Formatting, grammar and spelling fixes for the associations documenta…

…tion. [seanhussey] Closes #8899

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7368 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/lib/active_record/aggregations.rb

@@ -70,7 +70,7 @@ def clear_aggregation_cache #:nodoc:
     #  end
     #  
     # Now it's possible to access attributes from the database through the value objects instead. If you choose to name the
-    # composition the same as the attributes name, it will be the only way to access that attribute. That's the case with our
+    # composition the same as the attribute's name, it will be the only way to access that attribute. That's the case with our
     # +balance+ attribute. You interact with the value objects just like you would any other attribute, though:
     #
     #   customer.balance = Money.new(20)     # sets the Money value object and the attribute
@@ -92,19 +92,19 @@ def clear_aggregation_cache #:nodoc:
     #
     # == Writing value objects
     #
-    # Value objects are immutable and interchangeable objects that represent a given value, such as a Money object representing
-    # $5. Two Money objects both representing $5 should be equal (through methods such as == and <=> from Comparable if ranking
-    # makes sense). This is unlike entity objects where equality is determined by identity. An entity class such as Customer can
+    # Value objects are immutable and interchangeable objects that represent a given value, such as a +Money+ object representing
+    # $5. Two +Money+ objects both representing $5 should be equal (through methods such as == and <=> from +Comparable+ if ranking
+    # makes sense). This is unlike entity objects where equality is determined by identity. An entity class such as +Customer+ can
     # easily have two different objects that both have an address on Hyancintvej. Entity identity is determined by object or
-    # relational unique identifiers (such as primary keys). Normal ActiveRecord::Base classes are entity objects.
+    # relational unique identifiers (such as primary keys). Normal <tt>ActiveRecord::Base</tt> classes are entity objects.
     #
-    # It's also important to treat the value objects as immutable. Don't allow the Money object to have its amount changed after
-    # creation. Create a new money object with the new value instead. This is exemplified by the Money#exchanged_to method that
+    # It's also important to treat the value objects as immutable. Don't allow the +Money+ object to have its amount changed after
+    # creation. Create a new +Money+ object with the new value instead. This is exemplified by the <tt>Money#exchanged_to</tt> method that
     # returns a new value object instead of changing its own values. Active Record won't persist value objects that have been
-    # changed through other means than the writer method.
+    # changed through means other than the writer method.
     #
     # The immutable requirement is enforced by Active Record by freezing any object assigned as a value object. Attempting to 
-    # change it afterwards will result in a TypeError.
+    # change it afterwards will result in a <tt>TypeError</tt>.
     # 
     # Read more about value objects on http://c2.com/cgi/wiki?ValueObject and on the dangers of not keeping value objects
     # immutable on http://c2.com/cgi/wiki?ValueObjectsShouldBeImmutable
@@ -119,8 +119,8 @@ module ClassMethods
       # * <tt>:mapping</tt> - specifies a number of mapping arrays (attribute, parameter) that bind an attribute name
       #   to a constructor parameter on the value class.
       # * <tt>:allow_nil</tt> - specifies that the aggregate object will not be instantiated when all mapped
-      #   attributes are nil.  Setting the aggregate class to nil has the effect of writing nil to all mapped attributes.
-      #   This defaults to false.
+      #   attributes are +nil+.  Setting the aggregate class to +nil+ has the effect of writing +nil+ to all mapped attributes.
+      #   This defaults to +false+.
       #
       # Option examples:
       #   composed_of :temperature, :mapping => %w(reading celsius)

activerecord/lib/active_record/associations/association_collection.rb

@@ -65,7 +65,7 @@ def delete(*records)
 
       # Removes all records from this association.  Returns +self+ so method calls may be chained.
       def clear
-        return self if length.zero? # forces load_target if hasn't happened already
+        return self if length.zero? # forces load_target if it hasn't happened already
 
         if @reflection.options[:dependent] && @reflection.options[:dependent] == :delete_all
           destroy_all

activerecord/lib/active_record/associations/association_proxy.rb

@@ -139,7 +139,7 @@ def load_target
         end
 
         # Can be overwritten by associations that might have the foreign key available for an association without
-        # having the object itself (and still being a new record). Currently, only belongs_to present this scenario.
+        # having the object itself (and still being a new record). Currently, only belongs_to presents this scenario.
         def foreign_key_present
           false
         end

activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb

@@ -14,7 +14,7 @@ def build(attributes = {})
       end
 
       def create(attributes = {})
-        # Can't use Base.create since the foreign key may be a protected attribute.
+        # Can't use Base.create because the foreign key may be a protected attribute.
         if attributes.is_a?(Array)
           attributes.collect { |attr| create(attr) }
         else
@@ -138,8 +138,8 @@ def construct_scope
         end
 
