Godmin a cool admin option for rails

When we develop applications sometimes we need to handle the administration of some common resources, doing some repetitive tasks like paginations, filtering, batch actions, and others.

Create this for own hand its hard most part of the time, so we can use some admin gems or engines, there is a lot of these in the rails ecosystem, like administrate, rails-admin, etc.

But today I'll show you an interesting engine called Godmin, I discover godmin when I was working at able.co, I like the way this tool works and makes things easier.

Godmin in the best option vs others admins/engines, because it is pretty lightweight, it does not have a DSL, you can override pretty much anything. On the other hand, rails_admin (and several others) are really bloated with stuff you may not actually need and that gets tricky to override/extend.

This was the answer from my old tech lead and the first person who built the setup of the project in which I worked for a year and a half.

So given that context, we are going to set up a godmin as an engine in a new Rails 6 project, so lets started :)

1. Create a new project

You need to create a new rails project:

rails new super-admin  -T -d postgresql

The flag -T is to skip the installation of minitest and -d postgresql because I like to use PostgreSQL as my default database.

2. Create some resources

Let's create users, categories, and articles crud with scaffold

rails g scaffold Author first_name last_date birthday:date
rails g scaffold Genre name
rails g scaffold Book name description author:references genre:references

Then we need to create the database and run the migrations:

rails db:create
rails db:migrate

Now, we have a user, category, and articles crud.

3. Install mountable engine

At this point we have an application working, so it's time to install godmin as a mountable engine:

bin/rails plugin new admin_dashboard --mountable

I prefer called admin_dashboard to avoid future problems if we will have an Admin model(this tends to happen a lot)

• Note: it's very important to use _ and not -.

Now, we need to add our mountable admin-dashboard to our routes:

Rails.application.routes.draw do
  resources :articles
  resources :categories
  resources :users

  mount AdminDashboard::Engine, at: "admin"
end

4. Add godmin gem to engine

We are going to add godmin as a dependency on admin-dashboard/admin-dashboard.gemspec, also you should remove sqlite3 if it is there.

  ...
  # remove `TODO:` and change homepage
  spec.homepage    = "http://condef5.com"
  spec.summary     = "Summary of Admin::Dashboard."
  spec.description = "Description of Admin::Dashboard."

  ...

  spec.add_dependency "rails", "~> 6.0.3", ">= 6.0.3.4"
  spec.add_dependency "godmin", "~> 2.0.0"

Then we just need to install godmin gem:

bundle install

5. Install godmin

Now, we install godmin with this command:

admin_dashboard/bin/rails generate godmin:install

Since godmin was installed as an engine, we need import godmin in admin_dashboard/lib/admin_dashboard.rb

require "admin_dashboard/engine"
require "godmin"

module AdminDashboard
end

6. Fix AssetNotPrecompiled

We almost ready, if we run the server:

rails server

And if we go to the admin, we can see an error with the assets

We can fix this by precompiling the missing assets:

# config/initializers/assets.rb
Rails.application.config.assets.precompile += %w(admin_dashboard/application.css admin_dashboard/application.js)

We create the javascript missing file:

touch admin_dashboard/app/assets/javascript/admin_dashboard/application.js

And precompile the assets:

rake assets:precompile

And if we run the server, we can see our admin without errors, but one more thing we need to import the CSS styles form godmin: Godmin also has a defined style, so we can incorporate:

# stylesheets/admin_dashboard/application.css
...
 *= require godmin
 *= require_tree .
 *= require_self

7. Add resources to godmin

This the easy part from now to the future

To generate the author crud we just have to run this command:

 admin_dashboard/bin/rails generate godmin:resource author first_name last_name birthday

The same with genres:

 admin_dashboard/bin/rails generate godmin:resource genre name

And finally with books:

admin_dashboard/bin/rails g godmin:resource books  name description  author genre

Note: if you have some errors, you just need to restart the server.

8 Fixing some small details

After created some authors and genres, you maybe have realized at the time to create articles, see this selects:

We can fix this, added to the Author and Genre model a to_s method

# app/models/author.rb
class Author < ApplicationRecord
  def to_s
    "#{first_name} #{last_name}"
  end
end

# app/models/genre.rb
class Genre < ApplicationRecord
  def to_s
    name
  end
end

And the result should be this:

Another improvement we can make is when creating an author, we could have a form view like this:

For this, we just need to require some javascript files in admin_dashboard/app/assets/javascript/admin_dashboard/application.js:

//= require jquery
//= require moment
//= require godmin
//= require_tree .

You can find all steps in this pull request

Conclusion

Yeah definitely this was a little tricky to install, in the previous versions the process was more straightforward, but with rails 6, the complexity has a little complex, but believe me this tool is worth it, it has many interesting things, you can learn how to add filters, scopes pagination and more in its repository :)

And before I go maybe you are wondering what about the styles: bootstrap, really?, don't worry about this, in the next post I'll show you how to integrate godmin with modern CSS frameworks.