Feature Query & Filter¶

This notebook demonstrates how to programmatically filter layers and query visible features on MapLibre maps.

In [ ]:

# %pip install anymap-ts

# %pip install anymap-ts

Load GeoJSON Data¶

In [ ]:

from anymap_ts import Map

m = Map(center=[-98.5, 39.8], zoom=3)
m.add_geojson(
    "https://d2ad6b4ur7yvpq.cloudfront.net/naturalearth-3.3.0/ne_110m_admin_0_countries.geojson",
    name="countries",
    layer_type="fill",
    paint={
        "fill-color": "#627BC1",
        "fill-opacity": 0.5,
        "fill-outline-color": "#333",
    },
)
m

from anymap_ts import Map m = Map(center=[-98.5, 39.8], zoom=3) m.add_geojson( "https://d2ad6b4ur7yvpq.cloudfront.net/naturalearth-3.3.0/ne_110m_admin_0_countries.geojson", name="countries", layer_type="fill", paint={ "fill-color": "#627BC1", "fill-opacity": 0.5, "fill-outline-color": "#333", }, ) m

Apply a Filter¶

Show only countries with population greater than 100 million.

In [ ]:

m.set_filter("countries", [">", ["get", "pop_est"], 100000000])

m.set_filter("countries", [">", ["get", "pop_est"], 100000000])

Change Filter¶

Show only European countries.

In [ ]:

m.set_filter("countries", ["==", ["get", "continent"], "Europe"])

m.set_filter("countries", ["==", ["get", "continent"], "Europe"])

Clear Filter¶

Pass None to clear the filter and show all features.

In [ ]:

m.set_filter("countries", None)

m.set_filter("countries", None)

Query Rendered Features¶

Query features currently visible in the viewport.

In [ ]:

import time

m.query_rendered_features(layers=["countries"])
time.sleep(1)  # Wait for async response
features = m.queried_features
print(f"Number of features: {len(features.get('features', []))}")

import time m.query_rendered_features(layers=["countries"]) time.sleep(1) # Wait for async response features = m.queried_features print(f"Number of features: {len(features.get('features', []))}")

Query with Filter Expression¶

Query only features matching a filter.

In [ ]:

m.query_rendered_features(
    layers=["countries"],
    filter_expression=["==", ["get", "continent"], "Africa"],
)
time.sleep(1)
features = m.queried_features
print(f"African countries in viewport: {len(features.get('features', []))}")
for f in features.get("features", [])[:5]:
    print(f"  - {f.get('properties', {}).get('name', 'Unknown')}")

m.query_rendered_features( layers=["countries"], filter_expression=["==", ["get", "continent"], "Africa"], ) time.sleep(1) features = m.queried_features print(f"African countries in viewport: {len(features.get('features', []))}") for f in features.get("features", [])[:5]: print(f" - {f.get('properties', {}).get('name', 'Unknown')}")