aboutsummaryrefslogtreecommitdiffstats
path: root/actionview/lib/action_view/template
diff options
context:
space:
mode:
Diffstat (limited to 'actionview/lib/action_view/template')
-rw-r--r--actionview/lib/action_view/template/error.rb138
-rw-r--r--actionview/lib/action_view/template/handlers.rb53
-rw-r--r--actionview/lib/action_view/template/handlers/builder.rb26
-rw-r--r--actionview/lib/action_view/template/handlers/erb.rb145
-rw-r--r--actionview/lib/action_view/template/handlers/raw.rb11
-rw-r--r--actionview/lib/action_view/template/resolver.rb326
-rw-r--r--actionview/lib/action_view/template/text.rb34
-rw-r--r--actionview/lib/action_view/template/types.rb57
8 files changed, 790 insertions, 0 deletions
diff --git a/actionview/lib/action_view/template/error.rb b/actionview/lib/action_view/template/error.rb
new file mode 100644
index 0000000000..a89d51221e
--- /dev/null
+++ b/actionview/lib/action_view/template/error.rb
@@ -0,0 +1,138 @@
+require "active_support/core_ext/enumerable"
+
+module ActionView
+ # = Action View Errors
+ class ActionViewError < StandardError #:nodoc:
+ end
+
+ class EncodingError < StandardError #:nodoc:
+ end
+
+ class MissingRequestError < StandardError #:nodoc:
+ end
+
+ class WrongEncodingError < EncodingError #:nodoc:
+ def initialize(string, encoding)
+ @string, @encoding = string, encoding
+ end
+
+ def message
+ @string.force_encoding(Encoding::ASCII_8BIT)
+ "Your template was not saved as valid #{@encoding}. Please " \
+ "either specify #{@encoding} as the encoding for your template " \
+ "in your text editor, or mark the template with its " \
+ "encoding by inserting the following as the first line " \
+ "of the template:\n\n# encoding: <name of correct encoding>.\n\n" \
+ "The source of your template was:\n\n#{@string}"
+ end
+ end
+
+ class MissingTemplate < ActionViewError #:nodoc:
+ attr_reader :path
+
+ def initialize(paths, path, prefixes, partial, details, *)
+ @path = path
+ prefixes = Array(prefixes)
+ template_type = if partial
+ "partial"
+ elsif path =~ /layouts/i
+ 'layout'
+ else
+ 'template'
+ end
+
+ searched_paths = prefixes.map { |prefix| [prefix, path].join("/") }
+
+ out = "Missing #{template_type} #{searched_paths.join(", ")} with #{details.inspect}. Searched in:\n"
+ out += paths.compact.map { |p| " * #{p.to_s.inspect}\n" }.join
+ super out
+ end
+ end
+
+ class Template
+ # The Template::Error exception is raised when the compilation or rendering of the template
+ # fails. This exception then gathers a bunch of intimate details and uses it to report a
+ # precise exception message.
