require 'zlib'
require 'active_support/core_ext/file'
module ActionView
class AssetPaths #:nodoc:
URI_REGEXP = %r{^[-a-z]+://|^(?:cid|data):|^//}
attr_reader :config, :controller
def initialize(config, controller = nil)
@config = config
@controller = controller
end
# Add the extension +ext+ if not present. Return full or scheme-relative URLs otherwise untouched.
# Prefix with /dir/ if lacking a leading +/+. Account for relative URL
# roots. Rewrite the asset path for cache-busting asset ids. Include
# asset host, if configured, with the correct request protocol.
#
# When :relative (default), the protocol will be determined by the client using current protocol
# When :request, the protocol will be the request protocol
# Otherwise, the protocol is used (E.g. :http, :https, etc)
def compute_public_path(source, dir, options = {})
source = source.to_s
return source if is_uri?(source)
source = rewrite_extension(source, dir, options[:ext]) if options[:ext]
source = rewrite_asset_path(source, dir, options)
source = rewrite_relative_url_root(source, relative_url_root)
source = rewrite_host_and_protocol(source, options[:protocol])
source
end
# Return the filesystem path for the source
def compute_source_path(source, dir, ext)
source = rewrite_extension(source, dir, ext) if ext
sources = []
sources << config.assets_dir
sources << dir unless source[0] == ?/
sources << source
File.join(sources)
end
def is_uri?(path)
path =~ URI_REGEXP
end
private
def rewrite_extension(source, dir, ext)
raise NotImplementedError
end
def rewrite_asset_path(source, path = nil)
raise NotImplementedError
end
def rewrite_relative_url_root(source, relative_url_root)
relative_url_root && !source.starts_with?("#{relative_url_root}/") ? "#{relative_url_root}#{source}" : source
end
def has_request?
controller.respond_to?(:request)
end
def rewrite_host_and_protocol(source, protocol = nil)
host = compute_asset_host(source)
if host && !is_uri?(host)
if (protocol || default_protocol) == :request && !has_request?
host = nil
else
host = "#{compute_protocol(protocol)}#{host}"
end
end
host ? "#{host}#{source}" : source
end
def compute_protocol(protocol)
protocol ||= default_protocol
case protocol
when :relative
"//"
when :request
unless @controller
invalid_asset_host!("The protocol requested was :request. Consider using :relative instead.")
end
@controller.request.protocol
else
"#{protocol}://"
end
end
def default_protocol
@config.default_asset_host_protocol || (has_request? ? :request : :relative)
end
def invalid_asset_host!(help_message)
raise ActionView::MissingRequestError, "This asset host cannot be computed without a request in scope. #{help_message}"
end
# Pick an asset host for this source. Returns +nil+ if no host is set,
# the host if no wildcard is set, the host interpolated with the
# numbers 0-3 if it contains %d (the number is the source hash mod 4),
# or the value returned from invoking call on an object responding to call
# (proc or otherwise).
def compute_asset_host(source)
if host = asset_host_config
if host.respond_to?(:call)
args = [source]
arity = arity_of(host)
if (arity > 1 || arity < -2) && !has_request?
invalid_asset_host!("Remove the second argument to your asset_host Proc if you do not need the request, or make it optional.")
end
args << current_request if (arity > 1 || arity < 0) && has_request?
host.call(*args)
else
(host =~ /%d/) ? host % (Zlib.crc32(source) % 4) : host
end
end
end
def relative_url_root
config.relative_url_root || current_request.try(:script_name)
end
def asset_host_config
config.asset_host
end
# Returns the current request if one exists.
def current_request
controller.request if has_request?
end
# Returns the arity of a callable
def arity_of(callable)
callable.respond_to?(:arity) ? callable.arity : callable.method(:call).arity
end
end
end