Rails 3.1: Determine if asset exists

Solution 1:

Given an 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

Solution 2:

Since this is still the top question when searching Google, and since the accepted answer does not work properly in production (at least in some cases), here is the solution that works for me (Rails 4.x to 6.x at least):

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

Solution 3:

See this answer: https://stackoverflow.com/a/8217598/549252

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