from ast import literal_eval from operator import attrgetter import re from typing import Callable, Iterable, List, Match, NamedTuple, Optional, Tuple, Union from .errors import MarkupError from .style import Style from .text import Span, Text from .emoji import EmojiVariant from ._emoji_replace import _emoji_replace RE_TAGS = re.compile( r"""((\\*)\[([a-z#\/@].*?)\])""", re.VERBOSE, ) RE_HANDLER = re.compile(r"^([\w\.]*?)(\(.*?\))?$") class Tag(NamedTuple): """A tag in console markup.""" name: str """The tag name. e.g. 'bold'.""" parameters: Optional[str] """Any additional parameters after the name.""" def __str__(self) -> str: return ( self.name if self.parameters is None else f"{self.name} {self.parameters}" ) @property def markup(self) -> str: """Get the string representation of this tag.""" return ( f"[{self.name}]" if self.parameters is None else f"[{self.name}={self.parameters}]" ) _ReStringMatch = Match[str] # regex match object _ReSubCallable = Callable[[_ReStringMatch], str] # Callable invoked by re.sub _EscapeSubMethod = Callable[[_ReSubCallable, str], str] # Sub method of a compiled re def escape( markup: str, _escape: _EscapeSubMethod = re.compile(r"(\\*)(\[[a-z#\/@].*?\])").sub ) -> str: """Escapes text so that it won't be interpreted as markup. Args: markup (str): Content to be inserted in to markup. Returns: str: Markup with square brackets escaped. """ def escape_backslashes(match: Match[str]) -> str: """Called by re.sub replace matches.""" backslashes, text = match.groups() return f"{backslashes}{backslashes}\\{text}" markup = _escape(escape_backslashes, markup) return markup def _parse(markup: str) -> Iterable[Tuple[int, Optional[str], Optional[Tag]]]: """Parse markup in to an iterable of tuples of (position, text, tag). Args: markup (str): A string containing console markup """ position = 0 _divmod = divmod _Tag = Tag for match in RE_TAGS.finditer(markup): full_text, escapes, tag_text = match.groups() start, end = match.span() if start > position: yield start, markup[position:start], None if escapes: backslashes, escaped = _divmod(len(escapes), 2) if backslashes: # Literal backslashes yield start, "\\" * backslashes, None start += backslashes * 2 if escaped: # Escape of tag yield start, full_text[len(escapes) :], None position = end continue text, equals, parameters = tag_text.partition("=") yield start, None, _Tag(text, parameters if equals else None) position = end if position < len(markup): yield position, markup[position:], None def render( markup: str, style: Union[str, Style] = "", emoji: bool = True, emoji_variant: Optional[EmojiVariant] = None, ) -> Text: """Render console markup in to a Text instance. Args: markup (str): A string containing console markup. emoji (bool, optional): Also render emoji code. Defaults to True. Raises: MarkupError: If there is a syntax error in the markup. Returns: Text: A test instance. """ emoji_replace = _emoji_replace if "[" not in markup: return Text( emoji_replace(markup, default_variant=emoji_variant) if emoji else markup, style=style, ) text = Text(style=style) append = text.append normalize = Style.normalize style_stack: List[Tuple[int, Tag]] = [] pop = style_stack.pop spans: List[Span] = [] append_span = spans.append _Span = Span _Tag = Tag def pop_style(style_name: str) -> Tuple[int, Tag]: """Pop tag matching given style name.""" for index, (_, tag) in enumerate(reversed(style_stack), 1): if tag.name == style_name: return pop(-index) raise KeyError(style_name) for position, plain_text, tag in _parse(markup): if plain_text is not None: append(emoji_replace(plain_text) if emoji else plain_text) elif tag is not None: if tag.name.startswith("/"): # Closing tag style_name = tag.name[1:].strip() if style_name: # explicit close style_name = normalize(style_name) try: start, open_tag = pop_style(style_name) except KeyError: raise MarkupError( f"closing tag '{tag.markup}' at position {position} doesn't match any open tag" ) from None else: # implicit close try: start, open_tag = pop() except IndexError: raise MarkupError( f"closing tag '[/]' at position {position} has nothing to close" ) from None if open_tag.name.startswith("@"): if open_tag.parameters: handler_name = "" parameters = open_tag.parameters.strip() handler_match = RE_HANDLER.match(parameters) if handler_match is not None: handler_name, match_parameters = handler_match.groups() parameters = ( "()" if match_parameters is None else match_parameters ) try: meta_params = literal_eval(parameters) except SyntaxError as error: raise MarkupError( f"error parsing {parameters!r} in {open_tag.parameters!r}; {error.msg}" ) except Exception as error: raise MarkupError( f"error parsing {open_tag.parameters!r}; {error}" ) from None if handler_name: meta_params = ( handler_name, meta_params if isinstance(meta_params, tuple) else (meta_params,), ) else: meta_params = () append_span( _Span( start, len(text), Style(meta={open_tag.name: meta_params}) ) ) else: append_span(_Span(start, len(text), str(open_tag))) else: # Opening tag normalized_tag = _Tag(normalize(tag.name), tag.parameters) style_stack.append((len(text), normalized_tag)) text_length = len(text) while style_stack: start, tag = style_stack.pop() style = str(tag) if style: append_span(_Span(start, text_length, style)) text.spans = sorted(spans[::-1], key=attrgetter("start")) return text if __name__ == "__main__": # pragma: no cover MARKUP = [ "[red]Hello World[/red]", "[magenta]Hello [b]World[/b]", "[bold]Bold[italic] bold and italic [/bold]italic[/italic]", "Click [link=https://www.willmcgugan.com]here[/link] to visit my Blog", ":warning-emoji: [bold red blink] DANGER![/]", ] from pip._vendor.rich.table import Table from pip._vendor.rich import print grid = Table("Markup", "Result", padding=(0, 1)) for markup in MARKUP: grid.add_row(Text(markup), markup) print(grid)