Markdown improvements

CHANGELOG.md

@@ -7,6 +7,17 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
+### Fixed
+
+- Fixed indented code blocks not showing up in `Markdown` https://github.com/Textualize/textual/issues/2781
+- Fixed inline code blocks in lists showing out of order in `Markdown` https://github.com/Textualize/textual/issues/2676
+- Fixed list items in a `Markdown` being added to the focus chain https://github.com/Textualize/textual/issues/2380
+
+### Added
+
+- Added a method of allowing third party code to handle unhandled tokens in `Markdown` https://github.com/Textualize/textual/pull/2803
+- Added `MarkdownBlock` as an exported symbol in `textual.widgets.markdown` https://github.com/Textualize/textual/pull/2803
+
 ### Changed
 
 - Tooltips are now inherited, so will work with compound widgets

src/textual/widgets/_markdown.py

@@ -4,6 +4,7 @@
 from typing import Callable, Iterable
 
 from markdown_it import MarkdownIt
+from markdown_it.token import Token
 from rich import box
 from rich.style import Style
 from rich.syntax import Syntax
@@ -12,7 +13,7 @@
 from typing_extensions import TypeAlias
 
 from ..app import ComposeResult
-from ..containers import Horizontal, VerticalScroll
+from ..containers import Horizontal, Vertical, VerticalScroll
 from ..events import Mount
 from ..message import Message
 from ..reactive import reactive, var
@@ -269,7 +270,7 @@ class MarkdownBulletList(MarkdownList):
         width: 1fr;
     }
 
-    MarkdownBulletList VerticalScroll {
+    MarkdownBulletList Vertical {
         height: auto;
         width: 1fr;
     }
@@ -280,7 +281,7 @@ def compose(self) -> ComposeResult:
             if isinstance(block, MarkdownListItem):
                 bullet = MarkdownBullet()
                 bullet.symbol = block.bullet
-                yield Horizontal(bullet, VerticalScroll(*block._blocks))
+                yield Horizontal(bullet, Vertical(*block._blocks))
         self._blocks.clear()
 
 
@@ -298,7 +299,7 @@ class MarkdownOrderedList(MarkdownList):
         width: 1fr;
     }
 
-    MarkdownOrderedList VerticalScroll {
+    MarkdownOrderedList Vertical {
         height: auto;
         width: 1fr;
     }
@@ -321,7 +322,7 @@ def compose(self) -> ComposeResult:
             if isinstance(block, MarkdownListItem):
                 bullet = MarkdownBullet()
                 bullet.symbol = f"{number}{suffix}".rjust(symbol_size + 1)
-                yield Horizontal(bullet, VerticalScroll(*block._blocks))
+                yield Horizontal(bullet, Vertical(*block._blocks))
 
         self._blocks.clear()
 
@@ -449,7 +450,7 @@ class MarkdownListItem(MarkdownBlock):
         height: auto;
     }
 
-    MarkdownListItem > VerticalScroll {
+    MarkdownListItem > Vertical {
         width: 1fr;
         height: auto;
     }
@@ -644,6 +645,18 @@ async def load(self, path: Path) -> bool:
         self.update(markdown)
         return True
 
+    def unhandled_token(self, token: Token) -> MarkdownBlock | None:
+        """Process an unhandled token.
+
+        Args:
+            token: The token to handle.
+
+        Returns:
+            Either a widget to be added to the output, or `None`.
+        """
+        del token
+        return None
+
     def update(self, markdown: str) -> None:
         """Update the document with new Markdown.
 