+ class Error < ActionViewError #:nodoc:
+ SOURCE_CODE_RADIUS = 3
+
+ attr_reader :original_exception, :backtrace
+
+ def initialize(template, original_exception)
+ super(original_exception.message)
+ @template, @original_exception = template, original_exception
+ @sub_templates = nil
+ @backtrace = original_exception.backtrace
+ end
+
+ def file_name
+ @template.identifier
+ end
+
+ def sub_template_message
+ if @sub_templates
+ "Trace of template inclusion: " +
+ @sub_templates.collect { |template| template.inspect }.join(", ")
+ else
+ ""
+ end
+ end
+
+ def source_extract(indentation = 0, output = :console)
+ return unless num = line_number
+ num = num.to_i
+
+ source_code = @template.source.split("\n")
+
+ start_on_line = [ num - SOURCE_CODE_RADIUS - 1, 0 ].max
+ end_on_line = [ num + SOURCE_CODE_RADIUS - 1, source_code.length].min
+
+ indent = end_on_line.to_s.size + indentation
+ return unless source_code = source_code[start_on_line..end_on_line]
+
+ formatted_code_for(source_code, start_on_line, indent, output)
+ end
+
+ def sub_template_of(template_path)
+ @sub_templates ||= []
+ @sub_templates << template_path
+ end
+
+ def line_number
+ @line_number ||=
+ if file_name
+ regexp = /#{Regexp.escape File.basename(file_name)}:(\d+)/
+ $1 if message =~ regexp || backtrace.find { |line| line =~ regexp }
+ end
+ end
+
+ def annoted_source_code
+ source_extract(4)
+ end
+
+ private
+
+ def source_location
+ if line_number
+ "on line ##{line_number} of "
+ else
+ 'in '
+ end + file_name
+ end
+
+ def formatted_code_for(source_code, line_counter, indent, output)
+ start_value = (output == :html) ? {} : ""
+ source_code.inject(start_value) do |result, line|
+ line_counter += 1
+ if output == :html
+ result.update(line_counter.to_s => "%#{indent}s %s\n" % ["", line])
+ else
+ result << "%#{indent}s: %s\n" % [line_counter, line]
+ end
+ end
+ end
+ end
+ end
+
+ TemplateError = Template::Error
+end
diff --git a/actionview/lib/action_view/template/handlers.rb b/actionview/lib/action_view/template/handlers.rb
new file mode 100644
index 0000000000..d9cddc0040
--- /dev/null
+++ b/actionview/lib/action_view/template/handlers.rb
@@ -0,0 +1,53 @@
+module ActionView #:nodoc:
+ # = Action View Template Handlers
+ class Template
+ module Handlers #:nodoc:
+ autoload :ERB, 'action_view/template/handlers/erb'
+ autoload :Builder, 'action_view/template/handlers/builder'
+ autoload :Raw, 'action_view/template/handlers/raw'
+
+ def self.extended(base)
+ base.register_default_template_handler :erb, ERB.new
+ base.register_template_handler :builder, Builder.new
+ base.register_template_handler :raw, Raw.new
+ base.register_template_handler :ruby, :source.to_proc
+ end
+
+ @@template_handlers = {}
+ @@default_template_handlers = nil
+
+ def self.extensions
+ @@template_extensions ||= @@template_handlers.keys
+ end
+
+ # Register an object that knows how to handle template files with the given
+ # extensions. This can be used to implement new template types.
+ # The handler must respond to `:call`, which will be passed the template
+ # and should return the rendered template as a String.
+ def register_template_handler(*extensions, handler)
+ raise(ArgumentError, "Extension is required") if extensions.empty?
+ extensions.each do |extension|
+ @@template_handlers[extension.to_sym] = handler
+ end
+ @@template_extensions = nil
+ end
+
+ def template_handler_extensions
+ @@template_handlers.keys.map {|key| key.to_s }.sort
+ end
+
+ def registered_template_handler(extension)
+ extension && @@template_handlers[extension.to_sym]
+ end
+
+ def register_default_template_handler(extension, klass)
+ register_template_handler(extension, klass)
+ @@default_template_handlers = klass
+ end
+
+ def handler_for_extension(extension)
+ registered_template_handler(extension) || @@default_template_handlers
+ end
+ end
+ end
+end
diff --git a/actionview/lib/action_view/template/handlers/builder.rb b/actionview/lib/action_view/template/handlers/builder.rb
new file mode 100644
index 0000000000..d90b0c6378
--- /dev/null
+++ b/actionview/lib/action_view/template/handlers/builder.rb
@@ -0,0 +1,26 @@
+module ActionView
+ module Template::Handlers
+ class Builder
+ # Default format used by Builder.
