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Improve readability of ActiveRecord::Assocations.has_many's documenta…

…tion.
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1 parent 03afe79 commit 4d719c185ac17d30c624add296872111570bf5b6 @FooBarWidget FooBarWidget committed Jul 18, 2008
Showing with 89 additions and 44 deletions.
  1. +89 −44 activerecord/lib/active_record/associations.rb
@@ -150,6 +150,7 @@ def clear_association_cache #:nodoc:
# #others.destroy_all | X | X | X
# #others.find(*args) | X | X | X
# #others.find_first | X | |
+ # #others.exist? | X | X | X
# #others.uniq | X | X | X
# #others.reset | X | X | X
#
@@ -612,31 +613,53 @@ def clear_association_cache #:nodoc:
# All of the association macros can be specialized through options. This makes cases more complex than the simple and guessable ones
# possible.
module ClassMethods
- # Adds the following methods for retrieval and query of collections of associated objects:
- # +collection+ is replaced with the symbol passed as the first argument, so
- # <tt>has_many :clients</tt> would add among others <tt>clients.empty?</tt>.
- # * <tt>collection(force_reload = false)</tt> - Returns an array of all the associated objects.
+ # Specifies a one-to-many association. The following methods for retrieval and query of
+ # collections of associated objects will be added:
+ #
+ # [collection(force_reload = false)]
+ # Returns an array of all the associated objects.
# An empty array is returned if none are found.
- # * <tt>collection<<(object, ...)</tt> - Adds one or more objects to the collection by setting their foreign keys to the collection's primary key.
- # * <tt>collection.delete(object, ...)</tt> - Removes one or more objects from the collection by setting their foreign keys to +NULL+.
+ # [collection<<(object, ...)]
+ # Adds one or more objects to the collection by setting their foreign keys to the collection's primary key.
+ # [collection.delete(object, ...)]
+ # Removes one or more objects from the collection by setting their foreign keys to +NULL+.
# This will also destroy the objects if they're declared as +belongs_to+ and dependent on this model.
- # * <tt>collection=objects</tt> - Replaces the collections content by deleting and adding objects as appropriate.
- # * <tt>collection_singular_ids</tt> - Returns an array of the associated objects' ids
- # * <tt>collection_singular_ids=ids</tt> - Replace the collection with the objects identified by the primary keys in +ids+
- # * <tt>collection.clear</tt> - Removes every object from the collection. This destroys the associated objects if they
- # are associated with <tt>:dependent => :destroy</tt>, deletes them directly from the database if <tt>:dependent => :delete_all</tt>,
- # otherwise sets their foreign keys to +NULL+.
- # * <tt>collection.empty?</tt> - Returns +true+ if there are no associated objects.
- # * <tt>collection.size</tt> - Returns the number of associated objects.
- # * <tt>collection.find</tt> - Finds an associated object according to the same rules as Base.find.
- # * <tt>collection.build(attributes = {}, ...)</tt> - Returns one or more new objects of the collection type that have been instantiated
- # with +attributes+ and linked to this object through a foreign key, but have not yet been saved. *Note:* This only works if an
- # associated object already exists, not if it's +nil+!
- # * <tt>collection.create(attributes = {})</tt> - Returns a new object of the collection type that has been instantiated
- # with +attributes+, linked to this object through a foreign key, and that has already been saved (if it passed the validation).
- # *Note:* This only works if an associated object already exists, not if it's +nil+!
+ # [collection=objects]
+ # Replaces the collections content by deleting and adding objects as appropriate.
+ # [collection_singular_ids]
+ # Returns an array of the associated objects' ids
+ # [collection_singular_ids=ids]
+ # Replace the collection with the objects identified by the primary keys in +ids+
+ # [collection.clear]
+ # Removes every object from the collection. This destroys the associated objects if they
+ # are associated with <tt>:dependent => :destroy</tt>, deletes them directly from the
+ # database if <tt>:dependent => :delete_all</tt>, otherwise sets their foreign keys to +NULL+.
+ # [collection.empty?]
+ # Returns +true+ if there are no associated objects.
+ # [collection.size]
+ # Returns the number of associated objects.
+ # [collection.find(...)]
+ # Finds an associated object according to the same rules as Base.find.
