Rails 6 has made
many new additions to Array and Enumerable:
- Array#including
- Array#excluding
- Enumerable#including
- Enumerable#excluding
Array#excluding and Enumerable#excluding
There are times when we would like to remove an element from a collection.
On Array or Enumerable, we could achieve this by collectionA - collectionB.
Rails offers a more readable approach to these via Array#without and Enumerable#without
# current_user is set to currently logged in user
all_active_users = User.where(status: "active")
all_active_users.without(current_user)
# This returns all active users excluding
# the currently logged in user
# More simpler examples
[ 1, 2, 3, 4, 5 ].without(4)
#=> [1, 2, 3, 5]
# Without also takes multiple arguments to be removed
[ 1, 2, 3, 4, 5 ].without(4, 5)
#=> [1, 2, 3] With the introduction of its counterparts #including,
we can now perform this same functionality as #excluding
[ 1, 2, 3, 4, 5 ].excluding(4)
#=> [1, 2, 3, 5]
[ 1, 2, 3, 4, 5 ].excluding(4, 5)
#=> [1, 2, 3] With this addition, it also fixes an issue
where the exclusion would fail if we passed an Array.
We can also successfully pass collections to be excluded now.
# Before
[ 1, 2, 3, 4, 5 ].excluding([4, 5])
#=> [1, 2, 3, 4, 5]
# After
[ 1, 2, 3, 4, 5 ].excluding([4, 5])
#=> [1, 2, 3]
# Exclude collections
all_active_users = User.where(status: "active")
high_risk_users = User.where(risk: true)
all_active_users.excluding(high_risk_users)
# => User collection with active users who are not high risk The without method is still available and is an alias to excluding.
Array#including and Enumerable#including
To match their counterparts #excluding we can now
perform #including on Array and Enumerable.
This is a shorthand and more readable form of
addition of two collections.
[ 1, 2, 3 ].including([4, 5])
# => [1, 2, 3, 4, 5]
# Accepts and handles passed Arrays
%w{Ruby Pearl}.including(%w{Java})
# => ["Ruby", "Pearl", "Java"]
# We can also include on collections
all_active_users = User.where(status: "active")
low_risk_users = User.where(risk: false)
all_active_users.including(low_risk_users)
# => User collection with active users as well as who are not high riskAs we can see, #including and #excluding add an easier and more readable way to
work with collection addition and removals.
