Why doesn't paperclip save uploaded image?

Question

I have a model called employers and I'm using paperclip to upload images. It was working before but for some reason, it has stopped working. I am asking the user to fill a form out with name, company, and a profile pic. In my controller, I have set it so the form doesn't get submitted if something is wrong. The user gets redirected to the homepage if the form gets submitted and the form is rendered again if something is wrong. Right now, the form gets submitted. In my development logs, the name of the picture is also there. My development long looks like this (I am updating the form here, same concept as new form):

Started PATCH "/employers/werwer" for ::1 at 2017-06-28 21:37:15 -0400
Processing by EmployersController#update as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"JeftOiYu26+Vxo/f6NSigrUzHaTsukGvIoGxUVJkH4OGK+HcAs7fH5DWWDHnZiFTYs0/YqN4ZhAYxgwqmSfo7w==", "employer"=>{"name"=>"werwer", "company"=>"werwe", "position"=>"werwer", "number"=>"345345", "email"=>"dinukap999@gmail.com"}, "picture"=>#<ActionDispatch::Http::UploadedFile:0x0000000b570bb0 @tempfile=#<Tempfile:C:/Users/dinuka/AppData/Local/Temp/RackMultipart20170628-7872-a8xds6.png>, @original_filename="icons8-Manager-48.png", @content_type="image/png", @headers="Content-Disposition: form-data; name=\"picture\"; filename=\"icons8-Manager-48.png\"\r\nContent-Type: image/png\r\n">, "commit"=>"Update Employer", "id"=>"werwer"}
  [1m[35mEmployer Load (1.0ms)[0m  SELECT  "employers".* FROM "employers" WHERE "employers"."slug" = ?  ORDER BY "employers"."id" ASC LIMIT 1  [["slug", "werwer"]]
  [1m[36m (1.0ms)[0m  [1mbegin transaction[0m
  [1m[35m (1.0ms)[0m  commit transaction
Redirected to http://localhost:3000/employers/werwer
Completed 302 Found in 35ms (ActiveRecord: 3.0ms)

As you can see, the pic with name "a8xds6.png" is shown on the the third line. But I'm not sure why it's submitted as a temp file.

When I open up the rails console and see the data of that particular employer, everything else except the image is updated. The image says "nil".

This is my form:

<%= simple_form_for @employer do |f| %>
    <%= f.input :name, required: true, label: 'Full name'  %>
    <%= f.input :company, required: true, label: 'Name of company' %>
    <%= f.file_field :emp_img, required: true, name: 'picture' %>
    <%= f.button :submit %>
<% end %>

Controller:

class EmployersController < ApplicationController
    before_action :find_employer, only: [:show, :edit, :update, :destroy]

    def index 
    end

    def show
    end

    def new
        @employer = current_user.build_employer
    end

    def create
        @employer = current_user.build_employer(employer_params)
        if @employer.save
          redirect_to userinfos_path
        else
          render 'new'
        end
    end

    def edit
    end

    def update
        if @employer.update(employer_params)
            redirect_to employer_path(@employer)
        else
            render 'edit'
        end
    end

    def destroy
        @employer.destroy
        redirect_to root_path
    end

    private
        def employer_params          
            params.require(:employer).permit(:name, :company, :emp_img)
        end

        def find_employer
            @employer = Employer.friendly.find(params[:id])
        end 
end

Employer model:

class Employer < ActiveRecord::Base
    belongs_to :user

    has_attached_file :emp_img, :styles => { :profile_pic => "200x200>" }, :default_url => "/images/:style/missing10.png"
    validates_attachment_content_type :emp_img, :content_type => /\Aimage\/.*\Z/
end

View:

<%= image_tag @employer.emp_img.url(:profile_pic) %>

Please let me know what I need to change or if you need any more information. I know the development logs show more parameters than that are in the forms, I removed some params to simplify the question.

Answer 1

Your emp_img file_field should not have a custom name attribute, if you do so you should permit it and add an attr_accessor.

private
    def employer_params          
        params.require(:employer).permit(:name, :company, :emp_img, :picture)
    end

Employer model:

class Employer < ActiveRecord::Base
    [...]
    attr_accessor :picture
    [...]
end

File uploads to server will be saved as a temp file in tmp folder and rails will handle it with ActionDispatch, after your rails object saved the temp file will be moved to the folder that you specified and then save the directory path.

You should remove the name attribute in file_field.

Answer 2

In your form, If you look closely. You can see, you can changed name property to picture which should be emploer[emp_img] .

Due to this emp_imp not present in employer params, and not updating only emp_img .

Try change

<%= f.file_field :emp_img, required: true, name: 'picture' %>

to

<%= f.file_field :emp_img, required: true %>

This will solve your problem.