -h6. +:order+ +h6(#has_one-order). +:order+ The +:order+ option dictates the order in which associated objects will be received (in the syntax used by a SQL +ORDER BY+ clause). Because a +has_one+ association will only retrieve a single associated object, this option should not be needed. -h6. +:primary_key+ +h6(#has_one-primary_key). +:primary_key+ By convention, Rails guesses that the column used to hold the primary key of this model is +id+. You can override this and explicitly specify the primary key with the +:primary_key+ option. -h6. +:readonly+ +h6(#has_one-readonly). +:readonly+ If you set the +:readonly+ option to +true+, then the associated object will be read-only when retrieved via the association. -h6. +:select+ +h6(#has_one-select). +:select+ The +:select+ option lets you override the SQL +SELECT+ clause that is used to retrieve data about the associated object. By default, Rails retrieves all columns. -h6. +:source+ +h6(#has_one-source). +:source+ The +:source+ option specifies the source association name for a +has_one :through+ association. -h6. +:source_type+ +h6(#has_one-source_type). +:source_type+ The +:source_type+ option specifies the source association type for a +has_one :through+ association that proceeds through a polymorphic association. -h6. +:through+ +h6(#has_one-through). +:through+ The +:through+ option specifies a join model through which to perform the query. +has_one :through+ associations were discussed in detail <a href="#the-has-one-through-association">earlier in this guide</a>. -h6. +:validate+ +h6(#has_one-validate). +:validate+ If you set the +:validate+ option to +true+, then associated objects will be validated whenever you save this object. By default, this is +false+: associated objects will not be validated when this object is saved. -h5. How To Know Whether There's an Associated Object? +h5(#has_one-how_to_know_whether_theres_an_associated_object). How To Know Whether There's an Associated Object? To know whether there's and associated object just check <tt><em>association</em>.nil?</tt>: @@ -991,7 +991,7 @@ if @supplier.account.nil? end </ruby> -h5. When are Objects Saved? +h5(#has_one-when_are_objects_saved). When are Objects Saved? When you assign an object to a +has_one+ association, that object is automatically saved (in order to update its foreign key). In addition, any object being replaced is also automatically saved, because its foreign key will change too. @@ -1005,7 +1005,7 @@ h4. +has_many+ Association Reference The +has_many+ association creates a one-to-many relationship with another model. In database terms, this association says that the other class will have a foreign key that refers to instances of this class. -h5. Methods Added +h5. Methods Added by +has_many+ When you declare a +has_many+ association, the declaring class automatically gains 13 methods related to the association: @@ -1049,7 +1049,7 @@ orders.build(attributes = {}, ...) orders.create(attributes = {}) </ruby> -h6. <tt><em>collection</em>(force_reload = false)</tt> +h6(#has_many-collection). <tt><em>collection</em>(force_reload = false)</tt> The <tt><em>collection</em></tt> method returns an array of all of the associated objects. If there are no associated objects, it returns an empty array. @@ -1057,7 +1057,7 @@ The <tt><em>collection</em></tt> method returns an array of all of the associate @orders = @customer.orders </ruby> -h6. <tt><em>collection</em><<(object, ...)</tt> +h6(#has_many-collection-lt_lt). <tt><em>collection</em><<(object, ...)</tt> The <tt><em>collection</em><<</tt> method adds one or more objects to the collection by setting their foreign keys to the primary key of the calling model. @@ -1065,7 +1065,7 @@ The <tt><em>collection</em><<</tt> method adds one or more objects to the collec @customer.orders << @order1 </ruby> -h6. <tt><em>collection</em>.delete(object, ...)</tt> +h6(#has_many-collection-delete). <tt><em>collection</em>.delete(object, ...)