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Diffstat (limited to 'actionpack/lib/action_view/template.rb')
| -rw-r--r-- | actionpack/lib/action_view/template.rb | 340 |
1 files changed, 0 insertions, 340 deletions
diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb deleted file mode 100644 index c25b1efc2b..0000000000 --- a/actionpack/lib/action_view/template.rb +++ /dev/null @@ -1,340 +0,0 @@ -require 'active_support/core_ext/object/try' -require 'active_support/core_ext/kernel/singleton_class' -require 'thread' - -module ActionView - # = Action View Template - class Template - extend ActiveSupport::Autoload - - # === Encodings in ActionView::Template - # - # ActionView::Template is one of a few sources of potential - # encoding issues in Rails. This is because the source for - # templates are usually read from disk, and Ruby (like most - # encoding-aware programming languages) assumes that the - # String retrieved through File IO is encoded in the - # <tt>default_external</tt> encoding. In Rails, the default - # <tt>default_external</tt> encoding is UTF-8. - # - # As a result, if a user saves their template as ISO-8859-1 - # (for instance, using a non-Unicode-aware text editor), - # and uses characters outside of the ASCII range, their - # users will see diamonds with question marks in them in - # the browser. - # - # For the rest of this documentation, when we say "UTF-8", - # we mean "UTF-8 or whatever the default_internal encoding - # is set to". By default, it will be UTF-8. - # - # To mitigate this problem, we use a few strategies: - # 1. If the source is not valid UTF-8, we raise an exception - # when the template is compiled to alert the user - # to the problem. - # 2. The user can specify the encoding using Ruby-style - # encoding comments in any template engine. If such - # a comment is supplied, Rails will apply that encoding - # to the resulting compiled source returned by the - # template handler. - # 3. In all cases, we transcode the resulting String to - # the UTF-8. - # - # This means that other parts of Rails can always assume - # that templates are encoded in UTF-8, even if the original - # source of the template was not UTF-8. - # - # From a user's perspective, the easiest thing to do is - # to save your templates as UTF-8. If you do this, you - # do not need to do anything else for things to "just work". - # - # === Instructions for template handlers - # - # The easiest thing for you to do is to simply ignore - # encodings. Rails will hand you the template source - # as the default_internal (generally UTF-8), raising - # an exception for the user before sending the template - # to you if it could not determine the original encoding. - # - # For the greatest simplicity, you can support only - # UTF-8 as the <tt>default_internal</tt>. This means - # that from the perspective of your handler, the - # entire pipeline is just UTF-8. - # - # === Advanced: Handlers with alternate metadata sources - # - # If you want to provide an alternate mechanism for - # specifying encodings (like ERB does via <%# encoding: ... %>), - # you may indicate that you will handle encodings yourself - # by implementing <tt>self.handles_encoding?</tt> - # on your handler. - # - # If you do, Rails will not try to encode the String - # into the default_internal, passing you the unaltered - # bytes tagged with the assumed encoding (from - # default_external). - # - # In this case, make sure you return a String from - # your handler encoded in the default_internal. Since - # you are handling out-of-band metadata, you are - # also responsible for alerting the user to any - # problems with converting the user's data to - # the <tt>default_internal</tt>. - # - # To do so, simply raise +WrongEncodingError+ as follows: - # - # raise WrongEncodingError.new( - # problematic_string, - # expected_encoding - # ) - - eager_autoload do - autoload :Error - autoload :Handlers - autoload :Text - autoload :Types - end - - extend Template::Handlers - - attr_accessor :locals, :formats, :virtual_path - - attr_reader :source, :identifier, :handler, :original_encoding, :updated_at - - # This finalizer is needed (and exactly with a proc inside another proc) - # otherwise templates leak in development. - Finalizer = proc do |method_name, mod| - proc do - mod.module_eval do - remove_possible_method method_name - end - end - end - - def initialize(source, identifier, handler, details) - format = details[:format] || (handler.default_format if handler.respond_to?(:default_format)) - - @source = source - @identifier = identifier - @handler = handler - @compiled = false - @original_encoding = nil - @locals = details[:locals] || [] - @virtual_path = details[:virtual_path] - @updated_at = details[:updated_at] || Time.now - @formats = Array(format).map { |f| f.respond_to?(:ref) ? f.ref : f } - @compile_mutex = Mutex.new - end - - # Returns if the underlying handler supports streaming. If so, - # a streaming buffer *may* be passed when it start rendering. - def supports_streaming? - handler.respond_to?(:supports_streaming?) && handler.supports_streaming? - end - - # Render a template. If the template was not compiled yet, it is done - # exactly before rendering. - # - # This method is instrumented as "!render_template.action_view". Notice that - # we use a bang in this instrumentation because you don't want to - # consume this in production. This is only slow if it's being listened to. - def render(view, locals, buffer=nil, &block) - instrument("!render_template") do - compile!(view) - view.send(method_name, locals, buffer, &block) - end - rescue Exception => e - handle_render_error(view, e) - end - - def type - @type ||= Types[@formats.first] if @formats.first - end - - # Receives a view object and return a template similar to self by using @virtual_path. - # - # This method is useful if you have a template object but it does not contain its source - # anymore since it was already compiled. In such cases, all you need to do is to call - # refresh passing in the view object. - # - # Notice this method raises an error if the template to be refreshed does not have a - # virtual path set (true just for inline templates). - def refresh(view) - raise "A template needs to have a virtual path in order to be refreshed" unless @virtual_path - lookup = view.lookup_context - pieces = @virtual_path.split("/") - name = pieces.pop - partial = !!name.sub!