Rails 6 adds ActiveModel::Errors#of_kind?

Amit Choudhary

By Amit Choudhary

on April 1, 2019

This blog is part of our  Rails 6 series.

Rails 6 added of_kind? on ActiveModel::Errors. It returns true if the ActiveModel::Errors object has provided a key and message associated with it. The default message is :invalid.

of_kind? is same as ActiveModel::Errors#added? but, it doesn't take extra options as a parameter.

Let's checkout how it works.

Rails 6.0.0.beta2

1>> class User < ApplicationRecord
2>>   validates :name, presence: true
3>> end
4
5>> user = User.new
6
7=> => #<User id: nil, name: nil, password: nil, created_at: nil, updated_at: nil>
8
9>> user.valid?
10
11=> false
12
13>> user.errors
14
15=> #<ActiveModel::Errors:0x00007fc462a1d140 @base=#<User id: nil, name: nil, password: nil, created_at: nil, updated_at: nil>, @messages={:name=>["can't be blank"]}, @details={:name=>[{:error=>:blank}]}>
16
17>> user.errors.of_kind?(:name)
18
19=> false
20
21>> user.errors.of_kind?(:name, :blank)
22
23=> true
24
25>> user.errors.of_kind?(:name, "can't be blank")
26
27=> true
28
29>> user.errors.of_kind?(:name, "is blank")
30
31=> false

Here is the relevant pull request.

If this blog was helpful, check out our full blog archive.

Stay up to date with our blogs.

Subscribe to receive email notifications for new blog posts.