require "pathname" require "active_support/core_ext/class" require "active_support/core_ext/module/attribute_accessors" require "action_view/template" require "thread" require "thread_safe" module ActionView # = Action View Resolver class Resolver # Keeps all information about view path and builds virtual path. class Path 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 = name @prefix = prefix @partial = partial @virtual = virtual end def to_str @virtual end alias :to_s :to_str end # Threadsafe template cache class Cache #:nodoc: class SmallCache < ThreadSafe::Cache def initialize(options = {}) super(options.merge(:initial_capacity => 2)) end end # preallocate all the default blocks for performance/memory consumption reasons PARTIAL_BLOCK = lambda {|cache, partial| cache[partial] = SmallCache.new} PREFIX_BLOCK = lambda {|cache, prefix| cache[prefix] = SmallCache.new(&PARTIAL_BLOCK)} NAME_BLOCK = lambda {|cache, name| cache[name] = SmallCache.new(&PREFIX_BLOCK)} KEY_BLOCK = lambda {|cache, key| cache[key] = SmallCache.new(&NAME_BLOCK)} # usually a majority of template look ups return nothing, use this canonical preallocated array to save memory NO_TEMPLATES = [].freeze def initialize @data = SmallCache.new(&KEY_BLOCK) end # Cache the templates returned by the block def cache(key, name, prefix, partial, locals) if Resolver.caching? @data[key][name][prefix][partial][locals] ||= canonical_no_templates(yield) else fresh_templates = yield cached_templates = @data[key][name][prefix][partial][locals] if templates_have_changed?(cached_templates, fresh_templates) @data[key][name][prefix][partial][locals] = canonical_no_templates(fresh_templates) else cached_templates || NO_TEMPLATES end end end def clear @data.clear end private def canonical_no_templates(templates) templates.empty? ? NO_TEMPLATES : templates end def templates_have_changed?(cached_templates, fresh_templates) # if either the old or new template list is empty, we don't need to (and can't) # compare modification times, and instead just check whether the lists are different if cached_templates.blank? || fresh_templates.blank? return fresh_templates.blank? != cached_templates.blank? end cached_templates_max_updated_at = cached_templates.map(&:updated_at).max # if a template has changed, it will be now be newer than all the cached templates fresh_templates.any? { |t| t.updated_at > cached_templates_max_updated_at } end end cattr_accessor :caching self.caching = true class << self alias :caching? :caching end def initialize @cache = Cache.new end def clear_cache @cache.clear end # Normalizes the arguments and passes it on to find_templates. 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: :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 if the key is present, 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(&:to_s).sort! if key @cache.cache(key, name, prefix, partial, locals) do decorate(yield, path_info, details, locals) end else decorate(yield, path_info, details, locals) 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.variants = details[:variants] || [] if t.variants.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 => ".", :variants => "+", :handlers => "." } DEFAULT_PATTERN = ":prefix/:action{.:locale,}{.:formats,}{+:variants,}{.: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) template_paths = find_template_paths query template_paths.map { |template| handler, format, variant = extract_handler_and_format_and_variant(template, formats) contents = File.binread(template) Template.new(contents, File.expand_path(template), handler, :virtual_path => path.virtual, :format => format, :variant => variant, :updated_at => mtime(template) ) } end def find_template_paths(query) Dir[query].reject { |filename| File.directory?(filename) || # deals with case-insensitive file systems. !File.fnmatch(query, filename, File::FNM_EXTGLOB) } 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, formats and variant from path. If a format cannot be found neither # from the path, or the handler, we should return the array of formats given # to the resolver. def extract_handler_and_format_and_variant(path, default_formats) pieces = File.basename(path).split(".") pieces.shift extension = pieces.pop handler = Template.handler_for_extension(extension) format, variant = pieces.last.split(EXTENSIONS[:variants], 2) if pieces.last format &&= Template::Types[format] [handler, format, variant] 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,}{+:variants,}{.:handlers,}") # # This one allows you to keep files with different formats in separate 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,}{+:variants,}{.: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/:action{.:locale,}{.:formats,}{+:variants,}{.:handlers,}", # ) # # ==== Pattern format and variables # # Pattern has to be a valid glob string, and it allows you to use the # following variables: # # * :prefix - usually the controller path # * :action - name of the action # * :locale - possible locale versions # * :formats - possible request formats (for example html, json, xml...) # * :variants - possible request variants (for example phone, tablet...) # * :handlers - 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) query = escape_entry(File.join(@path, path)) exts = EXTENSIONS.map do |ext, prefix| "{#{details[ext].compact.uniq.map { |e| "#{prefix}#{e}," }.join}}" end.join query + exts 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