improvement: better leafmap formatters (#2852)

* Adds formatters for plotly and kepler.
* Warns about using the default leafmap formatter
* Smoke test for different backends. 

opengeos/leafmap#973 will help when doing
`import leafmap`

docs/api/plotting.md

@@ -110,6 +110,10 @@ selection, consider using [`mo.ui.altair_chart`](#marimo.ui.altair_chart).
 .. autofunction:: marimo.mpl.interactive
 ```
 
+## Leafmap support
+
+marimo supports rendering [Leafmap](https://leafmap.org/) maps using the `folium` and `plotly` backends.
+
 ## Other plotting libraries
 
 You can use all the popular plotting libraries with marimo. Such as:

marimo/_output/formatters/leafmap_formatters.py

@@ -1,12 +1,11 @@
 # Copyright 2024 Marimo. All rights reserved.
 from __future__ import annotations
 
-from typing import Any, cast
-
 from marimo._messaging.mimetypes import KnownMimeType
 from marimo._output.builder import h
 from marimo._output.formatters.formatter_factory import FormatterFactory
 from marimo._output.formatters.utils import src_or_src_doc
+from marimo._output.md import md
 from marimo._output.utils import flatten_string
 
 
@@ -16,18 +15,21 @@ def package_name() -> str:
         return "leafmap"
 
     def register(self) -> None:
-        import leafmap  # type: ignore[import-not-found]
+        # Different backends
+        # plotly is handled by PlotlyFormatter
+        import leafmap.foliumap as leafmap_folium  # type: ignore[import-untyped]
+        import leafmap.leafmap as leafmap  # type: ignore[import-untyped]
 
         from marimo._output import formatting
 
-        @formatting.formatter(leafmap.folium.Map)
+        @formatting.formatter(leafmap_folium.Map)
         def _show_folium_map(
-            fmap: leafmap.folium.Map,
+            fmap: leafmap_folium.Map,
         ) -> tuple[KnownMimeType, str]:
             # leafmap.folium.Map has a _repr_html_, which we have
             # another custom formatter for, but this wraps the map in an
             # additional iframe which can cause weird layout issues
-            html_content = cast(Any, fmap).to_html()
+            html_content = fmap.to_html()
             return (
                 "text/html",
                 flatten_string(
@@ -44,20 +46,46 @@ def _show_folium_map(
         def _show_map(
             lmap: leafmap.Map,
         ) -> tuple[KnownMimeType, str]:
-            # 540px is the pixel height that makes the map fit in the
-            # notebook without scrolling
-            height = lmap.layout.height or "540px"
-            width = lmap.layout.width or "100%"
-            html_content = lmap.to_html(width=width, height=height)
+            del lmap
             return (
                 "text/html",
-                (
+                md(
+                    """
+                    leafmap.Map objects are not supported in marimo.
+                    Please change the backend to `folium` or `plotly`.
+
+                    ```python
+                    import leafmap.foliumap as leafmap
+                    # or
+                    import leafmap.plotlymap as leafmap
+                    ```
+                    """
+                )
+                .callout()
+                .text,
+            )
+
+        # Kepler is an optional dependency
+        # so we don't want this to fail if it's not installed
+        try:
+            import leafmap.kepler as leafmap_kepler  # type: ignore[import-untyped]
+
+            @formatting.formatter(leafmap_kepler.Map)
+            def _show_kepler_map(
+                kmap: leafmap_kepler.Map,
+            ) -> tuple[KnownMimeType, str]:
+                contents = kmap.to_html() or ""
+                return (
+                    "text/html",
                     flatten_string(
                         h.iframe(
-                            **src_or_src_doc(html_content),
+                            **src_or_src_doc(contents),
                             onload="__resizeIframe(this)",
+                            style="min-height: 540px",
                             width="100%",
                         )
-                    )
-                ),
-            )
+                    ),
+                )
+
+        except (ImportError, ModuleNotFoundError):
+            pass

marimo/_output/formatters/plotly_formatters.py

@@ -25,6 +25,7 @@ def register(self) -> None:
         from marimo._output import formatting
 
         @formatting.formatter(plotly.graph_objects.Figure)
+        @formatting.formatter(plotly.graph_objects.FigureWidget)
         def _show_plotly_figure(
             fig: plotly.graph_objects.Figure,
         ) -> tuple[KnownMimeType, str]:

marimo/_smoke_tests/third_party/leafmap/backends.py

@@ -0,0 +1,86 @@
+import marimo
+
+__generated_with = "0.9.17"
+app = marimo.App(width="medium")
+
+
+@app.cell
+def __():
+    import marimo as mo
+    return (mo,)
+
+
+@app.cell
+def __():
+    import leafmap as default_leamap
+    import leafmap.leafmap as leafmap
+    import leafmap.foliumap as leafmap_folium
+    import leafmap.plotlymap as leafmap_plotly
+    return default_leamap, leafmap, leafmap_folium, leafmap_plotly
+
+
+@app.cell
+def __():
+    import keplergl
+    import leafmap.kepler as leafmap_kepler
+    return keplergl, leafmap_kepler
+
+
+@app.cell
+def __(default_leamap):
+    default_leamap.Map
+    return
+
+
+@app.cell
+def __(leafmap):
+    data = leafmap.examples.datasets.countries_geojson
+    return (data,)
+
+
+@app.cell
+def __(data, leafmap):
+    _m = leafmap.Map()
+    _m.add_data(
+        data,
+        column="POP_EST",
+        scheme="Quantiles",
+        cmap="Blues",
+        legend_title="Population",
+    )
+    _m
+    return
+
+
+@app.cell
+def __(leafmap_plotly):
+    _m = leafmap_plotly.Map(center=(40, -100), zoom=3, height=500)
+    _m
+    return
+
+
+@app.cell
+def __(data, leafmap_folium):
+    _m = leafmap_folium.Map()
+    _m.add_data(
+        data,
+        column="POP_EST",
+        scheme="Quantiles",
+        cmap="Blues",
+        legend_title="Population",
+    )
+    _m
+    return
+
+
+@app.cell
+def __(leafmap_kepler):
+    _m = leafmap_kepler.Map(
+        center=[40, -100], zoom=2, height=600, widescreen=False
+    )
+    _m
+    return
+
+
+if __name__ == "__main__":
+    app.run()

pyproject.toml

@@ -145,6 +145,7 @@ installer = "uv"
 dependencies = [
     "mypy~=1.10.1",
     # Types for mypy
+    "leafmap~=0.39.2",
     "panel~=1.5.3",
     "polars~=1.9.0",
     "narwhals>=1.12.0",
@@ -179,7 +180,7 @@ python = ["3.9","3.10", "3.11", "3.12"]
 test = "pytest{env:HATCH_TEST_ARGS:} {args:tests}"
 default = "pytest{env:HATCH_TEST_ARGS:} {args:tests}"
 # This is used externally from the narwhals repo to run our tests from their repo.
-# This should include any tests that may use narwhals. 
+# This should include any tests that may use narwhals.
 # It is ok if we test more than narwhals here, but we should not test less.
 test-narwhals = """
     pytest{env:HATCH_TEST_ARGS:} \
@@ -267,7 +268,7 @@ ignore = [
     "D301", # Use r""" if any backslashes in a docstring
     # TODO: we should fix these, and enable this rule
     "PT011", # `pytest.raises(ValueError)` is too broad, set the `match` parameter or use a more specific exception
-    "E501", # Line too long, we still trim 
+    "E501", # Line too long, we still trim
 ]
 extend-select = [
     # pyflakes