         # Join tables with additional columns on top of the two foreign keys must be considered ambigious unless a select
-        # clause has been explicitly defined. Otherwise you can get broken records back, if, say, the join column also has
-        # and id column, which will then overwrite the id column of the records coming back.
+        # clause has been explicitly defined. Otherwise you can get broken records back, if, for example, the join column also has
+        # an id column. This will then overwrite the id column of the records coming back.
         def finding_with_ambigious_select?(select_clause)
           !select_clause && @owner.connection.columns(@reflection.options[:join_table], "Join Table Columns").size != 2
         end

activerecord/lib/active_record/associations/has_many_through_association.rb

@@ -67,7 +67,7 @@ def <<(*records)
 
       [:push, :concat].each { |method| alias_method method, :<< }
 
-      # Remove +records+ from this association.  Does not destroy +records+.
+      # Removes +records+ from this association.  Does not destroy +records+.
       def delete(*records)
         records = flatten_deeper(records)
         records.each { |associate| raise_on_type_mismatch(associate) }

activerecord/lib/active_record/associations/has_one_association.rb

@@ -76,7 +76,7 @@ def construct_scope
         end
 
         def new_record(replace_existing)
-          # make sure we load the target first, if we plan on replacing the existing
+          # Make sure we load the target first, if we plan on replacing the existing
           # instance. Otherwise, if the target has not previously been loaded
           # elsewhere, the instance we create will get orphaned.
           load_target if replace_existing

activerecord/lib/active_record/callbacks.rb

@@ -1,25 +1,25 @@
 require 'observer'
 
