path: root/src/markupsafe/__init__.py

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 &lt;em&gt;World&lt;/em&gt;!')

    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 &amp; bar</em>')
    >>> Markup("<em>Hello</em> ") + "<foo>"
    Markup('<em>Hello</em> &lt;foo&gt;')
    """

    __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 &raquo; <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 &raquo;\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