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name: interactive-maps description: "It routes a researcher through safe Leafmap and Folium Streamlit workflows for tiled, raster, vector, and comparison maps." disable-model-invocation: true metadata: disco-role: operating license: MIT

Interactive maps

Use this leaf when a task needs a Leafmap-backed Streamlit map: basemaps and XYZ/QMS search, split views, heatmaps, marker clusters, WMS, COG/raster visualization, vector uploads, or NLS/Ordnance Survey tile overlays. Keep Earth Engine and housing-specific joins on their sibling routes.

Route the request

1. Select the rendering backend before reading data:
   • leafmap.foliumap for Folium controls, WMS/COG layers, XYZ tiles, and Map.to_streamlit.
   • leafmap.kepler for Kepler layer/config output and its Map.to_streamlit.
   • leafmap.deck for PyDeck-compatible maps rendered with st.pydeck_chart.
2. Classify the input as a local vector, point table, trusted WMS/COG service, XYZ/QMS provider, or prepared tile layer. Do not fetch a user-supplied URL to decide whether it is trusted. Use an exact allowlist for services that the application is willing to contact.
3. For a local GeoJSON, KML, or ZIP upload, run the bundled validator first. A zero exit status and its JSON report are the pre-render gate; a nonzero status is a user-correctable input error.
4. Follow the inspected signatures and concrete recipes in the references. Initialize empty selections before conditional UI branches, catch service and backend errors at the boundary, and show a readable Streamlit error rather than a traceback.
5. Render only after the relevant URL, bands/visualization parameters, vector geometry/CRS, and backend checks pass. Keep remote tile selection bounded and preserve provider attribution.

Operating links

• Inspected API reference — exact signatures, module locations, and backend render calls.
• Workflows — concrete map construction recipes, validation gates, split views, and NLS overlays.
• Data formats — local vector, point, WMS, COG, and XYZ input contracts.
• Troubleshooting — URL, CRS/driver, service, backend, visualization, and tile failure recovery.
• Offline vector validator — deterministic geometry count, CRS, bounds, and column report without network access.

Completion signals

A successful invocation has a selected backend, a validated input contract, and one of these observable render signals:

• Folium: a leafmap.foliumap.Map reaches to_streamlit(...).
• Kepler: a leafmap.kepler.Map reaches to_streamlit(...).
• PyDeck: a leafmap.deck.Map reaches st.pydeck_chart(...).

Rejected URLs, malformed vectors, missing optional backends, invalid COG visualization JSON, and failed WMS capabilities must become user-visible errors. Record remote-service limits and any unverified split-layer ordering; do not silently change backend or layer semantics.