</tt> The <tt><em>collection</em>.delete</tt> method removes one or more objects from the collection by setting their foreign keys to +NULL+. @@ -1076,11 +1076,11 @@ The <tt><em>collection</em>.delete</tt> method removes one or more objects from WARNING: Objects will be in addition destroyed if they're associated with +:dependent => :destroy+, and deleted if they're associated with +:dependent => :delete_all+. -h6. <tt><em>collection</em>=objects</tt> +h6(#has_many-collection_equal). <tt><em>collection</em>=objects</tt> The <tt><em>collection</em>=</tt> method makes the collection contain only the supplied objects, by adding and deleting as appropriate. -h6. <tt><em>collection_singular</em>_ids</tt> +h6(#has_many-collection_singular). <tt><em>collection_singular</em>_ids</tt> The <tt><em>collection_singular</em>_ids</tt> method returns an array of the ids of the objects in the collection. @@ -1088,11 +1088,11 @@ The <tt><em>collection_singular</em>_ids</tt> method returns an array of the ids @order_ids = @customer.order_ids </ruby> -h6. <tt><em>collection_singular</em>_ids=ids</tt> +h6(#has_many-collection_singular_ids_ids). <tt><em>collection_singular</em>_ids=ids</tt> The <tt><em>collection_singular</em>_ids=</tt> method makes the collection contain only the objects identified by the supplied primary key values, by adding and deleting as appropriate. -h6. <tt><em>collection</em>.clear</tt> +h6(#has_many-collection_clear). <tt><em>collection</em>.clear</tt> The <tt><em>collection</em>.clear</tt> method removes every object from the collection. This destroys the associated objects if they are associated with +:dependent => :destroy+, deletes them directly from the database if +:dependent => :delete_all+, and otherwise sets their foreign keys to +NULL+. @@ -1179,7 +1179,7 @@ The +has_many+ association supports these options: * +:uniq+ * +:validate+ -h6. +:as+ +h6(#has_many-as). +:as+ Setting the +:as+ option indicates that this is a polymorphic association, as discussed <a href="#polymorphic-associations">earlier in this guide</a>. @@ -1187,7 +1187,7 @@ h6. +:autosave+ If you set the +:autosave+ option to +true+, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. -h6. +:class_name+ +h6(#has_many-class_name). +:class_name+ If the name of the other model cannot be derived from the association name, you can use the +:class_name+ option to supply the model name. For example, if a customer has many orders, but the actual name of the model containing orders is +Transaction+, you'd set things up this way: @@ -1197,7 +1197,7 @@ class Customer < ActiveRecord::Base end </ruby> -h6. +:conditions+ +h6(#has_many-conditions). +:conditions+ The +:conditions+ option lets you specify the conditions that the associated object must meet (in the syntax used by a SQL +WHERE+ clause). @@ -1230,27 +1230,27 @@ end Be sure to use single quotes. -h6. +:counter_sql+ +h6(#has_many-counter_sql). +:counter_sql+ Normally Rails automatically generates the proper SQL to count the association members. With the +:counter_sql+ option, you can specify a complete SQL statement to count them yourself. NOTE: If you specify +:finder_sql+ but not +:counter_sql+, then the counter SQL will be generated by substituting +SELECT COUNT(*) FROM+ for the +SELECT ... FROM+ clause of your +:finder_sql+ statement. -h6. +:dependent+ +h6(#has_many-dependent). +:dependent+ If you set the +:dependent+ option to +:destroy+, then deleting this object will call the +destroy+ method on the associated objects to delete those objects. If you set the +:dependent+ option to +:delete_all+, then deleting this object will delete the associated objects _without_ calling their +destroy+ method. If you set the +:dependent+ option to +:nullify+, then deleting this object will set the foreign key in the associated objects to +NULL+. NOTE: This option is ignored when you use the +:through+ option on the association. -h6. +:extend+ +h6(#has_many-extend). +:extend+ The +:extend+ option specifies a named module to extend the association proxy. Association extensions are discussed in detail <a href="#association-extensions">later in this guide</a>. -h6. +:finder_sql+ +h6(#has_many-finder_sql). +:finder_sql+ Normally Rails automatically generates the proper SQL to fetch the association members. With the +:finder_sql+ option, you can specify a complete SQL statement to fetch them yourself. If fetching objects requires complex multi-table SQL, this may be necessary. -h6. +:foreign_key+ +h6(#has_many-foreign_key). +:foreign_key+ By convention, Rails guesses that the column used to hold the foreign key on the other model is the name of this model with the suffix +_id+ added. The +:foreign_key+ option lets you set the name of the foreign key directly: @@ -1262,7 +1262,7 @@ end TIP: In any case, Rails will not create foreign key columns for you. You need to explicitly define them as part of your migrations. -h6. +:group+ +h6(:has_many-group). +:group+ The +:group+ option supplies an attribute name to group the result set by, using a +GROUP BY+ clause in the finder SQL. @@ -1272,7 +1272,7 @@ class Customer < ActiveRecord::Base end </ruby> -h6. +:include+ +h6(#has_many-include). +:include+ You can use the +:include+ option to specify second-order associations that should be eager-loaded when this association is used. For example, consider these models: @@ -1308,7 +1308,7 @@ class LineItem < ActiveRecord::Base end </ruby> -h6. +:limit+ +h6(#has_many-limit). +:limit+ The +:limit+ option lets you restrict the total number of objects that will be fetched through an association. @@ -1319,11 +1319,11 @@ class Customer < ActiveRecord::Base end </ruby> -h6. +:offset+ +h6(#has_many-offset). +:offset+ The +:offset+ option lets you specify the starting offset for fetching objects via an association. For example, if you set +:offset => 11+, it will skip the first 11 records. -h6. +:order+ +h6(#has_many-order). +:order+ The +:order+ option dictates the order in which associated objects will be received (in the syntax used by a SQL +ORDER BY+ clause). @@ -1333,41 +1333,41 @@ class Customer < ActiveRecord::Base end </ruby> -h6. +:primary_key+ +h6(#has_many-primary_key). +:primary_key+ By convention, Rails guesses that the column used to hold the primary key of the association is +id+. You can override this and explicitly specify the primary key with the +:primary_key+ option. -h6. +:readonly+ +h6(#has_many-readonly). +:readonly+ If you set the +:readonly+ option to +true+, then the associated objects will be read-only when retrieved via the association. -h6. +:select+ +h6(#has_many-select). +:select+ The +:select+ option lets you override the SQL +SELECT+ clause that is used to retrieve data about the associated objects. By default, Rails retrieves all columns. WARNING: If you specify your own +:select+, be sure to include the primary key and foreign key columns of the associated model. If you do not, Rails will throw an error. -h6. +:source+ +h6(#has_many-source). +:source+ The +:source+ option specifies the source association name for a +has_many :through+ association. You only need to use this option if the name of the source association cannot be automatically inferred from the association name. -h6. +:source_type+ +h6(#has_many-source_type). +:source_type+ The +:source_type+ option specifies the source association type for a +has_many :through+ association that proceeds through a polymorphic association. -h6. +:through+ +h6(#has_many-through). +:through+ The +:through+ option specifies a join model through which to perform the query. +has_many :through+ associations provide a way to implement many-to-many relationships, as discussed <a href="#the-has-many-through-association">earlier in this guide</a>. -h6. +:uniq+ +h6(#has_many-uniq). +:uniq+ Specify the +:uniq => true+ option to remove duplicates from the collection. This is most useful in conjunction with the +:through+ option. -h6. +:validate+ +h6(#has_many-validate). +:validate+ If you set the +:validate+ option to +false+, then associated objects will not be validated whenever you save this object. By default, this is +true+: associated objects will be validated when this object is saved. -h5. When are Objects Saved? +h5(#has_many-when_are_objects_saved). When are Objects Saved? When you assign an object to a +has_many+ association, that object is automatically saved (in order to update its foreign key). If you assign multiple objects in one statement, then they are all saved. @@ -1381,7 +1381,7 @@ h4. +has_and_belongs_to_many+ Association Reference The +has_and_belongs_to_many+ association creates a many-to-many relationship with another model. In database terms, this associates two classes via an intermediate join table that includes foreign keys referring to each of the classes. -h5. Methods Added +h5. Methods Added by +has_and_belongs_to_many+ When you declare a +has_and_belongs_to_many+ association, the declaring class automatically gains 13 methods related to the association: @@ -1478,7 +1478,7 @@ h6. <tt><em>collection</em>.clear</tt> The <tt><em>collection</em>.clear</tt> method removes every object from the collection by deleting the rows from the joining table. This does not destroy the associated objects. -h6. <tt><em>collection</em>.empty?