useMapContext

Reads the current map context from MapBase
Use it in custom layers when you need the resolved map size, normalized features, or the shared path generator
Throws an error if used outside MapBase

Return value

Adapter	Type
@d3-maps/vue	ComputedRef<MapContext>
@d3-maps/react	MapContext

See MapContext API

Usage

<script setup lang="ts">
import { computed } from 'vue'
import { useMapContext } from '@d3-maps/vue'

const context = useMapContext()
const featureCountLabel = computed(() => `${context.value.features.length} features`)
</script>

<template>
  <text
    v-if="featureCountLabel"
    x="12"
    y="20"
    font-size="12"
    fill="#111"
  >
    {{ featureCountLabel }}
  </text>
</template>

Best Practice

• Use useMapContext in components rendered inside MapBase
• Use MapBase slot/render-prop context when that already gives you what you need
• Use useCreateMapContext in the parent and pass the same context object to both MapBase and any sibling UI that needs it