Rails admin tables with read only access

Question

I am using rails server with rails_admin

I want to add a table to my include_models but I don't want to let write access to one/few of the models:

My admin looks like this:

# frozen_string_literal: true

RailsAdmin.config do |config|
  ### Popular gems integration

  # == Devise ==
  config.authenticate_with do
    warden.authenticate! scope: :user
  end
  config.actions do
    dashboard                     # mandatory
    index                         # mandatory
    new
    export
    bulk_delete
    show
    edit
    delete
    show_in_app

  end

  config.included_models = %w[ MyModel1
                               MyModel2]
end

I would like to add something like

config.read_only_models =  %w[MyModel3, MyModel4]

Any suggestion?

Answer 1

I've divided my answer to 2 sections as it may apply to different scenarios:

General case:
General behaviour can be set by adding a readonly? method for the model(s).
If the value is set to true , attempting to update a record will result in an error.
See here for more details.

def readonly?
  true
end

ActiveRecord's underlying persistence will check readonly? before creating or updating any records.
You can also add dynamic content inspection such as:

def readonly?
  read_only_list.include? (self.class.name)
end

RailsAdmin specific behaviour (2nd scenario):
If you want to set a specific behaviour for RailsAdmin, you can create a special role and then use CanCanCan which is an authorization library which restricts what resources a given user is allowed to access.
It can also restrict RailsAdmin & grant access using an Ability class which defines different permissions depending upon the user's role.
See an example how to Use different Ability classes for front-end and admin

Answer 2

You need to do it on the rails admin model configuration to have access to the current user. I'm afraid this rules out doing it at the RailsAdmin.config level.

You'll need to do it then field by field.

class MyModel3 < ApplicationRecord

  rails_admin do
    configure :field do
      read_only do
        bindings[:view].current_user.admin?
      end
    end

    configure :field2 do
      read_only do
        bindings[:view].current_user.admin?
      end
    end

    configure :field3 do
      read_only do
        bindings[:view].current_user.admin?
      end
    end
    # ...
  end
end

Not ideal but you'll see that is impossible with the current implementation of the actions by taking a look at the code of the edit action that inherits from base .