render_ipyleaflet

render_ipyleaflet class

Reactively render an ipyleaflet map.

render_ipyleaflet(
    _fn: Optional[ValueFn[ValueT]] = None,
    *,
    width: Optional[str] = None,
    height: Optional[str] = None,
    fill: Optional[bool] = None,
    fillable: Optional[bool] = None,
    rate_policy: Optional[RatePolicy] = None,
    rate_delay: Optional[float] = None,
)

@render_ipyleaflet is a decorator that creates a render function – a function that returns the map to display and re-runs when the reactive values it reads change:

import ipyleaflet

from shinywidgets import render_ipyleaflet


@render_ipyleaflet
def map():
    return ipyleaflet.Map(center=(51.48, 0), zoom=12)

The render function should return an ipyleaflet.Map (requires pip install ipyleaflet) or a subclass of it, such as a leafmap.leafmap.Map.

In a filling layout, the map fills its container unless it has its own height (e.g., Layout(height="300px")). Default heights set by a subclass (e.g., leafmap’s 600px) are treated as unset.

Note

Accessing the rendered widget: the render function gains two read-only attributes: .value, the value it most recently returned, and .widget, the rendered Map instance. Map state can also be read reactively with .read("some_trait") (a shortcut for reactive_read() on .widget).

Responding to user interaction: read the map’s accessors in a reactive function (a @render.* function, @reactive.calc, or @reactive.effect), which re-runs whenever the user gestures, much like input.my_slider():

map.bounds(): the viewport, ((south, west), (north, east)).
map.zoom() and map.center(): the camera.
map.clicked(): the most recent map click.
map.drawn_features(): the shapes drawn on the map’s DrawControl.

Coordinates are [lat, lng], as ipyleaflet reports them (lonboard is (lng, lat)). The accessors can’t be read inside this output’s own render function, which builds a new map each time it runs. For anything beyond them, use map.read() (a shortcut for reactive_read() on map.widget).

Mutating the widget: use .widget to update the rendered map in place (e.g., change its zoom or center, or add layers); trait changes on the widget are synced to the browser.

Parameters

width : Optional[str] = None: A CSS length unit (e.g., "400px" or "100%") for the output’s width.
height : Optional[str] = None: A CSS length unit for the output’s height. When None (the default), the output is designed to fill the height of its parent container (see fill and fillable).
fill : Optional[bool] = None: Whether the output should grow or shrink to fit its parent container. When None (the default), this is True if height is not specified.
fillable : Optional[bool] = None: Whether the output container should fill available space (scrolling its contents on overflow). When None (the default), this is True if height is not specified.
rate_policy : Optional[RatePolicy] = None: How to rate-limit reactive_read() on the widget: "debounce" or "throttle". None (the default) debounces reactive_read() only if rate_delay is given; no accessor on this renderer declares a default.
rate_delay : Optional[float] = None: The rate-limit window in seconds (default 0.25). 0 disables rate limiting.
Each :
which :

render_ipyleaflet class

Note

Parameters

See also