+ # [collection.exist?(...)]
+ # Checks whether an associated object with the given conditions exists.
+ # Uses the same rules as Base.exists?.
+ # [collection.build(attributes = {}, ...)]
+ # Returns one or more new objects of the collection type that have been instantiated
+ # with +attributes+ and linked to this object through a foreign key, but have not yet
+ # been saved. *Note:* This only works if an associated object already exists, not if
+ # it's +nil+!
+ # [collection.create(attributes = {})]
+ # Returns a new object of the collection type that has been instantiated
+ # with +attributes+, linked to this object through a foreign key, and that has already
+ # been saved (if it passed the validation). *Note:* This only works if an associated
+ # object already exists, not if it's +nil+!
+ #
+ # (*Note*: +collection+ is replaced with the symbol passed as the first argument, so
+ # <tt>has_many :clients</tt> would add among others <tt>clients.empty?</tt>.)
#
- # Example: A Firm class declares <tt>has_many :clients</tt>, which will add:
+ # === Example
+ #
+ # A Firm class declares <tt>has_many :clients</tt>, which will add:
# * <tt>Firm#clients</tt> (similar to <tt>Clients.find :all, :conditions => "firm_id = #{id}"</tt>)
# * <tt>Firm#clients<<</tt>
# * <tt>Firm#clients.delete</tt>
@@ -647,52 +670,74 @@ module ClassMethods
# * <tt>Firm#clients.empty?</tt> (similar to <tt>firm.clients.size == 0</tt>)
# * <tt>Firm#clients.size</tt> (similar to <tt>Client.count "firm_id = #{id}"</tt>)
# * <tt>Firm#clients.find</tt> (similar to <tt>Client.find(id, :conditions => "firm_id = #{id}")</tt>)
+ # * <tt>Firm#clients.exist?(:name => 'ACME')</tt> (similar to <tt>Client.exist?(:name => 'ACME', :firm_id => firm.id)</tt>)
# * <tt>Firm#clients.build</tt> (similar to <tt>Client.new("firm_id" => id)</tt>)
# * <tt>Firm#clients.create</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save; c</tt>)
# The declaration can also include an options hash to specialize the behavior of the association.
#
- # Options are:
- # * <tt>:class_name</tt> - Specify the class name of the association. Use it only if that name can't be inferred
+ # === Supported options
+ # [:class_name]
+ # Specify the class name of the association. Use it only if that name can't be inferred
# from the association name. So <tt>has_many :products</tt> will by default be linked to the Product class, but
# if the real class name is SpecialProduct, you'll have to specify it with this option.
- # * <tt>:conditions</tt> - Specify the conditions that the associated objects must meet in order to be included as a +WHERE+
+ # [:conditions]
+ # Specify the conditions that the associated objects must meet in order to be included as a +WHERE+
# SQL fragment, such as <tt>price > 5 AND name LIKE 'B%'</tt>. Record creations from the association are scoped if a hash
# is used. <tt>has_many :posts, :conditions => {:published => true}</tt> will create published posts with <tt>@blog.posts.create</tt>
# or <tt>@blog.posts.build</tt>.
- # * <tt>:order</tt> - Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment,
+ # [:order]
+ # Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment,
# such as <tt>last_name, first_name DESC</tt>.
- # * <tt>:foreign_key</tt> - Specify the foreign key used for the association. By default this is guessed to be the name
+ # [:foreign_key]
+ # Specify the foreign key used for the association. By default this is guessed to be the name
# of this class in lower-case and "_id" suffixed. So a Person class that makes a +has_many+ association will use "person_id"
# as the default <tt>:foreign_key</tt>.
- # * <tt>:primary_key</tt> - Specify the method that returns the primary key used for the association. By default this is +id+.
- # * <tt>:dependent</tt> - If set to <tt>:destroy</tt> all the associated objects are destroyed
+ # [:primary_key]
+ # Specify the method that returns the primary key used for the association. By default this is +id+.
