Why is my image attribute showing up as nil in post request? - ruby-on-rails

Question

Here's what shows in the server window when submitting the form:
Started POST "/seniors" for 127.0.0.1 at 2013-08-21 17:27:34 -0400
Processing by SeniorsController#create as HTML
Parameters: {"utf8"=>"√", "authenticity_token"=>"zWeveRhstI178IawtOka6TV2wdKwnpKq2J74VYYNf1U=", "senior"=>{"first_name"=>"Jane", "last_name"=>"dOE", "employer _id"=>"1"}, "commit"=>"Create Senior"}
(0.0ms) begin transaction
SQL (3.0ms) INSERT INTO "seniors" ("created_at", "employer_id", "first_name", "image", "last_name", "updated_at") VALUES (?, ?, ?, ?, ?, ?) [["created_at", Wed, 21 Aug 2013 21:27:34 UTC +00:00], ["employer_id", 1], ["first_name", "Jane"], ["image", nil], ["last_name", "dOE"], ["updated_at", Wed , 21 Aug 2013 21:27:34 UTC +00:00]]
(107.7ms) commit transaction
Redirected to http://localhost:3000/seniors
Completed 302 Found in 120ms (ActiveRecord: 110.7ms)
The form:
<%=content_for :page do%>
<div class="menuTitle"><h1><%if #senior.new_record?%>New<%else%>Edit<%end%> Senior</h1></div>
<%=form_for #senior, :html=>{:multipart => true} do |f|%>
<div class="login form">
#<p>First Name: <%=f.text_field :first_name%></p>
<p>Last Name: <%=f.text_field :last_name%></p>
<p>Facility: <%=f.collection_select :employer_id, #employers, :id, :name%></p>
<p>Image: <%=f.file_field :image%></p>
<p><%=f.submit :class => "button red"%></p>
</div>
<%end%>
<%end%>
and model:
class Senior < ActiveRecord::Base
mount_uploader :image, ImageUploader
#attr_accessible :image
#attr_accessible :first_name, :last_name, :street1, :street2, :city, :state, :zipcode, :country, :phone, :image, :employer_id, :phin
attr_protected :nil
has_many :senior_users
has_many :short_forms
has_one :long_form
has_many :users, :as => :workers, :through => :senior_users
belongs_to :employer
def long_name
"#{self.last_name}, #{self.first_name}"
end
end
and image_uploader.rb:
# encoding: utf-8
class ImageUploader < CarrierWave::Uploader::Base
# Include RMagick or MiniMagick support:
#include CarrierWave::RMagick
# include CarrierWave::MiniMagick
# Choose what kind of storage to use for this uploader:
storage :file
# storage :fog
# Override the directory where uploaded files will be stored.
# This is a sensible default for uploaders that are meant to be mounted:
def store_dir
"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
end
# Provide a default URL as a default if there hasn't been a file uploaded:
# def default_url
# # For Rails 3.1+ asset pipeline compatibility:
# # ActionController::Base.helpers.asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
#
# "/images/fallback/" + [version_name, "default.png"].compact.join('_')
# end
# Process files as they are uploaded:
# process :scale => [200, 300]
#
# def scale(width, height)
# # do something
# end
# Create different versions of your uploaded files:
# version :thumb do
# process :scale => [50, 50]
# end
# Add a white list of extensions which are allowed to be uploaded.
# For images you might use something like this:
# def extension_white_list
# %w(jpg jpeg gif png)
# end
# Override the filename of the uploaded files:
# Avoid using model.id or version_name here, see uploader/store.rb for details.
# def filename
# "something.jpg" if original_filename
# end
end

Answer 1

Problem solved thanks to the answer here: Rails file_field does not upload anything
The site I was brought on board to work on uses jQuery mobile which by default submits all forms using ajax, however files cannot be submitted via ajax. The solution was to add
:html => { :'data-ajax' => false }
to the form.

Answer 2

Im leaving this answer if anyone comes here again. Although it's true rails form_for POST via ajax does not support sending files via AJAX even with multipart: true, it can be done with the gem "remotipart". This way, there's no need to fallback to submit the form with full page refresh. In response to #xxyyxx answer.