hellosign_controller.rb

class HellosignController < ApplicationController
	skip_before_action :verify_authenticity_token, only: [:callbacks]

	def callbacks
		respond_to do |format|
			format.json { render json: 'Hello API Event Received', status: 200 }
		end
	end

	def create_embedded_template
		client = HelloSign::Client.new :api_key => ENV['HELLOSIGN_API_KEY']
		request = client.create_embedded_template_draft(
		    :test_mode => 1,
		    :client_id => ENV['HELLOSIGN_CLIENT_ID'],
		    :files => @template.file,
		    :title => @template.title,
		    :subject => @template.subject,
		    :message => @template.message,
		    :signer_roles => [
		        {
		            :name => 'Test Role',
		            :order => 1
		        },
		        {
		            :name => 'Test Role 2',
		            :order => 1
		        }
		    ],
		    :cc_roles => ['Test CC Role'],
		    :merge_fields => '[{"name":"Test Merge","type":"text"},{"name":"Test Merge 2","type":"text"}]'
		)

		new_template_id = request.data['template_id']
		edit_url = request.data['edit_url']
		is_embedded_draft = request.data['is_embedded_draft']
	end

end

template_new.html.erb

<%= form_for(@template, html: {class: 'signup_form well template_form col-md-4 col-md-offset-4'}, multipart: true) do |f| %>
  <% if @template.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@template.errors.count, "error") %> prohibited this template from being saved:</h2>

      <ul>
      <% @template.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :title %><br>
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :subject %><br>
    <%= f.text_field :subject %>
  </div>
  <div class="field">
    <%= f.label :message %><br>
    <%= f.text_area :message %>
  </div>
  <div class="field">
    <%= f.label :file %><br>
    <%= f.file_field :file %>
  </div>
  <div class="actions">
    <%= f.submit 'Start Template', class: 'btn btn-primary' %>
  </div>

<br>
<%= link_to 'Back', templates_path %>
<% end %>

templates_controller.rb

class TemplatesController < ApplicationController
  before_action :set_template, only: [:show, :edit, :update, :destroy]

  # GET /templates
  # GET /templates.json
  def index
    @templates = Template.all
  end

  # GET /templates/1
  # GET /templates/1.json
  def show
  end

  # GET /templates/new
  def new
    @template = Template.new
  end

  # GET /templates/1/edit
  def edit
  end

  # POST /templates
  # POST /templates.json
  def create
    @template = Template.new(template_params)

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

  # PATCH/PUT /templates/1
  # PATCH/PUT /templates/1.json
  def update
    respond_to do |format|
      if @template.update(template_params)
        format.html { redirect_to @template, notice: 'Template was successfully updated.' }
        format.json { render :show, status: :ok, location: @template }
      else
        format.html { render :edit }
        format.json { render json: @template.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /templates/1
  # DELETE /templates/1.json
  def destroy
    @template.destroy
    respond_to do |format|
      format.html { redirect_to templates_url, notice: 'Template was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

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

    # Never trust parameters from the scary internet, only allow the white list through.
    def template_params
      params.require(:template).permit(:title, :subject, :message, :file)
    end
end