npm package: @radiantstatic/vue3-google-map
Description: A set of composable components for easy use of Google Maps in your Vue 3 projects.
Latest version: 0.21.0

# vue3-google-map

![Build Status](https://github.com/inocan-group/vue3-google-map/actions/workflows/build.yml/badge.svg)
[![License](https://img.shields.io/github/license/inocan-group/vue3-google-map)](https://github.com/inocan-group/vue3-google-map/blob/develop/LICENSE)

> Composable components for easy use of Google Maps with Vue 3

`vue3-google-map` offers a set of composable components for easy use of Google Maps in your Vue 3 projects.

Note: Please refer to the [documentation site](https://vue3-google-map.com/) for rendered examples.

## Table of Contents

- [Getting Started](#getting-started)
  - [Installation](#installation)
  - [Your First Map](#your-first-map)
- [Components](#components)
  - [Advanced Marker](#advanced-marker)
  - [Marker](#marker)
  - [Polyline](#polyline)
  - [Polygon](#polygon)
  - [Rectangle](#rectangle)
  - [Circle](#circle)
  - [Info Window](#info-window)
  - [Custom Marker](#custom-marker)
  - [Custom Control](#custom-control)
  - [Marker Cluster](#marker-cluster)
  - [Heatmap Layer](#heatmap-layer)
- [Advanced Usage](#advanced-usage)
- [Contribution](#contribution)
- [License](#license)

## Getting Started

### Installation

#### NPM

```bash
npm install vue3-google-map
# OR
pnpm add vue3-google-map
```

#### CDN

Include the following script tag in your `index.html` (make sure to include it after Vue 3's global build).

```html
<script src="https://unpkg.com/vue3-google-map"></script>
```

All the map components are available on the `Vue3GoogleMap` global variable.

[Codepen demo](https://codepen.io/husamibrahim/pen/poQXZbR)

### Your First Map

To construct a map using `vue3-google-map` you'll need to use the base `GoogleMap` component which receives your [Google Maps API key](https://developers.google.com/maps/documentation/javascript/get-api-key), styles (e.g. setting width and height), and any [MapOptions](https://developers.google.com/maps/documentation/javascript/reference/map#MapOptions) to configure your map ([see this](https://github.com/inocan-group/vue3-google-map/blob/develop/src/components/GoogleMap.vue#L36-L230) for all the supported `MapOptions`).
Other map features can be added to your map by passing map subcomponents ([Marker](#marker), [Polyline](#polyline), [Polygon](#polygon), [Rectangle](#rectangle), [Circle](#circle), [InfoWindow](#info-window), [CustomMarker](#custom-marker), [CustomControl](#custom-control), or [MarkerCluster](#marker-cluster)) to the default slot of the `GoogleMap` component.

The [the following events](https://developers.google.com/maps/documentation/javascript/reference/map#Map-Events) will be emitted by the `GoogleMap` component and can be listened to by using `@event_name`.

```vue
<script setup>
import { GoogleMap, Marker } from 'vue3-google-map'

const center = { lat: 40.689247, lng: -74.044502 }
</script>

<template>
  <GoogleMap
  api-key="YOUR_GOOGLE_MAPS_API_KEY"
  style="width: 100%; height: 500px"
  :center="center"
  :zoom="15"
  >
    <Marker :options="{ position: center }" />
  </GoogleMap>
</template>
```

## Components

This library is intended to be used in a composable fashion. Therefore you will find yourself using nested components to build your map rather than just a complicated inline format.

The main mapping component is `GoogleMap`, however the following components are available at your disposal:

- [AdvancedMarker](#advanced-marker)
- [Marker](#marker)
- [Polyline](#polyline)
- [Polygon](#polygon)
- [Rectangle](#rectangle)
- [Circle](#circle)
- [InfoWindow](#info-window)
- [CustomMarker](#custom-marker)
- [CustomControl](#custom-control)
- [MarkerCluster](#marker-cluster)

### Advanced Marker

Use the `AdvancedMarker` component to draw markers, drop pins or any custom icons on a map. `AdvancedMarker` is the new version offered by google when deprecated the `Marker` component ([read more here](https://developers.google.com/maps/deprecations#googlemapsmarker_in_the_deprecated_as_of_february_2024)).

In order to use the `AdvancedMarker` component is necessary to specify a MapId on declaring the `GoogleMap` component ([see more here](https://developers.google.com/maps/documentation/javascript/advanced-markers/start#create_a_map_id)).

#### Options

You can pass a [AdvancedMarkerElementOptions](https://developers.google.com/maps/documentation/javascript/reference/advanced-markers#AdvancedMarkerElementOptions) object to the `options` prop to configure your marker.

