The Contacts Module: Set Up

9.1. What is the Contacts module?

In most CRMs, you will find a way to manage contacts. This is where users can fill in information about their clients, leads, and so on. BlastCRM will follow the same principle, and we will give users a way to manage their contacts. We will also extend the dashboard to add a summary of a user’s last contacts.

In this new module, we will implement the following:

• Contact CRUD (models/controllers/views)

  We’re going to add the basic views to create, edit and delete contacts. Users will be able to manage their contacts with these views. Initially, we will simply list all the contacts.

• A “Contacts” link in the main navigation bar

  We want to be able to easily access the list of contacts from the menu, and that means hooking up in the navigation we built in the Core module.

• Users and Contacts relationship

  Linking the User model with the Contact model will give us the option to show only the relevant contacts for each user.

• Contact overview on the dashboard

  The dashboard is currently empty. We’re going to extend it, and add a list of the last contacts.

9.2. Generating the Contacts engine

In the previous chapter we had to do a lot of folder-rearranging, which was quite boring. You’ll be happy to know that there is a better way to generate a modular engine the way it should look, but for the first chapter we wanted you to have a deeper understanding of how and why we organized the engine like we did, so we went through all the annoying steps. Now, we’re about to generate a new engine, a feature module, which will get plugged in on a Core type engine.

To do this, Thibault wrote a small and simple gem that we can use, called modular_engine. Let’s see how it works, but first, let’s checkout a branch for this chapter:

git checkout -b Chapter-9

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gem 'modular_engine', '~> 0.9.5'
gem 'deface', '~> 1.4.0'

gem 'blast_core', path: './engines/core'

rails g modular:engine engines/contacts --namespace=Blast

$:.push File.expand_path('lib', __dir__)

# Maintain your gem's version:
require 'blast/contacts/version'

# Describe your gem and declare its dependencies:
Gem::Specification.new do |s|
  s.name        = 'blast_contacts'
  s.version     = Blast::Contacts::VERSION
  s.authors     = ['Devblast']
  s.email       = ['info@devlast.com']
  s.homepage    = 'https://devblast.com'
  s.summary     = "Contact feature for BlastCRM."
  s.description = "Contact feature for BlastCRM."
  s.license     = 'MIT'

  s.files = Dir['{app,config,db,lib}/**/*', 'MIT-LICENSE',
                'Rakefile', 'README.rdoc']

  s.add_dependency 'rails', '~> 5.2.3'

  s.add_dependency 'deface', '~> 1.4.0'
end

.
.
.
gem 'blast_core', path: '../core'

Blast::Core::Engine.routes.draw do
end

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.
.
gem 'blast_core', path: './engines/core'
gem 'blast_contacts', path: './engines/contacts'

9.3. Contact Model

The first step to building the Contacts engine is to create the Contact model. We’ll then work on the controller.

Step 1: Navigate to the Contacts engine folder and run bundle install

Step 2: Generate the Contact model

rails g model Contact first_name:string last_name:string company:string \
email:string phone:string user:references --no-test-framework

Step 3: Correct the users reference

You will notice that the migration that was created contains the line:

t.references :user, foreign_key: true

Although this is technically correct, if you try and add a Contact you will be faced with a

SQLite3::SQLException: no such table: main.users

error. This is because our User table is not called users but blast_users. To fix this, we simply need to update the reference line to reflect that table name, as shown below:

t.references :user, foreign_key: { to_table: :blast_users }

Step 4: Migrate!

Run rails db:migrate from the parent app folder.

That’s it! Now to add the Contacts Controller.

9.4. Pushing Our Changes

Once again,

1. Check the changes:

   git status
   

2. Stage them:

   git add .
   

3. Commit them:

   git commit -m "Added Contacts engine and added the Contact Model"
   

4. Push to your GitHub repo if you’ve configured it:

   git push origin Chapter-9
   

9.5. Wrap Up

In this chapter we created our first business module, the Contacts module. We did this in a much quicker way by using Thibault’s modular_engine gem, and we created our first model, the Contact model. Finally, we integrated it with the Core module.