Question

I’m using a transparent PNG with the Google IE fix library. This fix only works on images urls that end in “-trans.png”.

Rails’ timestamp-based caching is causing problems with this. When I use image_path() to generate the URL for the image, it appends the file’s last-modified timestamp to the image’s query string. Since the URL no longer ends in “-trans.png” (instead ending in “?” plus a long integer), Google’s javascript fails to activate.

I don’t want to disable asset caching entirely; just on certain images. I also don’t want to hardcode a relative URL to the root of the server. I want to use Rails to generate the URL correctly if the site is deployed to the server root or an (unknown) subdirectory.

What options do I have?

Answer 1

# apologies I'm doing this off the cuff and haven't run-tested this code
alias_method_chain :image_path, :google_sense

def image_path_with_google_sense(source)
  raw_image_path = image_path_without_google_sense(source)
  if source.end_with?('-trans.png')
    # strip off the time stamp
    raw_image_path.split('?').first
  else
    raw_image_path
  end
end