Use a fallback image
Use a coalesce expression to display another image when a requested image is not available.
---
title: Use a fallback image
description: Use a coalesce expression to display another image when a requested image is not available.
options:
center: [-77, 38.75]
zoom: 5
style:
layers:
- type: symbol
icon-image:
- coalesce
- [image, [concat, "maki:", [get, icon]]]
- [image, maki:marker]
extends: https://styles.trailsta.sh/osm-liberty.json
---
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
-77.03238901390978,
38.913188059745586
]
},
"properties": {
"title": "Washington DC",
"icon": "monument"
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
-79.9959,
40.4406
]
},
"properties": {
"title": "Pittsburgh",
"icon": "bridges"
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
-76.2859,
36.8508
]
},
"properties": {
"title": "Norfolk",
"icon": "harbor"
}
}
]
}