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rails--rails/actionpack/lib/action_view/helpers/asset_url_helper.rb
Piotr Sarnacki 445f14e975 Fix asset_path in mounted engine
Historically serving assets from a mountable engine could be achieved by
running ActionDispatch::Static as a part of engine middleware stack or
to copy assets prefixed with an engine name. After introduction of
assets pipeline this is not needed as all of the assets are served or
compiled into main application's assets.

This commit removes the obsolete line making asset_path always generate
paths relative to the root or config.relative_url_root if it's set.

(closes #8119)
2013-01-21 21:21:39 +01:00

354 lines
17 KiB
Ruby

require 'zlib'
module ActionView
# = Action View Asset URL Helpers
module Helpers
# This module provides methods for generating asset paths and
# urls.
#
# image_path("rails.png")
# # => "/assets/rails.png"
#
# image_url("rails.png")
# # => "http://www.example.com/assets/rails.png"
#
# === Using asset hosts
#
# By default, Rails links to these assets on the current host in the public
# folder, but you can direct Rails to link to assets from a dedicated asset
# server by setting <tt>ActionController::Base.asset_host</tt> in the application
# configuration, typically in <tt>config/environments/production.rb</tt>.
# For example, you'd define <tt>assets.example.com</tt> to be your asset
# host this way, inside the <tt>configure</tt> block of your environment-specific
# configuration files or <tt>config/application.rb</tt>:
#
# config.action_controller.asset_host = "assets.example.com"
#
# Helpers take that into account:
#
# image_tag("rails.png")
# # => <img alt="Rails" src="http://assets.example.com/assets/rails.png" />
# stylesheet_link_tag("application")
# # => <link href="http://assets.example.com/assets/application.css" media="screen" rel="stylesheet" />
#
# Browsers typically open at most two simultaneous connections to a single
# host, which means your assets often have to wait for other assets to finish
# downloading. You can alleviate this by using a <tt>%d</tt> wildcard in the
# +asset_host+. For example, "assets%d.example.com". If that wildcard is
# present Rails distributes asset requests among the corresponding four hosts
# "assets0.example.com", ..., "assets3.example.com". With this trick browsers
# will open eight simultaneous connections rather than two.
#
# image_tag("rails.png")
# # => <img alt="Rails" src="http://assets0.example.com/assets/rails.png" />
# stylesheet_link_tag("application")
# # => <link href="http://assets2.example.com/assets/application.css" media="screen" rel="stylesheet" />
#
# To do this, you can either setup four actual hosts, or you can use wildcard
# DNS to CNAME the wildcard to a single asset host. You can read more about
# setting up your DNS CNAME records from your ISP.
#
# Note: This is purely a browser performance optimization and is not meant
# for server load balancing. See http://www.die.net/musings/page_load_time/
# for background.
#
# Alternatively, you can exert more control over the asset host by setting
# +asset_host+ to a proc like this:
#
# ActionController::Base.asset_host = Proc.new { |source|
# "http://assets#{Digest::MD5.hexdigest(source).to_i(16) % 2 + 1}.example.com"
# }
# image_tag("rails.png")
# # => <img alt="Rails" src="http://assets1.example.com/assets/rails.png" />
# stylesheet_link_tag("application")
# # => <link href="http://assets2.example.com/assets/application.css" media="screen" rel="stylesheet" />
#
# The example above generates "http://assets1.example.com" and
# "http://assets2.example.com". This option is useful for example if
# you need fewer/more than four hosts, custom host names, etc.
#
# As you see the proc takes a +source+ parameter. That's a string with the
# absolute path of the asset, for example "/assets/rails.png".
#
# ActionController::Base.asset_host = Proc.new { |source|
# if source.ends_with?('.css')
# "http://stylesheets.example.com"
# else
# "http://assets.example.com"
# end
# }
# image_tag("rails.png")
# # => <img alt="Rails" src="http://assets.example.com/assets/rails.png" />
# stylesheet_link_tag("application")
# # => <link href="http://stylesheets.example.com/assets/application.css" media="screen" rel="stylesheet" />
#
# Alternatively you may ask for a second parameter +request+. That one is
# particularly useful for serving assets from an SSL-protected page. The
# example proc below disables asset hosting for HTTPS connections, while
# still sending assets for plain HTTP requests from asset hosts. If you don't
# have SSL certificates for each of the asset hosts this technique allows you
# to avoid warnings in the client about mixed media.
#
# config.action_controller.asset_host = Proc.new { |source, request|
# if request.ssl?
# "#{request.protocol}#{request.host_with_port}"
# else
# "#{request.protocol}assets.example.com"
# end
# }
#
# You can also implement a custom asset host object that responds to +call+
# and takes either one or two parameters just like the proc.
#
# config.action_controller.asset_host = AssetHostingWithMinimumSsl.new(
# "http://asset%d.example.com", "https://asset1.example.com"
# )
#
module AssetUrlHelper
URI_REGEXP = %r{^[-a-z]+://|^(?:cid|data):|^//}
# Computes the path to asset in public directory. If :type
# options is set, a file extension will be appended and scoped
# to the corresponding public directory.
#
# All other asset *_path helpers delegate through this method.
#
# asset_path "application.js" # => /application.js
# asset_path "application", type: :javascript # => /javascripts/application.js
# asset_path "application", type: :stylesheet # => /stylesheets/application.css
# asset_path "http://www.example.com/js/xmlhr.js" # => http://www.example.com/js/xmlhr.js
def asset_path(source, options = {})
source = source.to_s
return "" unless source.present?