 module ActiveRecord
-  # Callbacks are hooks into the lifecycle of an Active Record object that allows you to trigger logic
+  # Callbacks are hooks into the lifecycle of an Active Record object that allow you to trigger logic
   # before or after an alteration of the object state. This can be used to make sure that associated and
-  # dependent objects are deleted when destroy is called (by overwriting before_destroy) or to massage attributes
-  # before they're validated (by overwriting before_validation). As an example of the callbacks initiated, consider
-  # the Base#save call:
-  #
-  # * (-) save
-  # * (-) valid?
-  # * (1) before_validation
-  # * (2) before_validation_on_create
-  # * (-) validate
-  # * (-) validate_on_create
-  # * (3) after_validation
-  # * (4) after_validation_on_create
-  # * (5) before_save
-  # * (6) before_create
-  # * (-) create
-  # * (7) after_create
-  # * (8) after_save
+  # dependent objects are deleted when destroy is called (by overwriting +before_destroy+) or to massage attributes
+  # before they're validated (by overwriting +before_validation+). As an example of the callbacks initiated, consider
+  # the <tt>Base#save</tt> call:
+  #
+  # * (-) <tt>save</tt>
+  # * (-) <tt>valid</tt>
+  # * (1) <tt>before_validation</tt>
+  # * (2) <tt>before_validation_on_create</tt>
+  # * (-) <tt>validate</tt>
+  # * (-) <tt>validate_on_create</tt>
+  # * (3) <tt>after_validation</tt>
+  # * (4) <tt>after_validation_on_create</tt>
+  # * (5) <tt>before_save</tt>
+  # * (6) <tt>before_create</tt>
+  # * (-) <tt>create</tt>
+  # * (7) <tt>after_create</tt>
+  # * (8) <tt>after_save</tt>
   #
   # That's a total of eight callbacks, which gives you immense power to react and prepare for each state in the
   # Active Record lifecycle.
@@ -62,8 +62,8 @@ module ActiveRecord
   #     before_destroy :destroy_readers
   #   end
   #
-  # Now, when Topic#destroy is run only +destroy_author+ is called. When Reply#destroy is run both +destroy_author+ and
-  # +destroy_readers+ is called. Contrast this to the situation where we've implemented the save behavior through overwriteable
+  # Now, when <tt>Topic#destroy</tt> is run only +destroy_author+ is called. When <tt>Reply#destroy</tt> is run, both +destroy_author+ and
+  # +destroy_readers+ are called. Contrast this to the situation where we've implemented the save behavior through overwriteable
   # methods:
   #
   #   class Topic < ActiveRecord::Base
@@ -74,9 +74,9 @@ module ActiveRecord
   #     def before_destroy() destroy_readers end
   #   end
   #
-  # In that case, Reply#destroy would only run +destroy_readers+ and _not_ +destroy_author+. So use the callback macros when
-  # you want to ensure that a certain callback is called for the entire hierarchy and the regular overwriteable methods when you
-  # want to leave it up to each descendent to decide whether they want to call +super+ and trigger the inherited callbacks.
+  # In that case, <tt>Reply#destroy</tt> would only run +destroy_readers+ and _not_ +destroy_author+. So, use the callback macros when
+  # you want to ensure that a certain callback is called for the entire hierarchy, and use the regular overwriteable methods
+  # when you want to leave it up to each descendent to decide whether they want to call +super+ and trigger the inherited callbacks.
   #
   # *IMPORTANT:* In order for inheritance to work for the callback queues, you must specify the callbacks before specifying the
   # associations. Otherwise, you might trigger the loading of a child before the parent has registered the callbacks and they won't
@@ -143,31 +143,31 @@ module ActiveRecord
   #     before_destroy 'self.class.delete_all "parent_id = #{id}"'
   #   end
   #
-  # Notice that single plings (') are used so the #{id} part isn't evaluated until the callback is triggered. Also note that these
+  # Notice that single plings (') are used so the <tt>#{id}</tt> part isn't evaluated until the callback is triggered. Also note that these
   # inline callbacks can be stacked just like the regular ones:
   #
   #   class Topic < ActiveRecord::Base
   #     before_destroy 'self.class.delete_all "parent_id = #{id}"',
   #                    'puts "Evaluated after parents are destroyed"'
   #   end
   #
-  # == The after_find and after_initialize exceptions
+  # == The +after_find+ and +after_initialize+ exceptions
   #
-  # Because after_find and after_initialize are called for each object found and instantiated by a finder, such as Base.find(:all), we've had
-  # to implement a simple performance constraint (50% more speed on a simple test case). Unlike all the other callbacks, after_find and
-  # after_initialize will only be run if an explicit implementation is defined (<tt>def after_find</tt>). In that case, all of the
+  # Because +after_find+ and +after_initialize+ are called for each object found and instantiated by a finder, such as <tt>Base.find(:all)</tt>, we've had
+  # to implement a simple performance constraint (50% more speed on a simple test case). Unlike all the other callbacks, +after_find+ and
+  # +after_initialize+ will only be run if an explicit implementation is defined (<tt>def after_find</tt>). In that case, all of the
   # callback types will be called.
   #
-  # == before_validation* returning statements
+  # == <tt>before_validation*</tt> returning statements
   #
-  # If the returning value of a before_validation callback can be evaluated to false, the process will be aborted and Base#save will return false.
-  # If Base#save! is called it will raise a RecordNotSave error.
+  # If the returning value of a +before_validation+ callback can be evaluated to +false+, the process will be aborted and <tt>Base#save</tt> will return +false+.
+  # If <tt>Base#save!</tt> is called it will raise a +RecordNotSave+ exception.
   # Nothing will be appended to the errors object.
   #
   # == Cancelling callbacks
   #
-  # If a before_* callback returns false, all the later callbacks and the associated action are cancelled. If an after_* callback returns
-  # false, all the later callbacks are cancelled. Callbacks are generally run in the order they are defined, with the exception of callbacks
+  # If a <tt>before_*</tt> callback returns +false+, all the later callbacks and the associated action are cancelled. If an <tt>after_*</tt> callback returns
+  # +false+, all the later callbacks are cancelled. Callbacks are generally run in the order they are defined, with the exception of callbacks
   # defined as methods on the model, which are called last.
   module Callbacks
     CALLBACKS = %w(
@@ -215,10 +215,10 @@ def instantiate_with_callbacks(record)
       end
     end
 
-    # Is called when the object was instantiated by one of the finders, like Base.find.
+    # Is called when the object was instantiated by one of the finders, like <tt>Base.find</tt>.
     #def after_find() end
 
