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Diffstat (limited to 'src/markupsafe/__init__.py')
| -rw-r--r-- | src/markupsafe/__init__.py | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/src/markupsafe/__init__.py b/src/markupsafe/__init__.py new file mode 100644 index 0000000..7166b19 --- /dev/null +++ b/src/markupsafe/__init__.py @@ -0,0 +1,295 @@ +import functools +import re +import string +import typing as t + +if t.TYPE_CHECKING: + import typing_extensions as te + + class HasHTML(te.Protocol): + def __html__(self) -> str: + pass + + +__version__ = "2.1.2" + +_strip_comments_re = re.compile(r"<!--.*?-->", re.DOTALL) +_strip_tags_re = re.compile(r"<.*?>", re.DOTALL) + + +def _simple_escaping_wrapper(name: str) -> t.Callable[..., "Markup"]: + orig = getattr(str, name) + + @functools.wraps(orig) + def wrapped(self: "Markup", *args: t.Any, **kwargs: t.Any) -> "Markup": + args = _escape_argspec(list(args), enumerate(args), self.escape) # type: ignore + _escape_argspec(kwargs, kwargs.items(), self.escape) + return self.__class__(orig(self, *args, **kwargs)) + + return wrapped + + +class Markup(str): + """A string that is ready to be safely inserted into an HTML or XML + document, either because it was escaped or because it was marked + safe. + + Passing an object to the constructor converts it to text and wraps + it to mark it safe without escaping. To escape the text, use the + :meth:`escape` class method instead. + + >>> Markup("Hello, <em>World</em>!") + Markup('Hello, <em>World</em>!') + >>> Markup(42) + Markup('42') + >>> Markup.escape("Hello, <em>World</em>!") + Markup('Hello <em>World</em>!') + + This implements the ``__html__()`` interface that some frameworks + use. Passing an object that implements ``__html__()`` will wrap the + output of that method, marking it safe. + + >>> class Foo: + ... def __html__(self): + ... return '<a href="/foo">foo</a>' + ... + >>> Markup(Foo()) + Markup('<a href="/foo">foo</a>') + + This is a subclass of :class:`str`. It has the same methods, but + escapes their arguments and returns a ``Markup`` instance. + + >>> Markup("<em>%s</em>") % ("foo & bar",) + Markup('<em>foo & bar</em>') + >>> Markup("<em>Hello</em> ") + "<foo>" + Markup('<em>Hello</em> <foo>') + """ + + __slots__ = () + + def __new__( + cls, base: t.Any = "", encoding: t.Optional[str] = None, errors: str = "strict" + ) -> "Markup": + if hasattr(base, "__html__"): + base = base.__html__() + + if encoding is None: + return super().__new__(cls, base) + + return super().__new__(cls, base, encoding, errors) + + def __html__(self) -> "Markup": + return self + + def __add__(self, other: t.Union[str, "HasHTML"]) -> "Markup": + if isinstance(other, str) or hasattr(other, "__html__"): + return self.__class__(super().__add__(self.escape(other))) + + return NotImplemented + + def __radd__(self, other: t.Union[str, "HasHTML"]) -> "Markup": + if isinstance(other, str) or hasattr(other, "__html__"): + return self.escape(other).__add__(self) + + return NotImplemented + + def __mul__(self, num: "te.SupportsIndex") -> "Markup": + if isinstance(num, int): + return self.__class__(super().__mul__(num)) + + return NotImplemented + + __rmul__ = __mul__ + + def __mod__(self, arg: t.Any) -> "Markup": + if isinstance(arg, tuple): + # a tuple of arguments, each wrapped + arg = tuple(_MarkupEscapeHelper(x, self.escape) for x in arg) + elif hasattr(type(arg), "__getitem__") and not isinstance(arg, str): + # a mapping of arguments, wrapped + arg = _MarkupEscapeHelper(arg, self.escape) + else: + # a single argument, wrapped with the helper and a tuple + arg = (_MarkupEscapeHelper(arg, self.escape),) + + return self.__class__(super().__mod__(arg)) + + def __repr__(self) -> str: + return f"{self.__class__.__name__}({super().__repr__()})" + + def join(self, seq: t.Iterable[t.Union[str, "HasHTML"]]) -> "Markup": + return self.__class__(super().join(map(self.escape, seq))) + + join.__doc__ = str.join.__doc__ + + def split( # type: ignore + self, sep: t.Optional[str] = None, maxsplit: int = -1 + ) -> t.List["Markup"]: + return [self.__class__(v) for v in super().split(sep, maxsplit)] + + split.__doc__ = str.split.__doc__ + + def rsplit( # type: ignore + self, sep: t.Optional[str] = None, maxsplit: int = -1 + ) -> t.List["Markup"]: + return [self.__class__(v) for v in super().rsplit(sep, maxsplit)] + + rsplit.