You can also pass a [PinElementOptions interface](https://developers.google.com/maps/documentation/javascript/reference/advanced-markers#PinElementOptions) object to custumize pin used by the marker.

```vue
<script setup>
import { GoogleMap, AdvancedMarker } from 'vue3-google-map'

const center = { lat: 40.689247, lng: -74.044502 }
const markerOptions = { position: center, label: 'L', title: 'LADY LIBERTY' }
const pinOptions = { background: '#FBBC04' }
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    mapId="DEMO_MAP_ID"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="15"
  >
    <AdvancedMarker :options="markerOptions" :pin-options="pinOptions"/>
  </GoogleMap>
</template>
```

#### Events

You can listen for [the following events](https://developers.google.com/maps/documentation/javascript/reference/advanced-markers#AdvancedMarkerElement-Events) on the `AdvancedMarker` component.

### Marker

Use the `Marker` component to draw markers, drop pins or any custom icons on a map.

#### Options

You can pass a [MarkerOptions](https://developers.google.com/maps/documentation/javascript/reference/marker#MarkerOptions) object to the `options` prop to configure your marker.

```vue
<script setup>
import { GoogleMap, Marker } from 'vue3-google-map'

const center = { lat: 40.689247, lng: -74.044502 }
const markerOptions = { position: center, label: 'L', title: 'LADY LIBERTY' }
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="15"
  >
    <Marker :options="markerOptions" />
  </GoogleMap>
</template>
```

#### Events

You can listen for [the following events](https://developers.google.com/maps/documentation/javascript/reference/marker#Marker-Events) on the `Marker` component.

### Polyline

Use the `Polyline` component to draw paths and arbitrary shapes on a map.

#### Options

You can pass a [PolylineOptions](https://developers.google.com/maps/documentation/javascript/reference/polygon#PolylineOptions) object to the `options` prop to configure your polyline.

```vue
<script setup>
import { GoogleMap, Polyline } from 'vue3-google-map'

const center = { lat: 0, lng: -180 }
const flightPlanCoordinates = [
  { lat: 37.772, lng: -122.214 },
  { lat: 21.291, lng: -157.821 },
  { lat: -18.142, lng: 178.431 },
  { lat: -27.467, lng: 153.027 },
]
const flightPath = {
  path: flightPlanCoordinates,
  geodesic: true,
  strokeColor: '#FF0000',
  strokeOpacity: 1.0,
  strokeWeight: 2,
}
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="3"
  >
    <Polyline :options="flightPath" />
  </GoogleMap>
</template>
```

#### Events

You can listen for [the following events](https://developers.google.com/maps/documentation/javascript/reference/polygon#Polyline-Events) on the `Polyline` component.

### Polygon

Use the `Polygon` component to draw polgons (arbitrary number of sides) on a map.

#### Options

You can pass a [PolylgonOptions](https://developers.google.com/maps/documentation/javascript/reference/polygon#PolygonOptions) object to the `options` prop to configure your polyline.

```vue
<script setup>
import { GoogleMap, Polygon } from 'vue3-google-map'

const center = { lat: 24.886, lng: -70.268 }
const triangleCoords = [
  { lat: 25.774, lng: -80.19 },
  { lat: 18.466, lng: -66.118 },
  { lat: 32.321, lng: -64.757 },
  { lat: 25.774, lng: -80.19 },
]
const bermudaTriangle = {
  paths: triangleCoords,
  strokeColor: '#FF0000',
  strokeOpacity: 0.8,
  strokeWeight: 2,
  fillColor: '#FF0000',
  fillOpacity: 0.35,
}
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="5"
  >
    <Polygon :options="bermudaTriangle" />
  </GoogleMap>
</template>
```

#### Events

You can listen for [the following events](https://developers.google.com/maps/documentation/javascript/reference/polygon#Polygon-Events) on the `Polygon` component.

### Rectangle

Use the `Rectangle` component to draw simple rectangles on a map.

#### Options

You can pass a [RectangleOptions](https://developers.google.com/maps/documentation/javascript/reference/polygon#RectangleOptions) object to the `options` prop to configure your rectangle.

```vue
<script setup>
import { GoogleMap, Rectangle } from 'vue3-google-map'

const center = { lat: 33.678, lng: -116.243 }
const rectangle = {
  strokeColor: '#FF0000',
  strokeOpacity: 0.8,
  strokeWeight: 2,
  fillColor: '#FF0000',
  fillOpacity: 0.35,
  bounds: {
    north: 33.685,
    south: 33.671,
    east: -116.234,
    west: -116.251,
  },
}
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    mapTypeId="terrain"
    :center="center"
    :zoom="11"
  >
    <Rectangle :options="rectangle" />
  </GoogleMap>
</template>
```

#### Events

You can listen for [the following events](https://developers.google.com/maps/documentation/javascript/reference/polygon#Rectangle-Events) on the `Rectangle` component.

