```ruby
class RedactorRails::Document < RedactorRails::Asset
  mount_uploader :data, RedactorRailsDocumentUploader, :mount_on => :data_file_name

  def url_content
    url(:content)
  end
end
```

Remove thumb from Document's json methods
user
```ruby
class RedactorRails::Document < RedactorRails::Asset
  mount_uploader :data, RedactorRailsDocumentUploader, :mount_on => :data_file_name

  def url_content
    url(:content)
  end

  def as_json_methods
    [:image]
  end
end
```
assistant