lib/paperclip/interpolations.rb
module Paperclip
# This module contains all the methods that are available for interpolation
# in paths and urls. To add your own (or override an existing one), you
# can either open this module and define it, or call the
# Paperclip.interpolates method.
module Interpolations
extend self
ID_PARTITION_LIMIT = 1_000_000_000
# Hash assignment of interpolations. Included only for compatibility,
# and is not intended for normal use.
def self.[]= name, block
define_method(name, &block)
@interpolators_cache = nil
end
# Hash access of interpolations. Included only for compatibility,
# and is not intended for normal use.
def self.[] name
method(name)
end
# Returns a sorted list of all interpolations.
def self.all
self.instance_methods(false).sort!
end
# Perform the actual interpolation. Takes the pattern to interpolate
# and the arguments to pass, which are the attachment and style name.
# You can pass a method name on your record as a symbol, which should turn
# an interpolation pattern for Paperclip to use.
def self.interpolate pattern, *args
pattern = args.first.instance.send(pattern) if pattern.kind_of? Symbol
result = pattern.dup
interpolators_cache.each do |method, token|
result.gsub!(token) { send(method, *args) } if result.include?(token)
end
result
end
def self.interpolators_cache
@interpolators_cache ||= all.reverse!.map! { |method| [method, ":#{method}"] }
end
def self.plural_cache
@plural_cache ||= PluralCache.new
end
# Returns the filename, the same way as ":basename.:extension" would.
def filename attachment, style_name
[ basename(attachment, style_name), extension(attachment, style_name) ].delete_if(&:empty?).join(".".freeze)
end
# Returns the interpolated URL. Will raise an error if the url itself
# contains ":url" to prevent infinite recursion. This interpolation
# is used in the default :path to ease default specifications.
RIGHT_HERE = "#{__FILE__.gsub(%r{\A\./}, "")}:#{__LINE__ + 3}"
def url attachment, style_name
raise Errors::InfiniteInterpolationError if caller.any?{|b| b.index(RIGHT_HERE) }
attachment.url(style_name, :timestamp => false, :escape => false)
end
# Returns the timestamp as defined by the <attachment>_updated_at field
# in the server default time zone unless :use_global_time_zone is set
# to false. Note that a Rails.config.time_zone change will still
# invalidate any path or URL that uses :timestamp. For a
# time_zone-agnostic timestamp, use #updated_at.
def timestamp attachment, style_name
attachment.instance_read(:updated_at).in_time_zone(attachment.time_zone).to_s
end
# Returns an integer timestamp that is time zone-neutral, so that paths
# remain valid even if a server's time zone changes.
def updated_at attachment, style_name
attachment.updated_at
end
# Returns the Rails.root constant.
def rails_root attachment, style_name
Rails.root
end
# Returns the Rails.env constant.
def rails_env attachment, style_name
Rails.env
end
# Returns the underscored, pluralized version of the class name.
# e.g. "users" for the User class.
# NOTE: The arguments need to be optional, because some tools fetch
# all class names. Calling #class will return the expected class.
def class attachment = nil, style_name = nil
return super() if attachment.nil? && style_name.nil?
plural_cache.underscore_and_pluralize_class(attachment.instance.class)
end
# Returns the basename of the file. e.g. "file" for "file.jpg"
def basename attachment, style_name
File.basename(attachment.original_filename, ".*".freeze)
end
# Returns the extension of the file. e.g. "jpg" for "file.jpg"
# If the style has a format defined, it will return the format instead
# of the actual extension.
def extension attachment, style_name
((style = attachment.styles[style_name.to_s.to_sym]) && style[:format]) ||
File.extname(attachment.original_filename).sub(/\A\.+/, "".freeze)
end
# Returns the dot+extension of the file. e.g. ".jpg" for "file.jpg"
# If the style has a format defined, it will return the format instead
# of the actual extension. If the extension is empty, no dot is added.
def dotextension attachment, style_name
ext = extension(attachment, style_name)
ext.empty? ? ext : ".#{ext}"
end
# Returns an extension based on the content type. e.g. "jpeg" for
# "image/jpeg". If the style has a specified format, it will override the
# content-type detection.
#
# Each mime type generally has multiple extensions associated with it, so
# if the extension from the original filename is one of these extensions,
# that extension is used, otherwise, the first in the list is used.
def content_type_extension attachment, style_name
mime_type = MIME::Types[attachment.content_type]
extensions_for_mime_type = unless mime_type.empty?
mime_type.first.extensions
else
[]
end
original_extension = extension(attachment, style_name)
style = attachment.styles[style_name.to_s.to_sym]
if style && style[:format]
style[:format].to_s
elsif extensions_for_mime_type.include? original_extension
original_extension
elsif !extensions_for_mime_type.empty?
extensions_for_mime_type.first
else
# It's possible, though unlikely, that the mime type is not in the
# database, so just use the part after the '/' in the mime type as the
# extension.
%r{/([^/]*)\z}.match(attachment.content_type)[1]
end
end
# Returns the id of the instance.
def id attachment, style_name
attachment.instance.id
end
# Returns the #to_param of the instance.
def param attachment, style_name
attachment.instance.to_param
end
# Returns the fingerprint of the instance.
def fingerprint attachment, style_name
attachment.fingerprint
end
# Returns a the attachment hash. See Paperclip::Attachment#hash_key for
# more details.
def hash attachment=nil, style_name=nil
if attachment && style_name
attachment.hash_key(style_name)
else
super()
end
end
# Returns the id of the instance in a split path form. e.g. returns
# 000/001/234 for an id of 1234.
def id_partition attachment, style_name
case id = attachment.instance.id
when Integer
if id < ID_PARTITION_LIMIT
("%09d".freeze % id).scan(/\d{3}/).join("/".freeze)
else
("%012d".freeze % id).scan(/\d{3}/).join("/".freeze)
end
when String
id.scan(/.{3}/).first(3).join("/".freeze)
else
nil
end
end
# Returns the pluralized form of the attachment name. e.g.
# "avatars" for an attachment of :avatar
def attachment attachment, style_name
plural_cache.pluralize_symbol(attachment.name)
end
# Returns the style, or the default style if nil is supplied.
def style attachment, style_name
style_name || attachment.default_style
end
end
end