How to implement custom plugin

[Paillat-dev]

I am trying to implement a plugin that matches the discord spoiler syntax (|| for opening and closing, both inline and multiline) but I am struggling to understand how to do it and not really familiar with how to.

Anyone could help ?

[lepture]

You can read source code https://github.com/lepture/mistune/blob/master/src/mistune/plugins/spoiler.py

You also can ask me to create a custom mistune plugin or directive for your needs with GitHub sponsor one time tier (Mistune enhance)

[Paillat-dev]

Thank you, I ended up doing it inspired from the strike trough plugin. Ill share my code in another comment for future reference.

[Paillat-dev]

import mistune
from mistune.plugins.formatting import strikethrough
from mistune.util import escape, safe_entity
from typing_extensions import override

if TYPE_CHECKING:
    from mistune.core import BaseRenderer, InlineState
    from mistune.inline_parser import InlineParser
    from mistune.markdown import Markdown

from typing import Any

from mistune.helpers import PREVENT_BACKSLASH
from mistune.plugins.formatting import _parse_to_end  # pyright: ignore[reportPrivateUsage,reportUnknownVariableType]

_SPOILER_END = re.compile(r"(?:" + PREVENT_BACKSLASH + r"\\\||[^\s\|])\|\|(?!\|)")


def parse_spoiler(inline: "InlineParser", m: Match[str], state: "InlineState") -> int | None:
    return _parse_to_end(inline, m, state, "spoiler", _SPOILER_END) # pyright: ignore[reportUnknownVariableType]


def render_spoiler(renderer: "BaseRenderer", text: str) -> str:  # noqa: ARG001 # pyright: ignore[reportUnusedParameter]
    return "<discord-spoiler>" + text + "</discord-spoiler>"


def spoiler(md: "Markdown") -> None:
    """Add a mistune plugin to support spoiler tags. Similar to strikethrough but uses different syntax."""
    md.inline.register(
        "spoiler",
        r"\|\|(?=[^\s\|])",
        parse_spoiler,
        before="link",
    )
    if md.renderer and md.renderer.NAME == "html":
        md.renderer.register("spoiler", render_spoiler)