chore(render.display): Improve error message (#1020)

gadenbuie · web-flow · commit f723c2bfca54 · 2024-01-19T11:12:31.000-05:00
diff --git a/shiny/render/_display.py b/shiny/render/_display.py
@@ -93,7 +93,7 @@ async def render(self) -> JsonifiableDict | None:
             ret = sync_value_fn()
             if ret is not None:
                 raise RuntimeError(
-                    "@render.display functions should not return values. (`None` is allowed)."
+                    "@render.display functions should not return values. Instead, @render.display dynamically renders every printable line within the function body. (`None` is a valid return value.)"
                 )
         finally:
             sys.displayhook = orig_displayhook

Original file line number	Diff line number	Diff line change
`@@ -93,7 +93,7 @@ async def render(self) -> JsonifiableDict \| None:`
`93`	`93`	`ret = sync_value_fn()`
`94`	`94`	`if ret is not None:`
`95`	`95`	`raise RuntimeError(`
`96`		- "@render.display functions should not return values. (`None` is allowed)."
	`96`	+ "@render.display functions should not return values. Instead, @render.display dynamically renders every printable line within the function body. (`None` is a valid return value.)"
`97`	`97`	`)`
`98`	`98`	`finally:`
`99`	`99`	`sys.displayhook = orig_displayhook`