view sat/tools/common/regex.py @ 3983:31c3d6652115

component AP gateway: ignore actor delection notifications: When a `Delete` activity was received and the object was the emitting actor itself, the signature checking was failing if the actor was unknown (due to the impossibility to retrieve the actor public key, as it is no more accessible). To avoid that, those notifications are ignored for now. In the future they should clean the cache linked to this actor.
author Goffi <goffi@goffi.org>
date Tue, 15 Nov 2022 18:15:16 +0100
parents 85b8a899f407
children 524856bd7b19
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#!/usr/bin/env python3


# Salut à Toi: an XMPP client
# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed 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
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

""" regex tools common to backend and frontends """

import re
import unicodedata

path_escape = {"%": "%25", "/": "%2F", "\\": "%5c"}
path_escape_rev = {re.escape(v): k for k, v in path_escape.items()}
path_escape = {re.escape(k): v for k, v in path_escape.items()}
#  thanks to Martijn Pieters (https://stackoverflow.com/a/14693789)
RE_ANSI_REMOVE = re.compile(r'\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])')
RE_TEXT_URL = re.compile(r'[^a-zA-Z0-9,_]+')
TEXT_MAX_LEN = 60
# min lenght is currently deactivated
TEXT_WORD_MIN_LENGHT = 0


def reJoin(exps):
    """Join (OR) various regexes"""
    return re.compile("|".join(exps))


def reSubDict(pattern, repl_dict, string):
    """Replace key, value found in dict according to pattern

    @param pattern(basestr): pattern using keys found in repl_dict
    @repl_dict(dict): keys found in this dict will be replaced by
        corresponding values
    @param string(basestr): string to use for the replacement
    """
    return pattern.sub(lambda m: repl_dict[re.escape(m.group(0))], string)


path_escape_re = reJoin(list(path_escape.keys()))
path_escape_rev_re = reJoin(list(path_escape_rev.keys()))


def pathEscape(string):
    """Escape string so it can be use in a file path

    @param string(basestr): string to escape
    @return (str, unicode): escaped string, usable in a file path
    """
    return reSubDict(path_escape_re, path_escape, string)


def pathUnescape(string):
    """Unescape string from value found in file path

    @param string(basestr): string found in file path
    @return (str, unicode): unescaped string
    """
    return reSubDict(path_escape_rev_re, path_escape_rev, string)


def ansiRemove(string):
    """Remove ANSI escape codes from string

    @param string(basestr): string to filter
    @return (str, unicode): string without ANSI escape codes
    """
    return RE_ANSI_REMOVE.sub("", string)


def urlFriendlyText(text):
    """Convert text to url-friendly one"""
    # we change special chars to ascii one,
    # trick found at https://stackoverflow.com/a/3194567
    text = unicodedata.normalize('NFD', text).encode('ascii', 'ignore').decode('utf-8')
    text = RE_TEXT_URL.sub(' ', text).lower()
    text = '-'.join([t for t in text.split() if t and len(t)>=TEXT_WORD_MIN_LENGHT])
    while len(text) > TEXT_MAX_LEN:
        if '-' in text:
            text = text.rsplit('-', 1)[0]
        else:
            text = text[:TEXT_MAX_LEN]
    return text