(/^_/, "") - lookup.disable_cache do - lookup.find_template(name, [ pieces.join('/') ], partial, @locals) - end - end - - def inspect - @inspect ||= defined?(Rails.root) ? identifier.sub("#{Rails.root}/", '') : identifier - end - - # This method is responsible for properly setting the encoding of the - # source. Until this point, we assume that the source is BINARY data. - # If no additional information is supplied, we assume the encoding is - # the same as <tt>Encoding.default_external</tt>. - # - # The user can also specify the encoding via a comment on the first - # line of the template (# encoding: NAME-OF-ENCODING). This will work - # with any template engine, as we process out the encoding comment - # before passing the source on to the template engine, leaving a - # blank line in its stead. - def encode! - return unless source.encoding == Encoding::BINARY - - # Look for # encoding: *. If we find one, we'll encode the - # String in that encoding, otherwise, we'll use the - # default external encoding. - if source.sub!(/\A#{ENCODING_FLAG}/, '') - encoding = magic_encoding = $1 - else - encoding = Encoding.default_external - end - - # Tag the source with the default external encoding - # or the encoding specified in the file - source.force_encoding(encoding) - - # If the user didn't specify an encoding, and the handler - # handles encodings, we simply pass the String as is to - # the handler (with the default_external tag) - if !magic_encoding && @handler.respond_to?(:handles_encoding?) && @handler.handles_encoding? - source - # Otherwise, if the String is valid in the encoding, - # encode immediately to default_internal. This means - # that if a handler doesn't handle encodings, it will - # always get Strings in the default_internal - elsif source.valid_encoding? - source.encode! - # Otherwise, since the String is invalid in the encoding - # specified, raise an exception - else - raise WrongEncodingError.new(source, encoding) - end - end - - protected - - # Compile a template. This method ensures a template is compiled - # just once and removes the source after it is compiled. - def compile!(view) #:nodoc: - return if @compiled - - # Templates can be used concurrently in threaded environments - # so compilation and any instance variable modification must - # be synchronized - @compile_mutex.synchronize do - # Any thread holding this lock will be compiling the template needed - # by the threads waiting. So re-check the @compiled flag to avoid - # re-compilation - return if @compiled - - if view.is_a?(ActionView::CompiledTemplates) - mod = ActionView::CompiledTemplates - else - mod = view.singleton_class - end - - instrument("!compile_template") do - compile(view, mod) - end - - # Just discard the source if we have a virtual path. This - # means we can get the template back. - @source = nil if @virtual_path - @compiled = true - end - end - - # Among other things, this method is responsible for properly setting - # the encoding of the compiled template. - # - # If the template engine handles encodings, we send the encoded - # String to the engine without further processing. This allows - # the template engine to support additional mechanisms for - # specifying the encoding. For instance, ERB supports <%# encoding: %> - # - # Otherwise, after we figure out the correct encoding, we then - # encode the source into <tt>Encoding.default_internal</tt>. - # In general, this means that templates will be UTF-8 inside of Rails, - # regardless of the original source encoding. - def compile(view, mod) #:nodoc: - encode! - method_name = self.method_name - code = @handler.call(self) - - # Make sure that the resulting String to be evalled is in the - # encoding of the code - source = <<-end_src - def #{method_name}(local_assigns, output_buffer) - _old_virtual_path, @virtual_path = @virtual_path, #{@virtual_path.inspect};_old_output_buffer = @output_buffer;#{locals_code};#{code} - ensure - @virtual_path, @output_buffer = _old_virtual_path, _old_output_buffer - end - end_src - - # Make sure the source is in the encoding of the returned code - source.force_encoding(code.encoding) - - # In case we get back a String from a handler that is not in - # BINARY or the default_internal, encode it to the default_internal - source.encode! - - # Now, validate that the source we got back from the template - # handler is valid in the default_internal. This is for handlers - # that handle encoding but screw up - unless source.valid_encoding? - raise WrongEncodingError.new(@source, Encoding.default_internal) - end - - begin - mod.module_eval(source, identifier, 0) - ObjectSpace.define_finalizer(self, Finalizer[method_name, mod]) - rescue Exception => e # errors from template code - if logger = (view && view.logger) - logger.debug "ERROR: compiling #{method_name} RAISED #{e}" - logger.debug "Function body: #{source}" - logger.debug "Backtrace: #{e.backtrace.join("\n")}" - end - - raise ActionView::Template::Error.new(self, e) - end - end - - def handle_render_error(view, e) #:nodoc: - if e.is_a?(Template::Error) - e.sub_template_of(self) - raise e - else - template = self - unless template.source - template = refresh(view) - template.encode! - end - raise Template::Error.new(template, e) - end - end - - def locals_code #:nodoc: - # Double assign to suppress the dreaded 'assigned but unused variable' warning - @locals.map { |key| "#{key} = #{key} = local_assigns[:#{key}];" }.join - end - - def method_name #:nodoc: - @method_name ||= "_#{identifier_method_name}__#{@identifier.hash}_#{__id__}".gsub('-', "_") - end - - def identifier_method_name #:nodoc: - inspect.gsub(/[^a-z_]/, '_') - end - - def instrument(action, &block) - payload = { virtual_path: @virtual_path, identifier: @identifier } - ActiveSupport::Notifications.instrument("#{action}.action_view", payload, &block) - end - end -end |