Rails 5, “nil is not a valid asset source”

Question

I have just upgraded to Rails 5 and I have a weird issue while trying to show an image.

I have the exact code I had for Rails 4:

<%= image_tag article         


        

Answer 1

I don't know this is compact solution or not but this code will work.

activate the fallback method in your uploader.

  def default_url
    "/assets/fallback/" + [version_name, "default.png"].compact.join('_')
  end

Hope this will help you.

Cheers (y)

Answer 2

The problem was that I was trying to show an image that did not exist.

Adding unless article.image.blank? solved it:

<%= image_tag article.image_url(:thumb) unless article.image.blank? %>

EDIT: In Rails 4, this would have just rendered nothing without errors, while in Rails 5 it raises an error. So it was, in fact, an upgrade issue.

Big thanks to @BookOfGreg for pointing this out.

Answer 3

Try with this, you need to add unless condition in your code. You need to add below code

<%= image_tag article.image_url(:thumb) unless article.image.blank? %>

Answer 4

I hope this code snippet will help those future readers.

<td><%= image_tag image.picture.url, size: "100x100" unless image.picture.url.blank? %></td>

without that unless image.picture.url.blank? part of the code,

"nil is not a valid asset source"

shows up when uploading empty image.