</tt> +h6(#has_and_belongs_to_many-collection-empty). <tt><em>collection</em>.empty?</tt> The <tt><em>collection</em>.empty?</tt> method returns +true+ if the collection does not contain any associated objects. @@ -1488,7 +1488,7 @@ The <tt><em>collection</em>.empty?</tt> method returns +true+ if the collection <% end %> </ruby> -h6. <tt><em>collection</em>.size</tt> +h6(#has_and_belongs_to_many-collection-size). <tt><em>collection</em>.size</tt> The <tt><em>collection</em>.size</tt> method returns the number of objects in the collection. @@ -1496,7 +1496,7 @@ The <tt><em>collection</em>.size</tt> method returns the number of objects in th @assembly_count = @part.assemblies.size </ruby> -h6. <tt><em>collection</em>.find(...)</tt> +h6(#has_and_belongs_to_many-collection-find). <tt><em>collection</em>.find(...)</tt> The <tt><em>collection</em>.find</tt> method finds objects within the collection. It uses the same syntax and options as +ActiveRecord::Base.find+. It also adds the additional condition that the object must be in the collection. @@ -1505,7 +1505,7 @@ The <tt><em>collection</em>.find</tt> method finds objects within the collection :conditions => ["created_at > ?", 2.days.ago]) </ruby> -h6. <tt><em>collection</em>.exists?(...)</tt> +h6(#has_and_belongs_to_many-collection-exists). <tt><em>collection</em>.exists?(...)</tt> The <tt><em>collection</em>.exists?</tt> method checks whether an object meeting the supplied conditions exists in the collection. It uses the same syntax and options as +ActiveRecord::Base.exists?+. @@ -1518,7 +1518,7 @@ The <tt><em>collection</em>.build</tt> method returns a new object of the associ {:assembly_name => "Transmission housing"}) </ruby> -h6. <tt><em>collection</em>.create(attributes = {})</tt> +h6(#has_and_belongs_to_many-create-attributes). <tt><em>collection</em>.create(attributes = {})</tt> The <tt><em>collection</em>.create</tt> method returns a new object of the associated type. This object will be instantiated from the passed attributes, the link through the join table will be created, and the associated object _will_ be saved (assuming that it passes any validations). @@ -1575,11 +1575,11 @@ class User < ActiveRecord::Base end </ruby> -h6. +:autosave+ +h6(#has_and_belongs_to_many-autosave). +:autosave+ If you set the +:autosave+ option to +true+, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. -h6. +:class_name+ +h6(#has_and_belongs_to_many-class_name). +:class_name+ If the name of the other model cannot be derived from the association name, you can use the +:class_name+ option to supply the model name. For example, if a part has many assemblies, but the actual name of the model containing assemblies is +Gadget+, you'd set things up this way: @@ -1589,7 +1589,7 @@ class Parts < ActiveRecord::Base end </ruby> -h6. +:conditions+ +h6(#has_and_belongs_to_many-conditions). +:conditions+ The +:conditions+ option lets you specify the conditions that the associated object must meet (in the syntax used by a SQL +WHERE+ clause). @@ -1611,7 +1611,7 @@ end If you use a hash-style +:conditions+ option, then record creation via this association will be automatically scoped using the hash. In this case, using +@parts.assemblies.create+ or +@parts.assemblies.build+ will create orders where the +factory+ column has the value "Seattle". -h6. +:counter_sql+ +h6(#has_and_belongs_to_many-counter_sql). +:counter_sql+ Normally Rails automatically generates the proper SQL to count the association members. With the +:counter_sql+ option, you can specify a complete SQL statement to count them yourself. @@ -1621,15 +1621,15 @@ h6. +:delete_sql+ Normally Rails automatically generates the