Use source code for demo directly in demo (#194)

Co-authored-by: Josh Karpel <josh.karpel@gmail.com>

docs/changelog.md

@@ -7,6 +7,11 @@
 ### Added
 
 - [#185](https://github.com/JoshKarpel/spiel/pull/185) The docs page now includes copy-to-clipboard buttons on all code snippets.
+- [#194](https://github.com/JoshKarpel/spiel/pull/194) The demo slides now render their own source code directly to demo bindings functionality.
+
+### Changed
+
+- [#194](https://github.com/JoshKarpel/spiel/pull/194) The `Deck.slide` decorator now returns the decorated function, not the `Slide` it was attached to.
 
 ## `0.4.3` | 2023-01-02
 

mkdocs.yml

@@ -54,7 +54,6 @@ plugins:
             - https://rich.readthedocs.io/en/stable/objects.inv
             - https://textual.textualize.io/objects.inv
 
-
 markdown_extensions:
   - admonition
   - pymdownx.details

spiel/deck.py

@@ -22,7 +22,7 @@ class Deck(Sequence[Slide]):
         self,
         title: str = "",
         bindings: Mapping[str, Callable[..., None]] | None = None,
-    ) -> Callable[[Content], Slide]:
+    ) -> Callable[[Content], Content]:
         """
         A decorator that creates a new slide in the deck,
         with the decorated function as the `Slide`'s `content`.
@@ -35,14 +35,15 @@ class Deck(Sequence[Slide]):
                 when on this slide.
         """
 
-        def slideify(content: Content) -> Slide:
-            slide = Slide(
-                title=title,
-                content=content,
-                bindings=bindings or {},
+        def slideify(content: Content) -> Content:
+            self.add_slides(
+                Slide(
+                    title=title,
+                    content=content,
+                    bindings=bindings or {},
+                )
             )
-            self.add_slides(slide)
-            return slide
+            return content
 
         return slideify
 

spiel/demo/demo.py

@@ -6,7 +6,7 @@ import socket
 from datetime import datetime
 from math import cos, floor, pi
 from pathlib import Path
-from textwrap import dedent
+from textwrap import dedent, indent
 
 from click import edit
 from rich.align import Align
@@ -375,7 +375,18 @@ def edit_this_file(suspend: SuspendType) -> None:
     },
 )
 def bindings() -> RenderableType:
-    edit_function_src = dedent("".join(inspect.getsourcelines(edit_this_file)[0]))
+    edit_this_file_source_lines, _ = inspect.getsourcelines(edit_this_file)
+    this_slide_source_lines, _ = inspect.getsourcelines(bindings)
+    source_lines = [
+        *edit_this_file_source_lines,
+        "\n",  # blank line between the two functions
+        *this_slide_source_lines[:7],  # up through the slide's def
+        "    ...",  # replace the slide body with a "..."
+    ]
+
+    # get the indentation right for the triple-quoted string below
+    source_code = indent("".join(source_lines), " " * 8).lstrip()
+
     return pad_markdown(
         f"""\
         ## Custom Per-Slide Key Bindings
@@ -383,20 +394,6 @@ def bindings() -> RenderableType:
         Custom keybindings can be added on a per-slide basis using the `bindings` argument of `@slide`,
         which takes a mapping of key names to callables to call when that key is pressed.
 
-        ```python
-        def edit_this_file(suspend: SuspendType) -> None:
-            with suspend():
-                edit(filename=__file__)
-
-        @deck.slide(
-            title="Bindings",
-            bindings={{
-                "e": edit_this_file,
-            }},
-        )
-        def bindings() -> RenderableType:
-            ...
-        ```
 
         If the callable takes an argument named `suspend`,
         it will be passed a function that, when used as a context manager,
@@ -406,6 +403,10 @@ def bindings() -> RenderableType:
         and opens your `$EDITOR` on the demo deck's Python file.
         Try pressing `e`!
 
+        ```python
+        {source_code}
+        ```
+
         Due to reloading, any changes you make will be reflected in the
         presentation you're seeing right now.
         """