Rails CarrierWave store image from url gives Can't convert nil into string

Question

Using CarrierWave and Amazon S3, I'm able to store images from local files, but when I try to store them from certain url, I get 'TypeError: can't convert nil into String'

    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/carrierwave-0.5.8/lib/carrierwave/uploader/cache.rb:149:in `join'
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/carrierwave-0.5.8/lib/carrierwave/uploader/cache.rb:149:in `cache_path'
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/carrierwave-0.5.8/lib/carrierwave/uploader/cache.rb:121:in `block in cache!'
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/carrierwave-0.5.8/lib/carrierwave/uploader/callbacks.rb:17:in `with_callbacks'
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/carrierwave-0.5.8/lib/carrierwave/uploader/cache.rb:112:in `cache!'
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/carrierwave-0.5.8/lib/carrierwave/uploader/store.rb:56:in `store!'
    from (irb):5
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/railties-3.1.3/lib/rails/commands/console.rb:45:in `start'
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/railties-3.1.3/lib/rails/commands/console.rb:8:in `start'
    from /Users/bashar/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/railties-3.1.3/lib/rails/commands.rb:40:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

This is the code I'm trying

require 'open-uri'
image = "open(image_url)
@object.image.store!(file)

obviously @object holds the Uploader image and it's been working fine using local file systems. I tried to add a

def root Rails.root.join 'public/' end

to my uploader as well with no luck.

Any idea?

Answer 1

To tell carrier wave to download a remote url, you use this syntax:

@object.remote_image_url = "http://www.example.com/file.png"
@object.save