1# Python Markdown
2
3# A Python implementation of John Gruber's Markdown.
4
5# Documentation: https://python-markdown.github.io/
6# GitHub: https://github.com/Python-Markdown/markdown/
7# PyPI: https://pypi.org/project/Markdown/
8
9# Started by Manfred Stienstra (http://www.dwerg.net/).
10# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
11# Currently maintained by Waylan Limberg (https://github.com/waylan),
12# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
13
14# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
15# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
16# Copyright 2004 Manfred Stienstra (the original version)
17
18# License: BSD (see LICENSE.md for details).
19
20"""
21Markdown accepts an [`Extension`][markdown.extensions.Extension] instance for each extension. Therefore, each extension
22must to define a class that extends [`Extension`][markdown.extensions.Extension] and over-rides the
23[`extendMarkdown`][markdown.extensions.Extension.extendMarkdown] method. Within this class one can manage configuration
24options for their extension and attach the various processors and patterns which make up an extension to the
25[`Markdown`][markdown.Markdown] instance.
26"""
27
28from __future__ import annotations
29
30from typing import TYPE_CHECKING, Any, Iterable, Mapping
31from ..util import parseBoolValue
32
33if TYPE_CHECKING: # pragma: no cover
34 from markdown import Markdown
35
36
37class Extension:
38 """ Base class for extensions to subclass. """
39
40 config: Mapping[str, list] = {}
41 """
42 Default configuration for an extension.
43
44 This attribute is to be defined in a subclass and must be of the following format:
45
46 ``` python
47 config = {
48 'key': ['value', 'description']
49 }
50 ```
51
52 Note that [`setConfig`][markdown.extensions.Extension.setConfig] will raise a [`KeyError`][]
53 if a default is not set for each option.
54 """
55
56 def __init__(self, **kwargs):
57 """ Initiate Extension and set up configs. """
58 self.setConfigs(kwargs)
59
60 def getConfig(self, key: str, default: Any = '') -> Any:
61 """
62 Return a single configuration option value.
63
64 Arguments:
65 key: The configuration option name.
66 default: Default value to return if key is not set.
67
68 Returns:
69 Value of stored configuration option.
70 """
71 if key in self.config:
72 return self.config[key][0]
73 else:
74 return default
75
76 def getConfigs(self) -> dict[str, Any]:
77 """
78 Return all configuration options.
79
80 Returns:
81 All configuration options.
82 """
83 return {key: self.getConfig(key) for key in self.config.keys()}
84
85 def getConfigInfo(self) -> list[tuple[str, str]]:
86 """
87 Return descriptions of all configuration options.
88
89 Returns:
90 All descriptions of configuration options.
91 """
92 return [(key, self.config[key][1]) for key in self.config.keys()]
93
94 def setConfig(self, key: str, value: Any) -> None:
95 """
96 Set a configuration option.
97
98 If the corresponding default value set in [`config`][markdown.extensions.Extension.config]
99 is a `bool` value or `None`, then `value` is passed through
100 [`parseBoolValue`][markdown.util.parseBoolValue] before being stored.
101
102 Arguments:
103 key: Name of configuration option to set.
104 value: Value to assign to option.
105
106 Raises:
107 KeyError: If `key` is not known.
108 """
109 if isinstance(self.config[key][0], bool):
110 value = parseBoolValue(value)
111 if self.config[key][0] is None:
112 value = parseBoolValue(value, preserve_none=True)
113 self.config[key][0] = value
114
115 def setConfigs(self, items: Mapping[str, Any] | Iterable[tuple[str, Any]]) -> None:
116 """
117 Loop through a collection of configuration options, passing each to
118 [`setConfig`][markdown.extensions.Extension.setConfig].
119
120 Arguments:
121 items: Collection of configuration options.
122
123 Raises:
124 KeyError: for any unknown key.
125 """
126 if hasattr(items, 'items'):
127 # it's a dict
128 items = items.items()
129 for key, value in items:
130 self.setConfig(key, value)
131
132 def extendMarkdown(self, md: Markdown) -> None:
133 """
134 Add the various processors and patterns to the Markdown Instance.
135
136 This method must be overridden by every extension.
137
138 Arguments:
139 md: The Markdown instance.
140
141 """
142 raise NotImplementedError(
143 'Extension "%s.%s" must define an "extendMarkdown"'
144 'method.' % (self.__class__.__module__, self.__class__.__name__)
145 )