Example of using Folium in Panel - Notebook for Gallery (#1189)

examples/gallery/external/Folium.ipynb

@@ -0,0 +1,196 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Demonstrates the use of [`Folium`](https://python-visualization.github.io/folium/) in Panel."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import folium as fm\n",
+    "import pandas as pd\n",
+    "import param\n",
+    "import panel as pn\n",
+    "import random\n",
+    "pn.extension()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "You can use `Folium` directly in a Jupyter Notebook"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def get_map(lat=20.5936832, long=78.962883, zoom_start=5):\n",
+    "    return fm.Map(location=[lat,long], zoom_start=zoom_start)\n",
+    "\n",
+    "map = get_map()\n",
+    "\n",
+    "pn.panel(map)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Interactive Panel app using Folium\n",
+    "\n",
+    "Let build an interactive Panel application using Folium.\n",
+    "\n",
+    "Lets **define some data**."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def get_df_aqi(lat_bounds=(10,30), long_bounds=(70,90), points_count=40):\n",
+    "    aqi = {\n",
+    "        \"Latitude\": [random.uniform(*lat_bounds) for _ in range(0,points_count)],\n",
+    "        \"Longitude\": [random.uniform(*long_bounds) for _ in range(0,points_count)],\n",
+    "        \"AQI\": [random.uniform(0,500) for _ in range(0,points_count)],\n",
+    "    }\n",
+    "    return pd.DataFrame(aqi)\n",
+    "\n",
+    "df_aqi = get_df_aqi()\n",
+    "df_aqi.sample(5)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Lets define some functionality to **add the data to the map** as circles"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def add_aqi_circles(map, df_aqi):\n",
+    "    green_p1  = fm.map.FeatureGroup()\n",
+    "    yellow_p1 = fm.map.FeatureGroup()\n",
+    "    orange_p1 = fm.map.FeatureGroup()\n",
+    "    red_p1    = fm.map.FeatureGroup()\n",
+    "    purple_p1 = fm.map.FeatureGroup()\n",
+    "    maroon_p1 = fm.map.FeatureGroup()\n",
+    "\n",
+    "    for _, row in df_aqi.iterrows():\n",
+    "        if row.AQI<50:\n",
+    "            feature_group = green_p1\n",
+    "            fill_color = \"green\"\n",
+    "        elif row.AQI < 100:\n",
+    "            feature_group = yellow_p1\n",
+    "            fill_color = \"yellow\"\n",
+    "        elif row.AQI < 150:\n",
+    "            feature_group = orange_p1\n",
+    "            fill_color = \"orange\"\n",
+    "        elif row.AQI < 200:\n",
+    "            feature_group = red_p1\n",
+    "            fill_color = \"red\"\n",
+    "        elif row.AQI < 300:\n",
+    "            feature_group = purple_p1\n",
+    "            fill_color='purple'\n",
+    "        else:\n",
+    "            feature_group = maroon_p1\n",
+    "            fill_color = \"maroon\"\n",
+    "\n",
+    "        feature_group.add_child(\n",
+    "            fm.CircleMarker(\n",
+    "                [row.Latitude, row.Longitude],\n",
+    "                radius=10, \n",
+    "                fill=True,\n",
+    "                fill_color=fill_color,\n",
+    "                fill_opacity=0.7\n",
+    "            )\n",
+    "        )\n",
+    "\n",
+    "    map.add_child(green_p1)\n",
+    "    map.add_child(yellow_p1)\n",
+    "    map.add_child(orange_p1)\n",
+    "    map.add_child(red_p1)\n",
+    "    map.add_child(purple_p1)\n",
+    "\n",
+    "add_aqi_circles(map, df_aqi)\n",
+    "pn.panel(map)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Lets put it all together into an **interactive app** where the user can select the number of data points to generate and display."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class PanelFoliumMap(param.Parameterized):\n",
+    "    points_count = param.Integer(20, bounds=(10,100))\n",
+    "        \n",
+    "    def __init__(self, **params):\n",
+    "        super().__init__(**params)\n",
+    "        self.map = get_map()\n",
+    "        self.html_pane = pn.pane.HTML(sizing_mode=\"stretch_width\", min_height=600)    \n",
+    "        self.view = pn.Column(\n",
+    "            self.param.points_count,\n",
+    "            self.html_pane,\n",
+    "            sizing_mode=\"stretch_width\", min_height=600,\n",
+    "        )\n",
+    "        self._update_map()\n",
+    "\n",
+    "    @param.depends(\"points_count\", watch=True)\n",
+    "    def _update_map(self):\n",
+    "        self.map = get_map()\n",
+    "        df_aqi = get_df_aqi(points_count=self.points_count)\n",
+    "        add_aqi_circles(self.map, df_aqi)\n",
+    "        self.html_pane.object = self.map\n",
+    "\n",
+    "        \n",
+    "app = PanelFoliumMap()\n",
+    "app.view.embed()"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.7.5"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}

panel/pane/plot.py

@@ -166,3 +166,20 @@ def _get_properties(self):
         if self.height is None: p["height"] = height
 
         return p
+
+
+class Folium(HTML):
+    """
+    The Folium pane wraps Folium map components.
+    """
+
+    sizing_mode = param.ObjectSelector(default='stretch_width', objects=[
+        'fixed', 'stretch_width', 'stretch_height', 'stretch_both',
+        'scale_width', 'scale_height', 'scale_both', None])
+
+    priority = 0.6
+
+    @classmethod
+    def applies(cls, obj):
+        return (getattr(obj, '__module__', '').startswith('folium.') and
+                hasattr(obj, "_repr_html_"))

panel/viewable.py

@@ -194,7 +194,8 @@ def __init__(self, **params):
             params.get('height_policy') is None and
             'sizing_mode' not in params):
             params['sizing_mode'] = 'fixed'
-        elif not self.param.sizing_mode.constant and not self.param.sizing_mode.readonly:
+        elif (not (self.param.sizing_mode.constant or self.param.sizing_mode.readonly) and
+              type(self).sizing_mode is None):
             params['sizing_mode'] = params.get('sizing_mode', config.sizing_mode)
         super(Layoutable, self).__init__(**params)
 

setup.py

@@ -112,7 +112,8 @@ def run(self):
     'scipy',
     'nbsmoke >=0.2.0',
     'pytest-cov',
-    'codecov'
+    'codecov',
+    'folium',
 ]
 
 extras_require = {