### Circle

Use the `Circle` component to draw circles on a map.

#### Options

You can pass a [CircleOptions](https://developers.google.com/maps/documentation/javascript/reference/polygon#CircleOptions) object to the `options` prop to configure your circle.

```vue
<script setup>
import { GoogleMap, Circle } from 'vue3-google-map'

const center = { lat: 37.09, lng: -95.712 }
const cities = {
  chicago: {
    center: { lat: 41.878, lng: -87.629 },
    population: 2714856,
  },
  newyork: {
    center: { lat: 40.714, lng: -74.005 },
    population: 8405837,
  },
  losangeles: {
    center: { lat: 34.052, lng: -118.243 },
    population: 3857799,
  },
  vancouver: {
    center: { lat: 49.25, lng: -123.1 },
    population: 603502,
  },
}

const circles = {}

for (const key in cities) {
  circles[key] = {
    center: cities[key].center,
    radius: Math.sqrt(cities[key].population) * 100,
    strokeColor: '#FF0000',
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: '#FF0000',
    fillOpacity: 0.35,
  }
}
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    mapTypeId="terrain"
    :center="center"
    :zoom="4"
  >
    <Circle v-for="circle in circles" :options="circle" />
  </GoogleMap>
</template>
```

#### Events

You can listen for [the following events](https://developers.google.com/maps/documentation/javascript/reference/polygon#Circle-Events) on the `Circle` component.

### Info Window

Use the `InfoWindow` component to display content in a popup window above the map, at a given location.

#### Options

You can pass an [InfoWindowOptions](https://developers.google.com/maps/documentation/javascript/reference#InfoWindowOptions) object to the `options` prop to configure your info window. Note that you can optionally pass your content to the default slot of the `InfoWindow` component.

```vue
<script setup>
import { GoogleMap, InfoWindow } from 'vue3-google-map'

const center = { lat: -33.9, lng: 151.1 }
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="10"
  >
    <InfoWindow :options="{ position: center, content: 'Hello World!' }" />
    <InfoWindow :options="{ position: { lat: center.lat, lng: 150.8 } }">
      Content passed through slot
    </InfoWindow>
  </GoogleMap>
</template>
```

#### Use with Marker

You can nest the `InfoWindow` component inside the `Marker` component to display an info window when the marker is clicked.

```vue
<script setup>
import { GoogleMap, Marker, InfoWindow } from 'vue3-google-map'

const center = { lat: -25.363, lng: 131.044 }
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="4"
  >
    <Marker :options="{ position: center }">
      <InfoWindow>
        <div id="content">
          <div id="siteNotice"></div>
          <h1 id="firstHeading" class="firstHeading">Uluru</h1>
          <div id="bodyContent">
            <p><b>Uluru</b>, also referred to as <b>Ayers Rock</b>, is a large
            sandstone rock formation in the southern part of the
            Northern Territory, central Australia. It lies 335&#160;km (208&#160;mi)
            south west of the nearest large town, Alice Springs; 450&#160;km
            (280&#160;mi) by road. Kata Tjuta and Uluru are the two major
            features of the Uluru - Kata Tjuta National Park. Uluru is
            sacred to the Pitjantjatjara and Yankunytjatjara, the
            Aboriginal people of the area. It has many springs, waterholes,
            rock caves and ancient paintings. Uluru is listed as a World
            Heritage Site.</p>
            <p>Attribution: Uluru, <a href="https://en.wikipedia.org/w/index.php?title=Uluru&oldid=297882194">
            https://en.wikipedia.org/w/index.php?title=Uluru</a>
            (last visited June 22, 2009).</p>
          </div>
        </div>
      </InfoWindow>
    </Marker>
  </GoogleMap>
</template>
```

#### Open and close the Info Window

You can use `v-model` to manage the state of the info window programmatically or to know whether it's open or closed

```vue
<script setup>
import { ref, watch } from 'vue';
import { GoogleMap, Marker, InfoWindow } from 'vue3-google-map';

const center = { lat: -25.363, lng: 131.044 };
const infowindow = ref(true); // Will be open when mounted

watch(infowindow, (v) => {
  alert('infowindow has been ' + (v ? 'opened' : 'closed'));
});
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="4"
  >
    <Marker :options="{ position: center }">
      <InfoWindow v-model="infowindow">
        <div id="content">This is the infowindow content</div>
      </InfoWindow>
    </Marker>
  </GoogleMap>
</template>
```

#### Events

You can listen for [the following events](https://developers.google.com/maps/documentation/javascript/reference/info-window#InfoWindow-Events) on the `InfoWindow` component.

