Accept Invite

gistfile1.txt

invite_mailer.rb
class InviteMailer < ActionMailer::Base
  default from: "[email protected]"

  def invite_notification(invite, email)
    @invite = invite
    @property = @invite.property
    @url = invite_url(@invite)
    mail(to: @invite.email, subject: "You've been added as a roommate!")
  end

  private

  def invite_url(invite)
    "localhost:3000/invites/accept_invitation?id=#{@invite.id}"
  end
end


application_controller.rb
class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception
  before_filter :make_profile
  before_filter :configure_permitted_parameters, if: :devise_controller?

  layout 'cerulean'

  def after_sign_up_path_for(resource)
    print params
    "localhost:3000/invites/accept_invitation?id=#{@invite.id}"
  end

  private
  
  def make_profile
    if user_signed_in? and current_user.profile.year.nil?
      redirect_to new_profile_path
    end
  end

  #-> Prelang (user_login:devise)
  def require_user_signed_in
    unless user_signed_in?

      # If the user came from a page, we can send them back.  Otherwise, send
      # them to the root path.
      if request.env['HTTP_REFERER']
        fallback_redirect = :back
      elsif defined?(root_path)
        fallback_redirect = root_path
      else
        fallback_redirect = "/"
      end

      redirect_to fallback_redirect, flash: {error: "You must be signed in to view this page."}
    end
  end

  def configure_permitted_parameters
    devise_parameter_sanitizer.for(:sign_up) { |u| u.permit(:email, :password, :password_confirmation, :image, :name, :phone_number, :property_id) }
  end

  def mobile_device?
    request.user_agent =~ /Mobile|webOS/
  end
  helper_method :mobile_device?

end

registrations_controller.rb
class Users::RegistrationsController < Devise::RegistrationsController
  include ApplicationHelper

  def create
    super
    set_property
  end

  def new
    super
  end

  def edit
    super
  end

  def after_user_signed_in
  end

  def set_property
    @property = Property.find(params[:property_id])
    current_user.properties << @property
    puts @property
    puts current_user.properties
  end

end




new.html.erb (registrations)
<div class="row">
  <%= form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f| %>
  <%= devise_error_messages! %>

<form class="form-horizontal">
  <fieldset>
    <legend>Sign up</legend>
    <br>or <%= link_to "Sign in", new_session_path(resource_name) %><br />
        <%= f.hidden_field :name, value: "name"  %>
        <%= hidden_field_tag :property_id, params[:property_id] %>

       <div class="form-group">
        <label for="inputEmail" class="col-lg-2 control-label">Avatar</label>
        <div class="col-lg-10">
          <%= f.file_field :avatar, class: "form-control" %>
        </div>
      </div>

    <div class="form-group">
      <label for="inputEmail" class="col-lg-2 control-label">Email</label>
      <div class="col-lg-10">
        <%= f.email_field :email, autofocus: true, placeholder: "Enter your Drexel email. Ex: [email protected]", class: "form-control", id: "inputEmail" %>
      </div>
    </div>
       <div class="form-group">
      <label for="inputPassword" class="col-lg-2 control-label">Password</label>
      <div class="col-lg-10">
        <%= f.password_field :password, autocomplete: "off", placeholder: "please don't say password", class: "form-control" %>
      </div>
    </div>
    <div class="form-group">
      <label for="inputPassword" class="col-lg-2 control-label">Password Confirmation</label>
      <div class="col-lg-10">
        <%= f.password_field :password_confirmation, autocomplete: "off", placeholder: "we're warning you", class: "form-control" %>
      </div>
    </div>
    <div class="form-group">
      <label for="inputPassword" class="col-lg-2 control-label">Phone number</label>
      <div class="col-lg-10">
        <%= f.text_field :phone_number, placeholder: "Your number will always remain anonymous", class: "form-control", id: "inputEmail" %>
      </div>
    </div>
    <div class="form-group">
      <div class="col-lg-10 col-lg-offset-2">
        <%= f.submit "Sign up", class: "btn btn-primary" %>      
      </div>
    </div>
  </fieldset>
</form>
<% end %>

<%= render "devise/shared/links" %><br><br>
<a href="http://eepurl.com/RClAb">Wait, I'm a landlord!</a> / <a href="http://eepurl.com/RCkWr">Wait, I'm not a Drexel student!</a><br><br><br><br><br><br><br>
</div>
</div>

invites_controller.rb
class InvitesController < ApplicationController
  def new
    load_property
    @invite = @property.invites.build
  end
  
  def create
    load_property
    @invite = @property.invites.new(invite_params)
    
    if @invite.save
      invite_roommates
      redirect_to @property.listing
    else
      render :new 
    end  
  end

  def accept_invitation
    @invite = Invite.find(params[:id])
    @property = @invite.property
    redirect_to new_user_registration_path(property_id: @property.id)
  end
  
  private
  
    def load_property
      @property = Property.find(params[:property_id])
    end

    def invite_roommates
      emails = params[:invite][:email].split(',').map(&:strip).select(&:present?)
      
      emails.each do |email|
        InviteMailer.invite_notification(@invite, @invite.email).deliver
      end
    end
    
    def invite_params
      params.require(:invite).permit(:token, :email)
    end
end



Advice:
Here's what you should try to tease out:
1) Is your set method not working
As in, is there a better way to assign the variable.  Even if you use forceful methods like the one's I'm proposing above, you simply want to figure out if the object you're assigning it to is protected or immutable
2) Are you saving the property_id to the database properly.