136 lines
4.9 KiB
Python
136 lines
4.9 KiB
Python
from typing import Optional, Union
|
|
|
|
from branca.element import MacroElement
|
|
from jinja2 import Template
|
|
|
|
from folium.elements import JSCSSMixin
|
|
from folium.map import Layer
|
|
from folium.utilities import JsCode, camelize, parse_options
|
|
|
|
|
|
class Realtime(JSCSSMixin, MacroElement):
|
|
"""Put realtime data on a Leaflet map: live tracking GPS units,
|
|
sensor data or just about anything.
|
|
|
|
Based on: https://github.com/perliedman/leaflet-realtime
|
|
|
|
Parameters
|
|
----------
|
|
source: str, dict, JsCode
|
|
The source can be one of:
|
|
|
|
* a string with the URL to get data from
|
|
* a dict that is passed to javascript's `fetch` function
|
|
for fetching the data
|
|
* a `folium.JsCode` object in case you need more freedom.
|
|
start: bool, default True
|
|
Should automatic updates be enabled when layer is added
|
|
on the map and stopped when layer is removed from the map
|
|
interval: int, default 60000
|
|
Automatic update interval, in milliseconds
|
|
get_feature_id: str or JsCode, optional
|
|
A JS function with a geojson `feature` as parameter
|
|
default returns `feature.properties.id`
|
|
Function to get an identifier to uniquely identify a feature over time
|
|
update_feature: str or JsCode, optional
|
|
A JS function with a geojson `feature` as parameter
|
|
Used to update an existing feature's layer;
|
|
by default, points (markers) are updated, other layers are discarded
|
|
and replaced with a new, updated layer.
|
|
Allows to create more complex transitions,
|
|
for example, when a feature is updated
|
|
remove_missing: bool, default False
|
|
Should missing features between updates been automatically
|
|
removed from the layer
|
|
container: Layer, default GeoJson
|
|
The container will typically be a `FeatureGroup`, `MarkerCluster` or
|
|
`GeoJson`, but it can be anything that generates a javascript
|
|
L.LayerGroup object, i.e. something that has the methods
|
|
`addLayer` and `removeLayer`.
|
|
|
|
Other keyword arguments are passed to the GeoJson layer, so you can pass
|
|
`style`, `point_to_layer` and/or `on_each_feature`. Make sure to wrap
|
|
Javascript functions in the JsCode class.
|
|
|
|
Examples
|
|
--------
|
|
>>> from folium import JsCode
|
|
>>> m = folium.Map(location=[40.73, -73.94], zoom_start=12)
|
|
>>> rt = Realtime(
|
|
... "https://raw.githubusercontent.com/python-visualization/folium-example-data/main/subway_stations.geojson",
|
|
... get_feature_id=JsCode("(f) => { return f.properties.objectid; }"),
|
|
... point_to_layer=JsCode(
|
|
... "(f, latlng) => { return L.circleMarker(latlng, {radius: 8, fillOpacity: 0.2})}"
|
|
... ),
|
|
... interval=10000,
|
|
... )
|
|
>>> rt.add_to(m)
|
|
"""
|
|
|
|
_template = Template(
|
|
"""
|
|
{% macro script(this, kwargs) %}
|
|
var {{ this.get_name() }}_options = {{ this.options|tojson }};
|
|
{% for key, value in this.functions.items() %}
|
|
{{ this.get_name() }}_options["{{key}}"] = {{ value }};
|
|
{% endfor %}
|
|
|
|
{% if this.container -%}
|
|
{{ this.get_name() }}_options["container"]
|
|
= {{ this.container.get_name() }};
|
|
{% endif -%}
|
|
|
|
var {{ this.get_name() }} = L.realtime(
|
|
{% if this.src is string or this.src is mapping -%}
|
|
{{ this.src|tojson }},
|
|
{% else -%}
|
|
{{ this.src.js_code }},
|
|
{% endif -%}
|
|
{{ this.get_name() }}_options
|
|
);
|
|
{{ this._parent.get_name() }}.addLayer(
|
|
{{ this.get_name() }}._container);
|
|
{% endmacro %}
|
|
"""
|
|
)
|
|
|
|
default_js = [
|
|
(
|
|
"Leaflet_Realtime_js",
|
|
"https://cdnjs.cloudflare.com/ajax/libs/leaflet-realtime/2.2.0/leaflet-realtime.js",
|
|
)
|
|
]
|
|
|
|
def __init__(
|
|
self,
|
|
source: Union[str, dict, JsCode],
|
|
start: bool = True,
|
|
interval: int = 60000,
|
|
get_feature_id: Union[JsCode, str, None] = None,
|
|
update_feature: Union[JsCode, str, None] = None,
|
|
remove_missing: bool = False,
|
|
container: Optional[Layer] = None,
|
|
**kwargs
|
|
):
|
|
super().__init__()
|
|
self._name = "Realtime"
|
|
self.src = source
|
|
self.container = container
|
|
|
|
kwargs["start"] = start
|
|
kwargs["interval"] = interval
|
|
if get_feature_id is not None:
|
|
kwargs["get_feature_id"] = JsCode(get_feature_id)
|
|
if update_feature is not None:
|
|
kwargs["update_feature"] = JsCode(update_feature)
|
|
kwargs["remove_missing"] = remove_missing
|
|
|
|
# extract JsCode objects
|
|
self.functions = {}
|
|
for key, value in list(kwargs.items()):
|
|
if isinstance(value, JsCode):
|
|
self.functions[camelize(key)] = value.js_code
|
|
kwargs.pop(key)
|
|
|
|
self.options = parse_options(**kwargs)
|