Rails 3.1: Asset Determination

Question

Is there a built-in way to determine if an asset exists without resorting to File.exists?(File.join(Rails.root, "foo", "bar", "baz")) , and which looks for resource paths.

My application sends and selects images from a remote server in the Resque queue; until we upload the image, I want to serve as a placeholder image. I am currently using File.exists ... but that means hard-coding a path that sucks or looks at configured asset paths. It seems like it should already be, but I can't find it in the docs.

Answer 1

Given the image in app/assets/images/lolshirts/theme/bg-header.png ,

 Rails.application.assets.find_asset 'lolshirts/theme/bg-header.png' => #> Sprockets::StaticAsset:0x80c388ec pathname="/Users/joevandyk/projects/tanga/sites/lolshirts/app/assets/images/lolshirts/theme/bg-header.png", mtime=2011-10-07 12:34:48 -0700, digest="a63cc84aca38e2172ae25de3d837c71a"> Rails.application.assets.find_asset 'notthere.png' => nil 

Answer 2

Since this is still the main question when searching on Google, and since the accepted answer does not work properly in production (at least in some cases), here is a solution that works for me (Rails 4.2.5.1):

 def asset_exist?(path) if Rails.configuration.assets.compile Rails.application.precompiled_assets.include? path else Rails.application.assets_manifest.assets[path].present? end end 

This is copied from this github issue.

Answer 3

See this answer: stack overflow

 = Rails.application.assets.find_asset("my_asset.css").nil? 

Answer 4

Please see the answer here to discuss why find_asset may not always work:

Include assets only if they exist