@@ -777,14 +790,18 @@ def update(self, markdown: str) -> None:
                             style_stack.pop()
 
                 stack[-1].set_content(content)
-            elif token.type == "fence":
-                output.append(
+            elif token.type in ("fence", "code_block"):
+                (stack[-1]._blocks if stack else output).append(
                     MarkdownFence(
                         self,
                         token.content.rstrip(),
                         token.info,
                     )
                 )
+            else:
+                external = self.unhandled_token(token)
+                if external is not None:
+                    (stack[-1]._blocks if stack else output).append(external)
 
         self.post_message(Markdown.TableOfContentsUpdated(self, table_of_contents))
         with self.app.batch_update():

src/textual/widgets/markdown.py

@@ -1,3 +1,3 @@
-from ._markdown import Markdown, MarkdownTableOfContents
+from ._markdown import Markdown, MarkdownBlock, MarkdownTableOfContents
 
-__all__ = ["MarkdownTableOfContents", "Markdown"]
+__all__ = ["MarkdownTableOfContents", "Markdown", "MarkdownBlock"]

tests/test_markdown.py

@@ -0,0 +1,91 @@
+"""Unit tests for the Markdown widget."""
+
+from __future__ import annotations
+
+from typing import Iterator
+
+import pytest
+from markdown_it.token import Token
+
+import textual.widgets._markdown as MD
+from textual.app import App, ComposeResult
+from textual.widget import Widget
+from textual.widgets import Markdown
+from textual.widgets.markdown import MarkdownBlock
+
+
+class UnhandledToken(MarkdownBlock):
+    def __init__(self, markdown: Markdown, token: Token) -> None:
+        super().__init__(markdown)
+        self._token = token
+
+    def __repr___(self) -> str:
+        return self._token.type
+
+
+class FussyMarkdown(Markdown):
+    def unhandled_token(self, token: Token) -> MarkdownBlock | None:
+        return UnhandledToken(self, token)
+
+
+class MarkdownApp(App[None]):
+    def __init__(self, markdown: str) -> None:
+        super().__init__()
+        self._markdown = markdown
+
+    def compose(self) -> ComposeResult:
+        yield FussyMarkdown(self._markdown)
+
+
+@pytest.mark.parametrize(
+    ["document", "expected_nodes"],
+    [
+        # Basic markup.
+        ("", []),
+        ("# Hello", [MD.MarkdownH1]),
+        ("## Hello", [MD.MarkdownH2]),
+        ("### Hello", [MD.MarkdownH3]),
+        ("#### Hello", [MD.MarkdownH4]),
+        ("##### Hello", [MD.MarkdownH5]),
+        ("###### Hello", [MD.MarkdownH6]),
+        ("---", [MD.MarkdownHorizontalRule]),
+        ("Hello", [MD.MarkdownParagraph]),
+        ("Hello\nWorld", [MD.MarkdownParagraph]),
+        ("> Hello", [MD.MarkdownBlockQuote, MD.MarkdownParagraph]),
+        ("- One\n-Two", [MD.MarkdownBulletList, MD.MarkdownParagraph]),
+        (
+            "1. One\n2. Two",
+            [MD.MarkdownOrderedList, MD.MarkdownParagraph, MD.MarkdownParagraph],
+        ),
+        ("    1", [MD.MarkdownFence]),
+        ("```\n1\n```", [MD.MarkdownFence]),
+        ("```python\n1\n```", [MD.MarkdownFence]),
+        ("""| One | Two |\n| :- | :- |\n| 1 | 2 |""", [MD.MarkdownTable]),
+        # Test for https://github.com/Textualize/textual/issues/2676
+        (
+            "- One\n```\nTwo\n```\n- Three\n",
+            [
+                MD.MarkdownBulletList,
+                MD.MarkdownParagraph,
+                MD.MarkdownFence,
+                MD.MarkdownBulletList,
+                MD.MarkdownParagraph,
+            ],
+        ),
+    ],
+)
+async def test_markdown_nodes(
+    document: str, expected_nodes: list[Widget | list[Widget]]
+) -> None:
+    """A Markdown document should parse into the expected Textual node list."""
+
+    def markdown_nodes(root: Widget) -> Iterator[MarkdownBlock]:
+        for node in root.children:
+            if isinstance(node, MarkdownBlock):
+                yield node
+            yield from markdown_nodes(node)
+
+    async with MarkdownApp(document).run_test() as pilot:
+        assert [
+            node.__class__ for node in markdown_nodes(pilot.app.query_one(Markdown))
+        ] == expected_nodes