Viewing file:  markup.py (7.87 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
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)
|