return source if source =~ URI_REGEXP
tail, source = source[/([\?#].+)$/], source.sub(/([\?#].+)$/, '')
if extname = compute_asset_extname(source, options)
source = "#{source}#{extname}"
end
if source[0] != ?/
source = compute_asset_path(source, options)
end
relative_url_root = defined?(config.relative_url_root) && config.relative_url_root
if relative_url_root
source = "#{relative_url_root}#{source}" unless source.starts_with?("#{relative_url_root}/")
end
if host = compute_asset_host(source, options)
source = "#{host}#{source}"
end
"#{source}#{tail}"
end
alias_method :path_to_asset, :asset_path # aliased to avoid conflicts with a asset_path named route
# Computes the full URL to a asset in the public directory. This
# will use +asset_path+ internally, so most of their behaviors
# will be the same.
def asset_url(source, options = {})
path_to_asset(source, options.merge(:protocol => :request))
end
alias_method :url_to_asset, :asset_url # aliased to avoid conflicts with an asset_url named route
ASSET_EXTENSIONS = {
javascript: '.js',
stylesheet: '.css'
}
# Compute extname to append to asset path. Returns nil if
# nothing should be added.
def compute_asset_extname(source, options = {})
return if options[:extname] == false
extname = options[:extname] || ASSET_EXTENSIONS[options[:type]]
extname if extname && File.extname(source) != extname
end
# Maps asset types to public directory.
ASSET_PUBLIC_DIRECTORIES = {
audio: '/audios',
font: '/fonts',
image: '/images',
javascript: '/javascripts',
stylesheet: '/stylesheets',
video: '/videos'
}
# Computes asset path to public directory. Plugins and
# extensions can override this method to point to custom assets
# or generate digested paths or query strings.
def compute_asset_path(source, options = {})
dir = ASSET_PUBLIC_DIRECTORIES[options[:type]] || ""
File.join(dir, source)
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 <tt>%d</tt> (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 = "", options = {})
request = self.request if respond_to?(:request)
host = config.asset_host if defined? config.asset_host
host ||= request.base_url if request && options[:protocol] == :request
return unless host
if host.respond_to?(:call)
arity = host.respond_to?(:arity) ? host.arity : host.method(:call).arity
args = [source]
args << request if request && (arity > 1 || arity < 0)
host = host.call(*args)
elsif host =~ /%d/
host = host % (Zlib.crc32(source) % 4)
end
if host =~ URI_REGEXP
host
else
protocol = options[:protocol] || config.default_asset_host_protocol || (request ? :request : :relative)
case protocol
when :relative
"//#{host}"
when :request
"#{request.protocol}#{host}"
else
"#{protocol}://#{host}"
end
end
end
# Computes the path to a javascript asset in the public javascripts directory.
# If the +source+ filename has no extension, .js will be appended (except for explicit URIs)
# Full paths from the document root will be passed through.
# Used internally by javascript_include_tag to build the script path.
#
# javascript_path "xmlhr" # => /javascripts/xmlhr.js
# javascript_path "dir/xmlhr.js" # => /javascripts/dir/xmlhr.js
# javascript_path "/dir/xmlhr" # => /dir/xmlhr.js
# javascript_path "http://www.example.com/js/xmlhr" # => http://www.example.com/js/xmlhr
# javascript_path "http://www.example.com/js/xmlhr.js" # => http://www.example.com/js/xmlhr.js
def javascript_path(source, options = {})
path_to_asset(source, {type: :javascript}.merge!(options))
end
alias_method :path_to_javascript, :javascript_path # aliased to avoid conflicts with a javascript_path named route
# Computes the full URL to a javascript asset in the public javascripts directory.
# This will use +javascript_path+ internally, so most of their behaviors will be the same.
def javascript_url(source, options = {})
url_to_asset(source, {type: :javascript}.merge!(options))
end
alias_method :url_to_javascript, :javascript_url # aliased to avoid conflicts with a javascript_url named route