+ class_attribute :default_format
+ self.default_format = :xml
+
+ def call(template)
+ require_engine
+ "xml = ::Builder::XmlMarkup.new(:indent => 2);" +
+ "self.output_buffer = xml.target!;" +
+ template.source +
+ ";xml.target!;"
+ end
+
+ protected
+
+ def require_engine
+ @required ||= begin
+ require "builder"
+ true
+ end
+ end
+ end
+ end
+end
diff --git a/actionview/lib/action_view/template/handlers/erb.rb b/actionview/lib/action_view/template/handlers/erb.rb
new file mode 100644
index 0000000000..c8a0059596
--- /dev/null
+++ b/actionview/lib/action_view/template/handlers/erb.rb
@@ -0,0 +1,145 @@
+require 'erubis'
+
+module ActionView
+ class Template
+ module Handlers
+ class Erubis < ::Erubis::Eruby
+ def add_preamble(src)
+ @newline_pending = 0
+ src << "@output_buffer = output_buffer || ActionView::OutputBuffer.new;"
+ end
+
+ def add_text(src, text)
+ return if text.empty?
+
+ if text == "\n"
+ @newline_pending += 1
+ else
+ src << "@output_buffer.safe_append='"
+ src << "\n" * @newline_pending if @newline_pending > 0
+ src << escape_text(text)
+ src << "';"
+
+ @newline_pending = 0
+ end
+ end
+
+ # Erubis toggles <%= and <%== behavior when escaping is enabled.
+ # We override to always treat <%== as escaped.
+ def add_expr(src, code, indicator)
+ case indicator
+ when '=='
+ add_expr_escaped(src, code)
+ else
+ super
+ end
+ end
+
+ BLOCK_EXPR = /\s+(do|\{)(\s*\|[^|]*\|)?\s*\Z/
+
+ def add_expr_literal(src, code)
+ flush_newline_if_pending(src)
+ if code =~ BLOCK_EXPR
+ src << '@output_buffer.append= ' << code
+ else
+ src << '@output_buffer.append=(' << code << ');'
+ end
+ end
+
+ def add_expr_escaped(src, code)
+ flush_newline_if_pending(src)
+ if code =~ BLOCK_EXPR
+ src << "@output_buffer.safe_append= " << code
+ else
+ src << "@output_buffer.safe_append=(" << code << ");"
+ end
+ end
+
+ def add_stmt(src, code)
+ flush_newline_if_pending(src)
+ super
+ end
+
+ def add_postamble(src)
+ flush_newline_if_pending(src)
+ src << '@output_buffer.to_s'
+ end
+
+ def flush_newline_if_pending(src)
+ if @newline_pending > 0
+ src << "@output_buffer.safe_append='#{"\n" * @newline_pending}';"
+ @newline_pending = 0
+ end
+ end
+ end
+
+ class ERB
+ # Specify trim mode for the ERB compiler. Defaults to '-'.
+ # See ERB documentation for suitable values.
+ class_attribute :erb_trim_mode
+ self.erb_trim_mode = '-'
+
+ # Default implementation used.
+ class_attribute :erb_implementation
+ self.erb_implementation = Erubis
+
+ # Do not escape templates of these mime types.
+ class_attribute :escape_whitelist
+ self.escape_whitelist = ["text/plain"]
+
+ ENCODING_TAG = Regexp.new("\\A(<%#{ENCODING_FLAG}-?%>)[ \\t]*")
+
+ def self.call(template)
+ new.call(template)
+ end
+
+ def supports_streaming?
+ true
+ end
+
+ def handles_encoding?
+ true
+ end
+
+ def call(template)
+ # First, convert to BINARY, so in case the encoding is
+ # wrong, we can still find an encoding tag
+ # (<%# encoding %>) inside the String using a regular
+ # expression
+ template_source = template.source.dup.force_encoding(Encoding::ASCII_8BIT)
+
+ erb = template_source.gsub(ENCODING_TAG, '')
+ encoding = $2
+
+ erb.force_encoding valid_encoding(template.source.dup, encoding)
+
+ # Always make sure we return a String in the default_internal
+ erb.encode!
+
+ self.class.erb_implementation.new(
+ erb,
+ :escape => (self.class.escape_whitelist.include? template.type),
+ :trim => (self.class.erb_trim_mode == "-")
+ ).src
+ end
+
+ private
+
+ def valid_encoding(string, encoding)
+ # If a magic encoding comment was found, tag the
+ # String with this encoding. This is for a case
+ # where the original String was assumed to be,
+ # for instance, UTF-8, but a magic comment
+ # proved otherwise
+ string.force_encoding(encoding) if encoding
+
+ # If the String is valid, return the encoding we found
+ return string.encoding if string.valid_encoding?