__doc__ = str.rsplit.__doc__ + + def splitlines(self, keepends: bool = False) -> t.List["Markup"]: # type: ignore + return [self.__class__(v) for v in super().splitlines(keepends)] + + splitlines.__doc__ = str.splitlines.__doc__ + + def unescape(self) -> str: + """Convert escaped markup back into a text string. This replaces + HTML entities with the characters they represent. + + >>> Markup("Main » <em>About</em>").unescape() + 'Main » <em>About</em>' + """ + from html import unescape + + return unescape(str(self)) + + def striptags(self) -> str: + """:meth:`unescape` the markup, remove tags, and normalize + whitespace to single spaces. + + >>> Markup("Main »\t<em>About</em>").striptags() + 'Main » About' + """ + # Use two regexes to avoid ambiguous matches. + value = _strip_comments_re.sub("", self) + value = _strip_tags_re.sub("", value) + value = " ".join(value.split()) + return Markup(value).unescape() + + @classmethod + def escape(cls, s: t.Any) -> "Markup": + """Escape a string. Calls :func:`escape` and ensures that for + subclasses the correct type is returned. + """ + rv = escape(s) + + if rv.__class__ is not cls: + return cls(rv) + + return rv + + for method in ( + "__getitem__", + "capitalize", + "title", + "lower", + "upper", + "replace", + "ljust", + "rjust", + "lstrip", + "rstrip", + "center", + "strip", + "translate", + "expandtabs", + "swapcase", + "zfill", + ): + locals()[method] = _simple_escaping_wrapper(method) + + del method + + def partition(self, sep: str) -> t.Tuple["Markup", "Markup", "Markup"]: + l, s, r = super().partition(self.escape(sep)) + cls = self.__class__ + return cls(l), cls(s), cls(r) + + def rpartition(self, sep: str) -> t.Tuple["Markup", "Markup", "Markup"]: + l, s, r = super().rpartition(self.escape(sep)) + cls = self.__class__ + return cls(l), cls(s), cls(r) + + def format(self, *args: t.Any, **kwargs: t.Any) -> "Markup": + formatter = EscapeFormatter(self.escape) + return self.__class__(formatter.vformat(self, args, kwargs)) + + def __html_format__(self, format_spec: str) -> "Markup": + if format_spec: + raise ValueError("Unsupported format specification for Markup.") + + return self + + +class EscapeFormatter(string.Formatter): + __slots__ = ("escape",) + + def __init__(self, escape: t.Callable[[t.Any], Markup]) -> None: + self.escape = escape + super().__init__() + + def format_field(self, value: t.Any, format_spec: str) -> str: + if hasattr(value, "__html_format__"): + rv = value.__html_format__(format_spec) + elif hasattr(value, "__html__"): + if format_spec: + raise ValueError( + f"Format specifier {format_spec} given, but {type(value)} does not" + " define __html_format__. A class that defines __html__ must define" + " __html_format__ to work with format specifiers." + ) + rv = value.__html__() + else: + # We need to make sure the format spec is str here as + # otherwise the wrong callback methods are invoked. + rv = string.Formatter.format_field(self, value, str(format_spec)) + return str(self.escape(rv)) + + +_ListOrDict = t.TypeVar("_ListOrDict", list, dict) + + +def _escape_argspec( + obj: _ListOrDict, iterable: t.Iterable[t.Any], escape: t.Callable[[t.Any], Markup] +) -> _ListOrDict: + """Helper for various string-wrapped functions.""" + for key, value in iterable: + if isinstance(value, str) or hasattr(value, "__html__"): + obj[key] = escape(value) + + return obj + + +class _MarkupEscapeHelper: + """Helper for :meth:`Markup.__mod__`.""" + + __slots__ = ("obj", "escape") + + def __init__(self, obj: t.Any, escape: t.Callable[[t.Any], Markup]) -> None: + self.obj = obj + self.escape = escape + + def __getitem__(self, item: t.Any) -> "_MarkupEscapeHelper": + return _MarkupEscapeHelper(self.obj[item], self.escape) + + def __str__(self) -> str: + return str(self.escape(self.obj)) + + def __repr__(self) -> str: + return str(self.escape(repr(self.obj))) + + def __int__(self) -> int: + return int(self.obj) + + def __float__(self) -> float: + return float(self.obj) + + +# circular import +try: + from ._speedups import escape as escape + from ._speedups import escape_silent as escape_silent + from ._speedups import soft_str as soft_str +except ImportError: + from ._native import escape as escape + from ._native import escape_silent as escape_silent # noqa: F401 + from ._native import soft_str as soft_str # noqa: F401 |