-    # Is called after the object has been instantiated by a call to Base.new.
+    # Is called after the object has been instantiated by a call to <tt>Base.new</tt>.
     #def after_initialize() end
 
     def initialize_with_callbacks(attributes = nil) #:nodoc:
@@ -229,10 +229,10 @@ def initialize_with_callbacks(attributes = nil) #:nodoc:
     end
     private :initialize_with_callbacks
 
-    # Is called _before_ Base.save (regardless of whether it's a create or update save).
+    # Is called _before_ <tt>Base.save</tt> (regardless of whether it's a +create+ or +update+ save).
     def before_save() end
 
-    # Is called _after_ Base.save (regardless of whether it's a create or update save).
+    # Is called _after_ <tt>Base.save</tt> (regardless of whether it's a +create+ or +update+ save).
     #
     #  class Contact < ActiveRecord::Base
     #    after_save { logger.info( 'New contact saved!' ) }
@@ -246,10 +246,10 @@ def create_or_update_with_callbacks #:nodoc:
     end
     private :create_or_update_with_callbacks
 
-    # Is called _before_ Base.save on new objects that haven't been saved yet (no record exists).
+    # Is called _before_ <tt>Base.save</tt> on new objects that haven't been saved yet (no record exists).
     def before_create() end
 
-    # Is called _after_ Base.save on new objects that haven't been saved yet (no record exists).
+    # Is called _after_ <tt>Base.save</tt> on new objects that haven't been saved yet (no record exists).
     def after_create() end
     def create_with_callbacks #:nodoc:
       return false if callback(:before_create) == false
@@ -259,10 +259,10 @@ def create_with_callbacks #:nodoc:
     end
     private :create_with_callbacks
 
-    # Is called _before_ Base.save on existing objects that have a record.
+    # Is called _before_ <tt>Base.save</tt> on existing objects that have a record.
     def before_update() end
 
-    # Is called _after_ Base.save on existing objects that have a record.
+    # Is called _after_ <tt>Base.save</tt> on existing objects that have a record.
     def after_update() end
 
     def update_with_callbacks #:nodoc:
@@ -273,25 +273,25 @@ def update_with_callbacks #:nodoc:
     end
     private :update_with_callbacks
 
-    # Is called _before_ Validations.validate (which is part of the Base.save call).
+    # Is called _before_ <tt>Validations.validate</tt> (which is part of the <tt>Base.save</tt> call).
     def before_validation() end
 
-    # Is called _after_ Validations.validate (which is part of the Base.save call).
+    # Is called _after_ <tt>Validations.validate</tt> (which is part of the <tt>Base.save</tt> call).
     def after_validation() end
 
-    # Is called _before_ Validations.validate (which is part of the Base.save call) on new objects
+    # Is called _before_ <tt>Validations.validate</tt> (which is part of the <tt>Base.save</tt> call) on new objects
     # that haven't been saved yet (no record exists).
     def before_validation_on_create() end
 
-    # Is called _after_ Validations.validate (which is part of the Base.save call) on new objects
+    # Is called _after_ <tt>Validations.validate</tt> (which is part of the <tt>Base.save</tt> call) on new objects
     # that haven't been saved yet (no record exists).
     def after_validation_on_create()  end
 
-    # Is called _before_ Validations.validate (which is part of the Base.save call) on
+    # Is called _before_ <tt>Validations.validate</tt> (which is part of the <tt>Base.save</tt> call) on
     # existing objects that have a record.
     def before_validation_on_update() end
 
-    # Is called _after_ Validations.validate (which is part of the Base.save call) on
+    # Is called _after_ <tt>Validations.validate</tt> (which is part of the <tt>Base.save</tt> call) on
     # existing objects that have a record.
     def after_validation_on_update()  end
 
@@ -308,13 +308,13 @@ def valid_with_callbacks? #:nodoc:
       return result
     end
 
-    # Is called _before_ Base.destroy.
+    # Is called _before_ <tt>Base.destroy</tt>.
     #
     # Note: If you need to _destroy_ or _nullify_ associated records first,
-    # use the _:dependent_ option on your associations.
+    # use the <tt>:dependent</tt> option on your associations.
     def before_destroy() end
 
-    # Is called _after_ Base.destroy (and all the attributes have been frozen).
+    # Is called _after_ <tt>Base.destroy</tt> (and all the attributes have been frozen).
     #
     #  class Contact < ActiveRecord::Base
     #    after_destroy { |record| logger.info( "Contact #{record.id} was destroyed." ) }