module ActionView
# CompiledTemplates modules hold methods that have been compiled.
# Templates are compiled into these methods so that they do not need to be
# read and parsed for 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
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 provided, 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 Exception => e # errors from compiled source
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
