CanCanCan 3.2.0

Hi all 👋,
a new version of CanCanCan is out!

Again, we have a minor release but it includes a bunch of very important features, next to support for Rails 6.1.0.

I have opened a sponsorship program, please consider supporting the project if you use CanCanCan. It really helps!

Switching query strategy

Since version 3.0.0 we started changing the way we perform the queries when using accessible_by, in order to be more performant and reliable.

As expected, this new way of performing the queries didn't fit everyone, so in version 3.1.0 we switched from left_joins to subqueries (see relevant PR).

This again didn't make everyone happy 😃 , so we decided, in the version 3.2.0 to allow to configure the preferred query mechanism: left joins or inner queries.

You can now setup:

CanCan.accessible_by_strategy = :subquery # or :left_join

to change it.

Support for Single Table Inheritance

Single Table Inheritance is now supported. Given the following:

class Vehicle < ApplicationRecord

class Car < Vehicle

class Motorbike < Vehicle

You can play with rules by defining:

can :read, Vehicle

and query for:

Vehicle.accessible_by
# or
Motorbike.accessible_by

Here is an example:

can :read, Motorbike

Vehicle.accessible_by(...) # => returns only motorbikes

Check the relevant PR for more examples and note that there are currently some minor issues

Support for associations in rules definition

When using associations in rules definition you always had to use column names. Now, thanks to this PR you can also use the association name.

# previously you had to define:
can :edit, Book, author_id: user.id

# now you can also write:
can :edit, Book, author: user

Enjoy! And to the next one...