require "pathname"
require "active_support/core_ext/class"
require "action_view/template"
module ActionView
# = Action View Resolver
class Resolver
# Keeps all information about view path and builds virtual path.
class Path < String
attr_reader :name, :prefix, :partial, :virtual
alias_method :partial?, :partial
def self.build(name, prefix, partial)
virtual = ""
virtual << "#{prefix}/" unless prefix.empty?
virtual << (partial ? "_#{name}" : name)
new name, prefix, partial, virtual
end
def initialize(name, prefix, partial, virtual)
@name, @prefix, @partial = name, prefix, partial
super(virtual)
end
end
cattr_accessor :caching
self.caching = true
class << self
alias :caching? :caching
end
def initialize
@cached = Hash.new { |h1,k1| h1[k1] = Hash.new { |h2,k2|
h2[k2] = Hash.new { |h3,k3| h3[k3] = Hash.new { |h4,k4| h4[k4] = {} } } } }
end
def clear_cache
@cached.clear
end
# Normalizes the arguments and passes it on to find_template.
def find_all(name, prefix=nil, partial=false, details={}, key=nil, locals=[])
cached(key, [name, prefix, partial], details, locals) do
find_templates(name, prefix, partial, details)
end
end
private
delegate :caching?, :to => "self.class"
# This is what child classes implement. No defaults are needed
# because Resolver guarantees that the arguments are present and
# normalized.
def find_templates(name, prefix, partial, details)
raise NotImplementedError, "Subclasses must implement a find_templates(name, prefix, partial, details) method"
end
# Helpers that builds a path. Useful for building virtual paths.
def build_path(name, prefix, partial)
Path.build(name, prefix, partial)
end
# Handles templates caching. If a key is given and caching is on
# always check the cache before hitting the resolver. Otherwise,
# it always hits the resolver but check if the resolver is fresher
# before returning it.
def cached(key, path_info, details, locals) #:nodoc:
name, prefix, partial = path_info
locals = locals.map { |x| x.to_s }.sort!
if key && caching?
@cached[key][name][prefix][partial][locals] ||= decorate(yield, path_info, details, locals)
else
fresh = decorate(yield, path_info, details, locals)
return fresh unless key
scope = @cached[key][name][prefix][partial]
cache = scope[locals]
mtime = cache && cache.map(&:updated_at).max
if !mtime || fresh.empty? || fresh.any? { |t| t.updated_at > mtime }
scope[locals] = fresh
else
cache
end
end
end
# Ensures all the resolver information is set in the template.
def decorate(templates, path_info, details, locals) #:nodoc:
cached = nil
templates.each do |t|
t.locals = locals
t.formats = details[:formats] || [:html] if t.formats.empty?
t.virtual_path ||= (cached ||= build_path(*path_info))
end
end
end
# An abstract class that implements a Resolver with path semantics.
class PathResolver < Resolver #:nodoc:
EXTENSIONS = [:locale, :formats, :handlers]
DEFAULT_PATTERN = ":prefix/:action{.:locale,}{.:formats,}{.:handlers,}"
def initialize(pattern=nil)
@pattern = pattern || DEFAULT_PATTERN
super()
end
private
def find_templates(name, prefix, partial, details)
path = Path.build(name, prefix, partial)
query(path, details, details[:formats])
end
def query(path, details, formats)
query = build_query(path, details)
# deals with case-insensitive file systems.
sanitizer = Hash.new { |h,dir| h[dir] = Dir["#{dir}/*"] }
template_paths = Dir[query].reject { |filename|
File.directory?(filename) ||
!sanitizer[File.dirname(filename)].include?(filename)
}
template_paths.map { |template|
handler, format = extract_handler_and_format(template, formats)
contents = File.binread template
Template.new(contents, File.expand_path(template), handler,
:virtual_path => path.virtual,
:format => format,
:updated_at => mtime(template))
