Displaying Read-Only Attribute

[firewalker06]

Since madmin works by iterating through model.attributes, I was thinking using ActiveModel::Attributes::ClassMethods#attribute would work if we want to have a Read-Only attribute in madmin. Turns out its true:

# models/invoice.rb
class Invoice < ApplicationRecord
  attribute :total

  def total
    # do some calculations
  end
end

# madmin/resources/invoice_resource.rb
class InvoiceResource < Madmin::Resource
  attribute :total, form: false # mocking as read-only
end

But I think it would be good idea to have read_attribute that displays in Index and Show view.

[firewalker06]

Or a read_only: true option in madmin's attribute class method.

[excid3]

We could probably check for attr_readonly and default form: false for those.

class Post < ActiveRecord::Base
  attr_readonly :title
end

post = Post.create!(title: "Introducing Ruby on Rails!")
post.update(title: "a different title") # change to title will be ignored

https://api.rubyonrails.org/classes/ActiveRecord/ReadonlyAttributes/ClassMethods.html