Data driven lines

Style lines with a data-driven property

This source code of this example is adapted from the MapLibre GL JS example - Style lines with a data-driven property.

Uncomment the following line to install leafmap if needed.

In [ ]:

# %pip install "leafmap[maplibre]"

# %pip install "leafmap[maplibre]"

In [ ]:

import leafmap.maplibregl as leafmap

import leafmap.maplibregl as leafmap

To run this notebook, you will need an API key from MapTiler. Once you have the API key, you can uncomment the following code block and replace YOUR_API_KEY with your actual API key. Then, run the code block code to set the API key as an environment variable.

In [ ]:

# import os
# os.environ["MAPTILER_KEY"] = "YOUR_API_KEY"

# import os # os.environ["MAPTILER_KEY"] = "YOUR_API_KEY"

In [ ]:

m = leafmap.Map(center=[-122.483831, 37.828826], zoom=16, style="streets")
geojson = {
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "properties": {"color": "#F7455D"},
            "geometry": {
                "type": "LineString",
                "coordinates": [
                    [-122.4833858013153, 37.829607404976734],
                    [-122.4830961227417, 37.82932776098012],
                    [-122.4830746650696, 37.82932776098012],
                    [-122.48218417167662, 37.82889558180985],
                    [-122.48218417167662, 37.82890193740421],
                    [-122.48221099376678, 37.82868372835086],
                    [-122.4822163581848, 37.82868372835086],
                    [-122.48205006122589, 37.82801003030873],
                ],
            },
        },
        {
            "type": "Feature",
            "properties": {"color": "#33C9EB"},
            "geometry": {
                "type": "LineString",
                "coordinates": [
                    [-122.48393028974533, 37.829471820141016],
                    [-122.48395174741744, 37.82940826466351],
                    [-122.48395174741744, 37.829412501697064],
                    [-122.48423874378203, 37.829357420242125],
                    [-122.48422533273697, 37.829361657278575],
                    [-122.48459815979002, 37.8293425906126],
                    [-122.48458743095398, 37.8293447091313],
                    [-122.4847564101219, 37.82932776098012],
                    [-122.48474299907684, 37.829331998018276],
                    [-122.4849334359169, 37.829298101706186],
                    [-122.48492807149889, 37.82930022022615],
                    [-122.48509705066681, 37.82920488676767],
                    [-122.48509168624878, 37.82920912381288],
                    [-122.48520433902739, 37.82905870855876],
                    [-122.48519897460936, 37.82905870855876],
                    [-122.4854403734207, 37.828594749716714],
                    [-122.48543500900269, 37.82860534241688],
                    [-122.48571664094925, 37.82808206121068],
                    [-122.48570591211319, 37.82809689109353],
                    [-122.4858346581459, 37.82797189627337],
                    [-122.48582661151886, 37.82797825194729],
                    [-122.4859634041786, 37.82788503534145],
                    [-122.48595803976059, 37.82788927246246],
                    [-122.48605459928514, 37.82786596829394],
                ],
            },
        },
    ],
}
source = {"type": "geojson", "data": geojson}
m.add_source("lines", source)
# Use a get expression (https://maplibre.org/maplibre-style-spec/expressions/#get)
# to set the line-color to a feature property value.
layer = {
    "id": "lines",
    "type": "line",
    "source": "lines",
    "paint": {"line-width": 3, "line-color": ["get", "color"]},
}
m.add_layer(layer)
m

m = leafmap.Map(center=[-122.483831, 37.828826], zoom=16, style="streets") geojson = { "type": "FeatureCollection", "features": [ { "type": "Feature", "properties": {"color": "#F7455D"}, "geometry": { "type": "LineString", "coordinates": [ [-122.4833858013153, 37.829607404976734], [-122.4830961227417, 37.82932776098012], [-122.4830746650696, 37.82932776098012], [-122.48218417167662, 37.82889558180985], [-122.48218417167662, 37.82890193740421], [-122.48221099376678, 37.82868372835086], [-122.4822163581848, 37.82868372835086], [-122.48205006122589, 37.82801003030873], ], }, }, { "type": "Feature", "properties": {"color": "#33C9EB"}, "geometry": { "type": "LineString", "coordinates": [ [-122.48393028974533, 37.829471820141016], [-122.48395174741744, 37.82940826466351], [-122.48395174741744, 37.829412501697064], [-122.48423874378203, 37.829357420242125], [-122.48422533273697, 37.829361657278575], [-122.48459815979002, 37.8293425906126], [-122.48458743095398, 37.8293447091313], [-122.4847564101219, 37.82932776098012], [-122.48474299907684, 37.829331998018276], [-122.4849334359169, 37.829298101706186], [-122.48492807149889, 37.82930022022615], [-122.48509705066681, 37.82920488676767], [-122.48509168624878, 37.82920912381288], [-122.48520433902739, 37.82905870855876], [-122.48519897460936, 37.82905870855876], [-122.4854403734207, 37.828594749716714], [-122.48543500900269, 37.82860534241688], [-122.48571664094925, 37.82808206121068], [-122.48570591211319, 37.82809689109353], [-122.4858346581459, 37.82797189627337], [-122.48582661151886, 37.82797825194729], [-122.4859634041786, 37.82788503534145], [-122.48595803976059, 37.82788927246246], [-122.48605459928514, 37.82786596829394], ], }, }, ], } source = {"type": "geojson", "data": geojson} m.add_source("lines", source) # Use a get expression (https://maplibre.org/maplibre-style-spec/expressions/#get) # to set the line-color to a feature property value. layer = { "id": "lines", "type": "line", "source": "lines", "paint": {"line-width": 3, "line-color": ["get", "color"]}, } m.add_layer(layer) m