Rails 4 - Create a button to send email to user onclick

Question

I would like to create a button that send an email to a User when pressed - So i Used ActionMailer - http://guides.rubyonrails.org/action_mailer_basics.html#sending-emails As described from section 2 to 2.1.4 I created:

app/mailers/user_mailer.rb

class UserMailer < ActionMailer::Base
default from: 'myemail@gmail.com'
end

def send_email(user)
  @user = user
  @url  = 'http://example.com/login'
  mail(to: @user.email, subject: 'You receive this email because you click on the btn)
 end
end

So here I don't know what value to put inside @url ?

Then i created a view for my email - But I don't know what to call in my user model to tell it to send the email when the user click on button, here is my app/controllers/user_controller.rb

class UsersController < ApplicationController
  before_action :set_user, only: [:show, :edit, :update, :destroy]
  # GET /users
  # GET /users.json
  def index
    @users = User.all
    @users = User.paginate(:page => params[:page], :per_page => 50)
  end

  # GET /users/1
  # GET /users/1.json
  def show
    @user = User.find(params[:id])
  end

  # GET /users/new
  def new
    @user = User.new
  end

  # GET /users/1/edit
  def edit
  end

  # POST /users
  # POST /users.json
  def create
    @user = User.new(user_params)

    respond_to do |format|
      if @user.save
        format.html { redirect_to @user, notice: 'User was successfully created.' }
        format.json { render action: 'show', status: :created, location: @user }
      else
        format.html { render action: 'new' }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /users/1
  # PATCH/PUT /users/1.json
  def update
    respond_to do |format|
      if @user.update(user_params)
        format.html { redirect_to @user, notice: 'User was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /users/1
  # DELETE /users/1.json


  private
    # Use callbacks to share common setup or constraints between actions.
    def set_user
      @user = User.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def user_params
      params[:user]
    end


   def self.find_for_facebook_oauth(auth)
  where(auth.slice(:provider, :uid)).first_or_create do |user|
    user.provider = auth.provider
    user.uid = auth.uid
    user.email = auth.info.email
    user.password = Devise.friendly_token[0,20]
    user.name = auth.info.name   # assuming the user model has a name
    user.image = auth.info.image # assuming the user model has an image
  end
end


end

Now In my views, I would like the user to receive an email when he is cliking on this button -

<button class="btn btn-default" type="button">Get my reward</button>

Answer 1

From the User model you would call UserMailer.send_email(self). You could put that in a method and call that using a after_save callback so that the email is sent whenever the User updates his/her profile.