Using Omnicontacts to get mail contacts from Google #Ruby

Today, when I'm working on company, my colleague asked me: "Do you use Omnicontacts gem to get mail contacts from Google?". After 30 minutes research about this gem, now I'll write a post "Using Omnicontacts to get mail contacts from Google".

First, create new rails app:

    mkdir omnicontacts
    cd omnicontacts/
    rails new .

After run command bundle install, let's add OmniContacts into Gemfile as a dependency:

    gem 'omnicontacts'

bundle install again.

You need generate a controller to handle callback returned from Google.

rails g controller main index contact

    class MainController < ApplicationController
        def index
        end
        def contact
        end
    end

As for Omniauth, let's go to /config/initializers/ directory and create new file omnicontacts.rb

    require 'omnicontacts'

    Rails.application.middleware.use OmniContacts::Builder do
        importer :gmail, "client_id", "client_secret, {:redirect_path => "/oauth2callback", :ssl_ca_path => "/etc/ssl/certs/curl-ca-bundle.crt"}
    end

To add client_id and client_secret, please access Google API Console and Create new Client ID

After generated main_controller, let's update the routes file:

    Omnicontacts::Application.routes.draw do
        match "/contacts/:importer/callback" => "main#index", :via => [:get]
        match "/oauth2callback" => "main#contact", :via => [:get]
        # You can have the root of your site routed with "root"
        root 'main#index'
    end

The list of contacts will be accesses via the omnicontacts.contact key in the environment hash. So, please edit the main_controller file:

    class MainController < ApplicationController
        def index
        end
        def contact
            @contacts = request.env['omnicontacts.contacts']
            respond_to do |format|
                format.html 
            end
        end
    end

After that, we need edit two files in Views folder

/main/index.html.erb

    <h2>OmniContacts Example</h2>

    <a href="/contacts/gmail">Gmail</a>

/main/contact.html.erb

    <% unless @contacts.nil?%>
        <% @contacts.each do |c|%>
            <ul>
                <li><%= c[:name]%> :  <%= c[:email]%></li>
            </ul> 
        <%end%>
    <%end%>

Done, now you can run rails s and access to http://localhost:3000.

Using Omnicontacts to get mail contacts from Google

You can refer example at link: http://omnicontactsvinhnguyen.herokuapp.com/ or https://github.com/vinhnguyenleasnet/omnicontactvinhnguyen