}
end
# Helper for building query glob string based on resolver's pattern.
def build_query(path, details)
query = @pattern.dup
prefix = path.prefix.empty? ? "" : "#{escape_entry(path.prefix)}\\1"
query.gsub!(/\:prefix(\/)?/, prefix)
partial = escape_entry(path.partial? ? "_#{path.name}" : path.name)
query.gsub!(/\:action/, partial)
details.each do |ext, variants|
query.gsub!(/\:#{ext}/, "{#{variants.compact.uniq.join(',')}}")
end
File.expand_path(query, @path)
end
def escape_entry(entry)
entry.gsub(/[*?{}\[\]]/, '\\\\\\&')
end
# Returns the file mtime from the filesystem.
def mtime(p)
File.mtime(p)
end
# Extract handler and formats from path. If a format cannot be a found neither
# from the path, or the handler, we should return the array of formats given
# to the resolver.
def extract_handler_and_format(path, default_formats)
pieces = File.basename(path).split(".")
pieces.shift
handler = Template.handler_for_extension(pieces.pop)
format = pieces.last && Mime[pieces.last]
[handler, format]
end
end
# A resolver that loads files from the filesystem. It allows setting your own
# resolving pattern. Such pattern can be a glob string supported by some variables.
#
# ==== Examples
#
# Default pattern, loads views the same way as previous versions of rails, eg. when you're
# looking for `users/new` it will produce query glob: `users/new{.{en},}{.{html,js},}{.{erb,haml},}`
#
# FileSystemResolver.new("/path/to/views", ":prefix/:action{.:locale,}{.:formats,}{.:handlers,}")
#
# This one allows you to keep files with different formats in seperated subdirectories,
# eg. `users/new.html` will be loaded from `users/html/new.erb` or `users/new.html.erb`,
# `users/new.js` from `users/js/new.erb` or `users/new.js.erb`, etc.
#
# FileSystemResolver.new("/path/to/views", ":prefix/{:formats/,}:action{.:locale,}{.:formats,}{.:handlers,}")
#
# If you don't specify a pattern then the default will be used.
#
# In order to use any of the customized resolvers above in a Rails application, you just need
# to configure ActionController::Base.view_paths in an initializer, for example:
#
# ActionController::Base.view_paths = FileSystemResolver.new(
# Rails.root.join("app/views"),
# ":prefix{/:locale}/:action{.:formats,}{.:handlers,}"
# )
#
# ==== Pattern format and variables
#
# Pattern has to be a valid glob string, and it allows you to use the
# following variables:
#
# * <tt>:prefix</tt> - usually the controller path
# * <tt>:action</tt> - name of the action
# * <tt>:locale</tt> - possible locale versions
# * <tt>:formats</tt> - possible request formats (for example html, json, xml...)
# * <tt>:handlers</tt> - possible handlers (for example erb, haml, builder...)
#
class FileSystemResolver < PathResolver
def initialize(path, pattern=nil)
raise ArgumentError, "path already is a Resolver class" if path.is_a?(Resolver)
super(pattern)
@path = File.expand_path(path)
end
def to_s
@path.to_s
end
alias :to_path :to_s
def eql?(resolver)
self.class.equal?(resolver.class) && to_path == resolver.to_path
end
alias :== :eql?
end
# An Optimized resolver for Rails' most common case.
class OptimizedFileSystemResolver < FileSystemResolver #:nodoc:
def build_query(path, details)
exts = EXTENSIONS.map { |ext| details[ext] }
query = escape_entry(File.join(@path, path))
query + exts.map { |ext|
"{#{ext.compact.uniq.map { |e| ".#{e}," }.join}}"
}.join
end
end
# The same as FileSystemResolver but does not allow templates to store
# a virtual path since it is invalid for such resolvers.
class FallbackFileSystemResolver < FileSystemResolver #:nodoc:
def self.instances
[new(""), new("/")]
end
def decorate(*)
super.each { |t| t.virtual_path = nil }
end
end
end