+
+ # Otherwise, raise an exception
+ raise WrongEncodingError.new(string, string.encoding)
+ end
+ end
+ end
+ end
+end
diff --git a/actionview/lib/action_view/template/handlers/raw.rb b/actionview/lib/action_view/template/handlers/raw.rb
new file mode 100644
index 0000000000..0c0d1fffcb
--- /dev/null
+++ b/actionview/lib/action_view/template/handlers/raw.rb
@@ -0,0 +1,11 @@
+module ActionView
+ module Template::Handlers
+ class Raw
+ def call(template)
+ escaped = template.source.gsub(':', '\:')
+
+ '%q:' + escaped + ':;'
+ end
+ end
+ end
+end
diff --git a/actionview/lib/action_view/template/resolver.rb b/actionview/lib/action_view/template/resolver.rb
new file mode 100644
index 0000000000..3304605c1a
--- /dev/null
+++ b/actionview/lib/action_view/template/resolver.rb
@@ -0,0 +1,326 @@
+require "pathname"
+require "active_support/core_ext/class"
+require "active_support/core_ext/class/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 { |x| x.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.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
+
+ extension = pieces.pop
+ unless extension
+ message = "The file #{path} did not specify a template handler. The default is currently ERB, " \
+ "but will change to RAW in the future."
+ ActiveSupport::Deprecation.warn message
+ end
+
+ handler = Template.handler_for_extension(extension)
+ format = pieces.last && Template::Types[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 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,}{.: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
diff --git a/actionview/lib/action_view/template/text.rb b/actionview/lib/action_view/template/text.rb
new file mode 100644
index 0000000000..859c7bc3ce
--- /dev/null
+++ b/actionview/lib/action_view/template/text.rb
@@ -0,0 +1,34 @@
+module ActionView #:nodoc:
+ # = Action View Text Template
+ class Template
+ class Text #:nodoc:
+ attr_accessor :type
+
+ def initialize(string, type = nil)
+ @string = string.to_s
+ @type = Types[type] || type if type
+ @type ||= Types[:text]
+ end
+
+ def identifier
+ 'text template'
+ end
+
+ def inspect
+ 'text template'
+ end
+
+ def to_str
+ @string
+ end
+
+ def render(*args)
+ to_str
+ end
+
+ def formats
+ [@type.to_sym]
+ end
+ end
+ end
+end
diff --git a/actionview/lib/action_view/template/types.rb b/actionview/lib/action_view/template/types.rb
new file mode 100644
index 0000000000..db77cb5d19
--- /dev/null
+++ b/actionview/lib/action_view/template/types.rb
@@ -0,0 +1,57 @@
+require 'set'
+require 'active_support/core_ext/class/attribute_accessors'
+
+module ActionView
+ class Template
+ class Types
+ class Type
+ cattr_accessor :types
+ self.types = Set.new
+
+ def self.register(*t)
+ types.merge(t.map { |type| type.to_s })
+ end
+
+ register :html, :text, :js, :css, :xml, :json
+
+ def self.[](type)
+ return type if type.is_a?(self)
+
+ if type.is_a?(Symbol) || types.member?(type.to_s)
+ new(type)
+ end
+ end
+
+ attr_reader :symbol
+
+ def initialize(symbol)
+ @symbol = symbol.to_sym
+ end
+
+ delegate :to_s, :to_sym, :to => :symbol
+ alias to_str to_s
+
+ def ref
+ to_sym || to_s
+ end
+
+ def ==(type)
+ return false if type.blank?
+ symbol.to_sym == type.to_sym
+ end
+ end
+
+ cattr_accessor :type_klass
+
+ def self.delegate_to(klass)
+ self.type_klass = klass
+ end
+
+ delegate_to Type
+
+ def self.[](type)
+ type_klass[type]
+ end
+ end
+ end
+end