Source code for univention.directory.reports.parser

# -*- coding: utf-8 -*-
#
# Univention Directory Reports
#  splits a text into tokens
#
# Copyright 2007-2020 Univention GmbH
#
# https://www.univention.de/
#
# All rights reserved.
#
# The source code of this program is made available
# under the terms of the GNU Affero General Public License version 3
# (GNU AGPL V3) as published by the Free Software Foundation.
#
# Binary versions of this program provided by Univention to you as
# well as other copyrighted, protected or trademarked materials like
# Logos, graphics, fonts, specific documentations and configurations,
# cryptographic keys etc. are subject to a license agreement between
# you and Univention and not subject to the GNU AGPL V3.
#
# In the case you use this program under the terms of the GNU AGPL V3,
# the program is provided in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public
# License with the Debian GNU/Linux or Univention distribution in file
# /usr/share/common-licenses/AGPL-3; if not, see
# <https://www.gnu.org/licenses/>.

import re
import shlex

from .tokens import Token, TextToken, AttributeToken, PolicyToken, QueryToken, HeaderToken, FooterToken, IContextToken, ResolveToken, DateToken


[docs]class Parser(object): REGEX_OPEN = re.compile('<@(?P<tag>[^/][^ ]+)( +(?P<attrs>([a-z-0-9]+="[^"]*" *)*)|)@>') REGEX_CLOSE = re.compile('<@/(?P<tag>[^ ]+) *@>') START = '<@' END = '@>' def __init__(self, filename=None, data=None): if filename: self._filename = filename fd = open(self._filename, 'r') self._data = fd.read() fd.close() elif data: self._data = data self._tokens = [] self._header = None self._footer = None self._context = self._tokens self._stack = [self._tokens]
[docs] def parse_token(self, token): attrs = {} closing = False m = Parser.REGEX_OPEN.match(token) if not m: m = Parser.REGEX_CLOSE.match(token) if not m: raise SyntaxError("failed to parse token: '%s'" % token) closing = True d = m.groupdict() if not closing and d.get('attrs', None): for attr in shlex.split(d['attrs']): key, value = attr.split('=', 1) attrs[key] = value return (d['tag'], attrs, closing)
[docs] def next_token(self): if not self._data: # empty token return Token() start = self._data.find(Parser.START) # no further tags -> rest is text if start < 0: token = TextToken(self._data) self._data = None return token # is text before next tag? if start > 0: token = TextToken(self._data[: start]) self._data = self._data[start:] return token # find end of tag end = self._data.find(Parser.END) if end < 0: max_len = len(self._data) - start raise SyntaxError('No matching end tag (tag: %s)' % self._data[start: min(20, max_len)]) name, attrs, closing = self.parse_token(self._data[start: end + len(Parser.END)]) self._data = self._data[end + len(Parser.END):] if name == 'attribute': return AttributeToken(attrs) elif name == 'policy': return PolicyToken(attrs) elif name == 'query': return QueryToken(attrs, closing) elif name == 'resolve': return ResolveToken(attrs, closing) elif name == 'header': return HeaderToken(attrs, closing) elif name == 'footer': return FooterToken(attrs, closing) elif name == 'date': return DateToken(attrs) else: raise SyntaxError('Unknown tag: %s' % name)
[docs] def tokenize(self): token = self.next_token() while token: if isinstance(token, (TextToken, AttributeToken, PolicyToken, DateToken)): if isinstance(token, TextToken): if token.data == '\n' and len(self._context) and isinstance(self._context[-1], HeaderToken): # ignore line feed after header pass else: self._context.append(token) else: self._context.append(token) elif isinstance(token, IContextToken): if not token.closing: self._stack.append(self._context) self._context.append(token) self._context = self._context[-1] else: self._context[-1].closing = True self._context = self._stack.pop() token = self.next_token() # strip header and footer, if exist trash = [] for i in range(len(self._context)): if isinstance(self._context[i], HeaderToken): self._header = self._context[i] if len(self._header) and isinstance(self._header[0], TextToken): self._header = self._header[0] trash.append(i) elif isinstance(self._context[i], FooterToken): self._footer = self._context[i] if len(self._footer) and isinstance(self._footer[0], TextToken): self._footer = self._footer[0] if i > 0 and isinstance(self._context[i - 1], TextToken) and \ self._context[i - 1].data == '\n': trash.append(i - 1) trash.append(i) trash.reverse() for rm in trash: self._context.pop(rm)