Rails/Actionmailer error trying to edit email - ruby-on-rails

Question

I'm using rails 4 and actionmailer to allow users to edit a generated email before letting it send.
When I try to load the editing page, I get this error.
Showing /var/www/rqm3/app/views/rfis/mail.html.erb where line #5 raised:
undefined method `body' for nil:NilClass
Here's line 5 for referrence.
<%= text_area_tag :email_body, #mail_message.html_part.body.raw_source,class:"tinymce", rows:40, cols:120 %>
I have #mail_message set from my controller here.
def mail
#mail_message = RfiMailer.send_rfi(current_user, #rfi)
end
Thanks to anyone that helps.
EDIT:
rfis_controller:
class RfisController < ApplicationController
before_action :set_rfi, only: [:show, :edit, :update, :destroy, :mail]
before_action :authenticate_user!
# GET /rfis
# GET /rfis.json
def index
#rfis = Rfi.all
end
# GET /rfis/1
# GET /rfis/1.json
def show
end
# GET /rfis/new
def new
#rfi = Rfi.new
end
# GET /rfis/1/edit
def edit
end
def send_rfi
end
def mail
#mail_message = RfiMailer.send_rfi(current_user)
# #mail_message = RfqMailer.placeholder_message(current_user, Rfq.last)
end
# POST /rfis
# POST /rfis.json
def create
#rfi = Rfi.new(rfi_params)
respond_to do |format|
if #rfi.save
format.html { redirect_to mail_rfi_url(#rfi), notice: 'Rfi was successfully created.' }
format.json { render :show, status: :created, location: #rfi }
else
format.html { render :new }
format.json { render json: #rfi.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /rfis/1
# PATCH/PUT /rfis/1.json
def update
respond_to do |format|
if #rfi.update(rfi_params)
format.html { redirect_to #rfi, notice: 'Rfi was successfully updated.' }
format.json { render :show, status: :ok, location: #rfi }
else
format.html { render :edit }
format.json { render json: #rfi.errors, status: :unprocessable_entity }
end
end
end
# DELETE /rfis/1
# DELETE /rfis/1.json
def destroy
#rfi.destroy
respond_to do |format|
format.html { redirect_to rfis_url, notice: 'Rfi was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_rfi
#rfi = Rfi.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def rfi_params
params.require(:rfi).permit(:due, :rfi_type, :parties, :reference, :svg_ref, :vendor_ref, :email_body)
end
end
rfi_mailer.rb
class RfiMailer < ApplicationMailer
default from:"test#test.com"
def send_rfi(user)
mail(to:"someemail", subject:"test")
end
end

Answer 1

first of all, some cleanup
before_action :set_rfi, only: [:show, :edit, :update, :destroy, :mail]
you can also write
before_action :set_rfi, except: [:index, :new]
back to topic
html_part is nil, thats why you cant use the body of it and it throws a exception.
please make sure that your email is having 2 templates, one for the text-part and one for the html-part. further details on that at the rails Doc
http://guides.rubyonrails.org/action_mailer_basics.html#mailer-views