# Computes the path to a stylesheet asset in the public stylesheets directory.
# If the +source+ filename has no extension, <tt>.css</tt> will be appended (except for explicit URIs).
# Full paths from the document root will be passed through.
# Used internally by +stylesheet_link_tag+ to build the stylesheet path.
#
# stylesheet_path "style" # => /stylesheets/style.css
# stylesheet_path "dir/style.css" # => /stylesheets/dir/style.css
# stylesheet_path "/dir/style.css" # => /dir/style.css
# stylesheet_path "http://www.example.com/css/style" # => http://www.example.com/css/style
# stylesheet_path "http://www.example.com/css/style.css" # => http://www.example.com/css/style.css
def stylesheet_path(source, options = {})
path_to_asset(source, {type: :stylesheet}.merge!(options))
end
alias_method :path_to_stylesheet, :stylesheet_path # aliased to avoid conflicts with a stylesheet_path named route
# Computes the full URL to a stylesheet asset in the public stylesheets directory.
# This will use +stylesheet_path+ internally, so most of their behaviors will be the same.
def stylesheet_url(source, options = {})
url_to_asset(source, {type: :stylesheet}.merge!(options))
end
alias_method :url_to_stylesheet, :stylesheet_url # aliased to avoid conflicts with a stylesheet_url named route
# Computes the path to an image asset.
# Full paths from the document root will be passed through.
# Used internally by +image_tag+ to build the image path:
#
# image_path("edit") # => "/assets/edit"
# image_path("edit.png") # => "/assets/edit.png"
# image_path("icons/edit.png") # => "/assets/icons/edit.png"
# image_path("/icons/edit.png") # => "/icons/edit.png"
# image_path("http://www.example.com/img/edit.png") # => "http://www.example.com/img/edit.png"
#
# If you have images as application resources this method may conflict with their named routes.
# The alias +path_to_image+ is provided to avoid that. Rails uses the alias internally, and
# plugin authors are encouraged to do so.
def image_path(source, options = {})
path_to_asset(source, {type: :image}.merge!(options))
end
alias_method :path_to_image, :image_path # aliased to avoid conflicts with an image_path named route
# Computes the full URL to an image asset.
# This will use +image_path+ internally, so most of their behaviors will be the same.
def image_url(source, options = {})
url_to_asset(source, {type: :image}.merge!(options))
end
alias_method :url_to_image, :image_url # aliased to avoid conflicts with an image_url named route
# Computes the path to a video asset in the public videos directory.
# Full paths from the document root will be passed through.
# Used internally by +video_tag+ to build the video path.
#
# video_path("hd") # => /videos/hd
# video_path("hd.avi") # => /videos/hd.avi
# video_path("trailers/hd.avi") # => /videos/trailers/hd.avi
# video_path("/trailers/hd.avi") # => /trailers/hd.avi
# video_path("http://www.example.com/vid/hd.avi") # => http://www.example.com/vid/hd.avi
def video_path(source, options = {})
path_to_asset(source, {type: :video}.merge!(options))
end
alias_method :path_to_video, :video_path # aliased to avoid conflicts with a video_path named route
# Computes the full URL to a video asset in the public videos directory.
# This will use +video_path+ internally, so most of their behaviors will be the same.
def video_url(source, options = {})
url_to_asset(source, {type: :video}.merge!(options))
end
alias_method :url_to_video, :video_url # aliased to avoid conflicts with an video_url named route
# Computes the path to an audio asset in the public audios directory.
# Full paths from the document root will be passed through.
# Used internally by +audio_tag+ to build the audio path.
#
# audio_path("horse") # => /audios/horse
# audio_path("horse.wav") # => /audios/horse.wav
# audio_path("sounds/horse.wav") # => /audios/sounds/horse.wav
# audio_path("/sounds/horse.wav") # => /sounds/horse.wav
# audio_path("http://www.example.com/sounds/horse.wav") # => http://www.example.com/sounds/horse.wav
def audio_path(source, options = {})
path_to_asset(source, {type: :audio}.merge!(options))
end
alias_method :path_to_audio, :audio_path # aliased to avoid conflicts with an audio_path named route
# Computes the full URL to an audio asset in the public audios directory.
# This will use +audio_path+ internally, so most of their behaviors will be the same.
def audio_url(source, options = {})
url_to_asset(source, {type: :audio}.merge!(options))
end
alias_method :url_to_audio, :audio_url # aliased to avoid conflicts with an audio_url named route
# Computes the path to a font asset.
# Full paths from the document root will be passed through.
#
# font_path("font") # => /assets/font
# font_path("font.ttf") # => /assets/font.ttf
# font_path("dir/font.ttf") # => /assets/dir/font.ttf
# font_path("/dir/font.ttf") # => /dir/font.ttf
# font_path("http://www.example.com/dir/font.ttf") # => http://www.example.com/dir/font.ttf
def font_path(source, options = {})
path_to_asset(source, {type: :font}.merge!(options))
end
alias_method :path_to_font, :font_path # aliased to avoid conflicts with an font_path named route
# Computes the full URL to a font asset.
# This will use +font_path+ internally, so most of their behaviors will be the same.
def font_url(source, options = {})
url_to_asset(source, {type: :font}.merge!(options))
end
alias_method :url_to_font, :font_url # aliased to avoid conflicts with an font_url named route
end
end
end