Rails Dynamic Associations

Define your model associations in the database without changing the schema or models.

Use Adjustable Schema instead. It has a similar API, though it's not backward-compatible.

• Creates associations for your models when application starts.
• Provides Relation & Role models.
• No configuration code needed.
• No code generated or inserted to your app (except migrations).
• Adds some useful methods to ActiveRecord objects to handle their relations.

1. Add the gem to your Gemfile and bundle it.
2. Copy migrations to your app (rake rails_dynamic_associations:install:migrations).
3. Migrate the DB (rake db:migrate).

Add configuration records to the DB:

	Relation.create({
		source_type: Person,
		target_type: Book,
	})

Or use a helper method:

	Relation.seed Person, Book

Now you have:

	person.books
	book.people

You can create multiple role-based associations between two models.

	Relation.seed Person, Book, %w[
		author
		editor
	]

You will get:

	person.books
	person.authored_books
	person.edited_books

	book.people
	book.author_people
	book.editor_people

In case you have set up relations with a User model you'll get a slightly different naming:

	Relation.seed User, Book, %w[
		author
		editor
	]

	book.users
	book.authors
	book.editors

The list of models to be handled this way can be set with actor_model_names configuration parameter. It includes User by default.

• Describe self-referential associations.

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request