Delegate Association#options to the reflection, and replace 'reflection.options' with 'options'. Also add through_options and source_options methods for through associations.

Associations - where possible, call attributes methods rather than directly accessing the instance variables

Split AssociationProxy into an Association class (and subclasses) which manages the association, and a CollectionProxy class which is *only* a proxy. Singular associations no longer have a proxy. See CHANGELOG for more.

Allow building and then later saving has_many :through records, such that the join record is automatically saved too. This requires the :inverse_of option to be set on the source association in the join model. See the CHANGELOG for details. [#4329 state:resolved]

Add a transaction wrapper in add_to_target. This means that #build will now also use a transaction. IMO this is reasonable given that the before_add and after_add callbacks might do anything, and this great consistency allows us to abstract out the duplicate code from #build and #create.

Add interpolation of association conditions back in, in the form of proc { ... } rather than instance_eval-ing strings

[#6423 state:committed]
Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

Refactor the implementations of AssociatioCollection#delete and #destroy to be more consistent with each other, and to stop passing blocks around, thus making the execution easier to follow.

Correctly update counter caches on deletion for has_many :through [#2824 state:resolved]. Also fixed a bunch of other counter cache bugs in the process, as once I fixed this one others started appearing like nobody's business.

Support the :dependent option on has_many :through associations. For historical and practical reasons, :delete_all is the default deletion strategy employed by association.delete(*records), despite the fact that the default strategy is :nullify for regular has_many. Also, this only works at all if the source reflection is a belongs_to. For other situations, you should directly modify the through association.

Make record.association.destroy(*records) on habtm and hm:t only delete records in the join table. This is to make the destroy method more consistent across the different types of associations. For more details see the CHANGELOG entry.

Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

Has many through - It is not necessary to manually merge in the conditions hash for the through record, because the creation is done directly on the through association, which will already handle setting the conditions.

AssociationCollection#to_ary should definitely dup the target! Also changed #replace which was previously incorrect, but the test passed due to the fact that to_a was not duping.