Checkout of Instiki Trunk 1/21/2007.

vendor/rails/actionpack/lib/action_view/compiled_templates.rb

@@ -0,0 +1,70 @@
+
+module ActionView
+
+  # CompiledTemplates modules hold methods that have been compiled.
+  # Templates are compiled into these methods so that they do not need to be
+  # re-read and re-parsed each request.
+  #
+  # Each template may be compiled into one or more methods. Each method accepts a given
+  # set of parameters which is used to implement local assigns passing.
+  #
+  # To use a compiled template module, create a new instance and include it into the class
+  # in which you want the template to be rendered.
+  class CompiledTemplates < Module #:nodoc:
+    attr_reader :method_names
+
+    def initialize
+      @method_names = Hash.new do |hash, key|
+        hash[key] = "__compiled_method_#{(hash.length + 1)}"
+      end
+      @mtimes = {}
+    end
+    
+    # Return the full key for the given identifier and argument names
+    def full_key(identifier, arg_names)
+      [identifier, arg_names]
+    end
+
+    # Return the selector for this method or nil if it has not been compiled
+    def selector(identifier, arg_names)
+      key = full_key(identifier, arg_names)
+      method_names.key?(key) ? method_names[key] : nil
+    end
+    alias :compiled? :selector
+
+    # Return the time at which the method for the given identifier and argument names was compiled.
+    def mtime(identifier, arg_names)
+      @mtimes[full_key(identifier, arg_names)]
+    end
+    
+    # Compile the provided source code for the given argument names and with the given initial line number.
+    # The identifier should be unique to this source.
+    #
+    # The file_name, if provided will appear in backtraces. If not provded, the file_name defaults
+    # to the identifier.
+    #
+    # This method will return the selector for the compiled version of this method.
+    def compile_source(identifier, arg_names, source, initial_line_number = 0, file_name = nil)
+      file_name ||= identifier
+      name = method_names[full_key(identifier, arg_names)]
+      arg_desc = arg_names.empty? ? '' : "(#{arg_names * ', '})"
+      fake_file_name = "#{file_name}#{arg_desc}" # Include the arguments for this version (for now)
+      
+      method_def = wrap_source(name, arg_names, source)
+      
+      begin
+        module_eval(method_def, fake_file_name, initial_line_number)
+        @mtimes[full_key(identifier, arg_names)] = Time.now
+      rescue Object => e
+        e.blame_file! identifier
+        raise
+      end
+      name
+    end
+    
+    # Wrap the provided source in a def ... end block.
+    def wrap_source(name, arg_names, source)
+      "def #{name}(#{arg_names * ', '})\n#{source}\nend"
+    end
+  end
+end