python-peps/docutils/readers/__init__.py

89 lines
2.6 KiB
Python

# Authors: David Goodger; Ueli Schlaepfer
# Contact: goodger@users.sourceforge.net
# Revision: $Revision$
# Date: $Date$
# Copyright: This module has been placed in the public domain.
"""
This package contains Docutils Reader modules.
"""
__docformat__ = 'reStructuredText'
import sys
from docutils import utils, parsers, Component
from docutils.transforms import universal
class Reader(Component):
"""
Abstract base class for docutils Readers.
Each reader module or package must export a subclass also called 'Reader'.
The three steps of a Reader's responsibility are defined: `scan()`,
`parse()`, and `transform()`. Call `read()` to process a document.
"""
component_type = 'reader'
def __init__(self, parser=None, parser_name='restructuredtext'):
"""
Initialize the Reader instance.
Several instance attributes are defined with dummy initial values.
Subclasses may use these attributes as they wish.
"""
self.parser = parser
"""A `parsers.Parser` instance shared by all doctrees. May be left
unspecified if the document source determines the parser."""
if parser is None and parser_name:
self.set_parser(parser_name)
self.source = None
"""`docutils.io` IO object, source of input data."""
self.input = None
"""Raw text input; either a single string or, for more complex cases,
a collection of strings."""
def set_parser(self, parser_name):
"""Set `self.parser` by name."""
parser_class = parsers.get_parser_class(parser_name)
self.parser = parser_class()
def read(self, source, parser, settings):
self.source = source
if not self.parser:
self.parser = parser
self.settings = settings
self.input = self.source.read()
self.parse()
return self.document
def parse(self):
"""Parse `self.input` into a document tree."""
self.document = document = self.new_document()
self.parser.parse(self.input, document)
document.current_source = document.current_line = None
def new_document(self):
"""Create and return a new empty document tree (root node)."""
document = utils.new_document(self.source.source_path, self.settings)
return document
_reader_aliases = {}
def get_reader_class(reader_name):
"""Return the Reader class from the `reader_name` module."""
reader_name = reader_name.lower()
if _reader_aliases.has_key(reader_name):
reader_name = _reader_aliases[reader_name]
module = __import__(reader_name, globals(), locals())
return module.Reader