Rails 4, submitting a form by ajax and uploading an image by paperclip gives error: InvalidAuthenticityToken

Question

Using rails 4, I am submitting a form by ajax using remote: true in for_for tag. I have a field to upload image in the form, for image upload paperclip is used.

If I submit the form without uploading image everything works fine. But If I upload a image and then submit the same form I get following error:

ActionController::InvalidAuthenticityToken(ActionController::InvalidAuthenticityToken)

I tried using, "authenticity_token: true" as follows:

<%= form_for @user, :remote => true, authenticity_token: true, :html=>{:class=>"form_validation ", :multipart=>true }  do |f| %>

This above piece of code does not give me InvalidAuthenticityToken error but the form is submitted by html and not js(ajax). I want to submit form by ajax.

Is this a CSRF issue or any other issue related to paperclip? Can anyone help me out with this issue.

Answer 1

You cannot directly upload files by ajax, you need to use jQuery Form or jQuery-File-Upload plugins to make it possible. You need to go through their documentation. Take a look at this question

form_tag with remote: true does not make an ajax request

Answer 2

Please read links below and I am sure you will find something useful:

rails 4 authenticity token

https://github.com/rails/rails/blob/master/actionpack/lib/action_controller/metal/request_forgery_protection.rb?source=cc