Trying to rename Devise Model name in ruby on rails

Question

We had 2 ruby on rails apps that one was using json outputs from the other. But we decided to integrate them which ran into a lot of issues.

The issue now is, the writer of one system used to 'devise' gem for all user authentication and registration, which was fine. But when we had to integrate them it caused problems, because the other system also had a model named users, which was not used for this purpose.

And it would be A LOT easier to just rename the devise user model to something like "site-user" which im currently trying. Than re-name the other model.

I tried renaming everything that relates to devise in all the files to siteuser instead of user but still getting errors. Anyone have any advice on this. If i can just get this devise user to use a different model name than "User" i will be able to make a lot of progress but this is proving quite the annoyance.

Current error is

NoMethodError in Devise::Sessions#new - highlighting the line with "if user_signed_in"

    <li>
    <%= link_to t('nav.support'), 'http://banana.sweatervest.net/' %>
    </li>
    <%- if user_signed_in? -%>
    <%- if controller_name != 'dashboard' -%>
    <li>
    <%= link_to t('nav.dashboard'), :dashboard %>

Answer 1

Why not uninstall it and then reinstall the model.

First:

 rails destroy devise User

then:

rails generate devise whateveryourmodelnamehere

Much easier than trying to rename everything, only because I've been there ;)

Answer 2

I actually took the long route (? 1 hour work) to rename my Devise model I had named Admin some decade ago. I wanted it to be User.

Note that you might have got yourself wrapped a lot more into the naming than I did so buyers of this solution beware! For instance I had not indexes on any of my tables (which I will do now for goodness sake). Devise itself doesn't really write the model name into stuff so it's mostly digging into your own past. My step by step that worked for me:

I - start a new clean git branch. You will suffer unless you are able to oversee what you are doing next.

II - Renaming all cases of admin -> user. (~34 files affected) Using search/replace (case sensitive) in my editor:

1. lowcases of admin -> user (also look for admins -> users that got missed)
2. uppercase Admin -> User

Manually rename some files like the model: admin.rb -> user.rb

III - Create some migrations to create new users table and change admin_id to user_id in those tables affected:

• Take the create_table body from schema.rb and wrap that into a migration, using the new name of the devise model, mine ended up like:

    class AddUsersTable < ActiveRecord::Migration[5.2]
      def change
        create_table :users do |t|
          t.string "email", limit: 255, default: "", null: false
          t.string "encrypted_password", limit: 255, default: "", null: false
          t.string "reset_password_token", limit: 255
          t.datetime "reset_password_sent_at"
          t.datetime "remember_created_at"
          t.integer "sign_in_count", default: 0, null: false
          t.datetime "current_sign_in_at"
          t.datetime "last_sign_in_at"
          t.string "current_sign_in_ip", limit: 255
          t.string "last_sign_in_ip", limit: 255
          t.datetime "created_at"
          t.datetime "updated_at"
          t.index ["email"], name: "index_users_on_email", unique: true
          t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true  
        end
      end
    end

And next a migration to change what other tables need to update the foregin key

class RenameAdminIdsToUser < ActiveRecord::Migration[5.2]
  def change
    rename_column(:batches, :admin_id, :user_id)
    rename_column(:offices, :admin_id, :user_id)
  end
end

IV - copy data from old table to the new. In my case I'm using postgres, but the SQL will probably work with most SQL-based DBs. Here I logged into my postgres-db and run the following sql:

INSERT INTO users (SELECT * FROM admins);

(This query can also be put in a migration which is a bit cleaner.)

V - if you are setting up a new rails like me - going from rails 5 to 7, also make sure to copy settings from devise.rb, like pepper token keys to match the data you have in your old table.

After these steps my rails app was moving on with User instead of Admin as if nothing happened!