+ # [:dependent]
+ # If set to <tt>:destroy</tt> all the associated objects are destroyed
# alongside this object by calling their +destroy+ method. If set to <tt>:delete_all</tt> all associated
# objects are deleted *without* calling their +destroy+ method. If set to <tt>:nullify</tt> all associated
# objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. *Warning:* This option is ignored when also using
# the <tt>:through</tt> option.
- # * <tt>:finder_sql</tt> - Specify a complete SQL statement to fetch the association. This is a good way to go for complex
+ # [:finder_sql]
+ # Specify a complete SQL statement to fetch the association. This is a good way to go for complex
# associations that depend on multiple tables. Note: When this option is used, +find_in_collection+ is _not_ added.
- # * <tt>:counter_sql</tt> - Specify a complete SQL statement to fetch the size of the association. If <tt>:finder_sql</tt> is
+ # [:counter_sql]
+ # Specify a complete SQL statement to fetch the size of the association. If <tt>:finder_sql</tt> is
# specified but not <tt>:counter_sql</tt>, <tt>:counter_sql</tt> will be generated by replacing <tt>SELECT ... FROM</tt> with <tt>SELECT COUNT(*) FROM</tt>.
- # * <tt>:extend</tt> - Specify a named module for extending the proxy. See "Association extensions".
- # * <tt>:include</tt> - Specify second-order associations that should be eager loaded when the collection is loaded.
- # * <tt>:group</tt> - An attribute name by which the result should be grouped. Uses the <tt>GROUP BY</tt> SQL-clause.
- # * <tt>:limit</tt> - An integer determining the limit on the number of rows that should be returned.
- # * <tt>:offset</tt> - An integer determining the offset from where the rows should be fetched. So at 5, it would skip the first 4 rows.
- # * <tt>:select</tt> - By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if you, for example, want to do a join
+ # [:extend]
+ # Specify a named module for extending the proxy. See "Association extensions".
+ # [:include]
+ # Specify second-order associations that should be eager loaded when the collection is loaded.
+ # [:group]
+ # An attribute name by which the result should be grouped. Uses the <tt>GROUP BY</tt> SQL-clause.
+ # [:limit]
+ # An integer determining the limit on the number of rows that should be returned.
+ # [:offset]
+ # An integer determining the offset from where the rows should be fetched. So at 5, it would skip the first 4 rows.
+ # [:select]
+ # By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if you, for example, want to do a join
# but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will raise an error.
- # * <tt>:as</tt> - Specifies a polymorphic interface (See <tt>belongs_to</tt>).
- # * <tt>:through</tt> - Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt> and <tt>:foreign_key</tt>
+ # [:as]
+ # Specifies a polymorphic interface (See <tt>belongs_to</tt>).
+ # [:through]
+ # Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt> and <tt>:foreign_key</tt>
# are ignored, as the association uses the source reflection. You can only use a <tt>:through</tt> query through a <tt>belongs_to</tt>
# or <tt>has_many</tt> association on the join model.
- # * <tt>:source</tt> - Specifies the source association name used by <tt>has_many :through</tt> queries. Only use it if the name cannot be
+ # [:source]
+ # Specifies the source association name used by <tt>has_many :through</tt> queries. Only use it if the name cannot be
# inferred from the association. <tt>has_many :subscribers, :through => :subscriptions</tt> will look for either <tt>:subscribers</tt> or
# <tt>:subscriber</tt> on Subscription, unless a <tt>:source</tt> is given.
- # * <tt>:source_type</tt> - Specifies type of the source association used by <tt>has_many :through</tt> queries where the source
+ # [:source_type]
+ # Specifies type of the source association used by <tt>has_many :through</tt> queries where the source
# association is a polymorphic +belongs_to+.
- # * <tt>:uniq</tt> - If true, duplicates will be omitted from the collection. Useful in conjunction with <tt>:through</tt>.
- # * <tt>:readonly</tt> - If true, all the associated objects are readonly through the association.
- # * <tt>:validate</tt> - If false, don't validate the associated objects when saving the parent object. true by default.
+ # [:uniq]
+ # If true, duplicates will be omitted from the collection. Useful in conjunction with <tt>:through</tt>.
+ # [:readonly]
+ # If true, all the associated objects are readonly through the association.
+ # [:validate]
+ # If false, don't validate the associated objects when saving the parent object. true by default.
#
# Option examples:
# has_many :comments, :order => "posted_on"

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