proper SQL to remove links between the associated classes. With the +:delete_sql+ option, you can specify a complete SQL statement to delete them yourself. -h6. +:extend+ +h6(#has_and_belongs_to_many-extend). +:extend+ The +:extend+ option specifies a named module to extend the association proxy. Association extensions are discussed in detail <a href="#association-extensions">later in this guide</a>. -h6. +:finder_sql+ +h6(#has_and_belongs_to_many-finder_sql). +:finder_sql+ Normally Rails automatically generates the proper SQL to fetch the association members. With the +:finder_sql+ option, you can specify a complete SQL statement to fetch them yourself. If fetching objects requires complex multi-table SQL, this may be necessary. -h6. +:foreign_key+ +h6(#has_and_belongs_to_many-foreign_key). +:foreign_key+ By convention, Rails guesses that the column in the join table used to hold the foreign key pointing to this model is the name of this model with the suffix +_id+ added. The +:foreign_key+ option lets you set the name of the foreign key directly: @@ -1641,7 +1641,7 @@ class User < ActiveRecord::Base end </ruby> -h6. +:group+ +h6(#has_and_belongs_to_many-group). +:group+ The +:group+ option supplies an attribute name to group the result set by, using a +GROUP BY+ clause in the finder SQL. @@ -1651,7 +1651,7 @@ class Parts < ActiveRecord::Base end </ruby> -h6. +:include+ +h6(#has_and_belongs_to_many-include). +:include+ You can use the +:include+ option to specify second-order associations that should be eager-loaded when this association is used. @@ -1663,7 +1663,7 @@ h6. +:join_table+ If the default name of the join table, based on lexical ordering, is not what you want, you can use the +:join_table+ option to override the default. -h6. +:limit+ +h6(#has_and_belongs_to_many-limit). +:limit+ The +:limit+ option lets you restrict the total number of objects that will be fetched through an association. @@ -1674,11 +1674,11 @@ class Parts < ActiveRecord::Base end </ruby> -h6. +:offset+ +h6(#has_and_belongs_to_many-offset). +:offset+ The +:offset+ option lets you specify the starting offset for fetching objects via an association. For example, if you set +:offset => 11+, it will skip the first 11 records. -h6. +:order+ +h6(#has_and_belongs_to_many-order). +:order+ The +:order+ option dictates the order in which associated objects will be received (in the syntax used by a SQL +ORDER BY+ clause). @@ -1688,23 +1688,23 @@ class Parts < ActiveRecord::Base end </ruby> -h6. +:readonly+ +h6(#has_and_belongs_to_many-readonly). +:readonly+ If you set the +:readonly+ option to +true+, then the associated objects will be read-only when retrieved via the association. -h6. +:select+ +h6(#has_and_belongs_to_many-select). +:select+ The +:select+ option lets you override the SQL +SELECT+ clause that is used to retrieve data about the associated objects. By default, Rails retrieves all columns. -h6. +:uniq+ +h6(#has_and_belongs_to_many-uniq). +:uniq+ Specify the +:uniq => true+ option to remove duplicates from the collection. -h6. +:validate+ +h6(#has_and_belongs_to_many-validate). +:validate+ If you set the +:validate+ option to +false+, then associated objects will not be validated whenever you save this object. By default, this is +true+: associated objects will be validated when this object is saved. -h5. When are Objects Saved? +h5(#has_and_belongs_to_many-when_are_objects_saved). When are Objects Saved? When you assign an object to a +has_and_belongs_to_many+ association, that object is automatically saved (in order to update the join table). If you assign multiple objects in one statement, then they are all saved. @@ -1809,6 +1809,7 @@ h3. Changelog "Lighthouse ticket":http://rails.lighthouseapp.com/projects/16213-rails-guides/tickets/11 +* April 7, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com * April 19, 2009: Added +:touch+ option to +belongs_to+ associations by "Mike Gunderloy":credits.html#mgunderloy * February 1, 2009: Added +:autosave+ option "Mike Gunderloy":credits.html#mgunderloy * September 28, 2008: Corrected +has_many :through+ diagram, added polymorphic diagram, some reorganization by "Mike Gunderloy":credits.html#mgunderloy . First release version. |