### Custom Marker

Regular markers can be customized a great deal but if you need to you can use the `CustomMarker` component and provide your own custom markup through it's `default` slot.

#### Options

| Parameter | Type     | Description                |
| :-------- | :------- | :------------------------- |
| `position` | `{ lat: number, lng: number}` | Sets the marker position. |
| `anchorPoint` | `'CENTER' \| 'TOP_CENTER' \|'BOTTOM_CENTER' \| 'LEFT_CENTER' \| 'RIGHT_CENTER' \| 'TOP_LEFT' \| 'TOP_RIGHT' \| 'BOTTOM_LEFT' \| 'BOTTOM_RIGHT'` | Sets how the marker is anchored relative to it's `position` point. Default is `CENTER`. |
| `offsetX` | `number` | Horizontal offset from the `position` point. |
| `offsetY` | `number` | Vertical offset from the `position` point. |
| `zIndex` | `number` | `z-index` value of the marker. |

```vue
<script setup>
import { GoogleMap, CustomMarker } from 'vue3-google-map'

const center = { lat: 52.36834, lng: 4.88635 }
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="15"
  >
    <CustomMarker :options="{ position: center, anchorPoint: 'BOTTOM_CENTER' }">
      <div style="text-align: center">
        <div style="font-size: 1.125rem">Vuejs Amsterdam</div>
        <img src="https://vuejs.org/images/logo.png" width="50" height="50" style="margin-top: 8px" />
      </div>
    </CustomMarker>
  </GoogleMap>
</template>
```

### Custom Control

Use the `CustomControl` component to add custom buttons/controls to your map.

#### Usage

You can define the markup of your custom control in the `default` slot of the `CustomControl` component. The component itself takes two props:

- `position`: Defines the position of your custom control on the map. Its value must be one of the [ControlPosition](https://developers.google.com/maps/documentation/javascript/reference/control#ControlPosition) constants.
- `index` (optional): Controls the order of placement for custom controls that occupy the same position.

Refer to the [Google Maps documentation](https://developers.google.com/maps/documentation/javascript/controls#CustomControls) on custom controls positioning.

```vue
<script setup>
import { GoogleMap, CustomControl } from 'vue3-google-map'

const center = { lat: 35, lng: -95 }
const sayHi = () => alert('Hi!')
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="13"
  >
    <CustomControl position="BOTTOM_CENTER">
      <button class="custom-btn" @click="sayHi">👋</button>
    </CustomControl>
  </GoogleMap>
</template>

<style scoped>
.custom-btn {
  box-sizing: border-box;
  background: white;
  height: 40px;
  width: 40px;
  border-radius: 2px;
  border: 0px;
  margin: 10px;
  padding: 0px;
  font-size: 1.25rem;
  text-transform: none;
  appearance: none;
  cursor: pointer;
  user-select: none;
  box-shadow: rgba(0, 0, 0, 0.3) 0px 1px 4px -1px;
  overflow: hidden;
}
</style>
```

### Marker Cluster

Use the `MarkerCluster` component to display a large number of markers on a map. It will combine markers of close proximity into clusters, and simplify the display of markers on the map. Can be used with the `Marker` or `CustomMarker` components.

#### Usage

Simply pass your `Marker`/`CustomMarker`(s) in the `default` slot of the `MarkerCluster` component.

```vue
<script setup>
import { GoogleMap, Marker, MarkerCluster } from 'vue3-google-map'

const center = { lat: -28.024, lng: 140.887 }

const locations = [
  { lat: -31.56391, lng: 147.154312 },
  { lat: -33.718234, lng: 150.363181 },
  { lat: -33.727111, lng: 150.371124 },
  { lat: -33.848588, lng: 151.209834 },
  { lat: -33.851702, lng: 151.216968 },
  { lat: -34.671264, lng: 150.863657 },
  { lat: -35.304724, lng: 148.662905 },
  { lat: -36.817685, lng: 175.699196 },
  { lat: -36.828611, lng: 175.790222 },
  { lat: -37.75, lng: 145.116667 },
  { lat: -37.759859, lng: 145.128708 },
  { lat: -37.765015, lng: 145.133858 },
  { lat: -37.770104, lng: 145.143299 },
  { lat: -37.7737, lng: 145.145187 },
  { lat: -37.774785, lng: 145.137978 },
  { lat: -37.819616, lng: 144.968119 },
  { lat: -38.330766, lng: 144.695692 },
  { lat: -39.927193, lng: 175.053218 },
  { lat: -41.330162, lng: 174.865694 },
  { lat: -42.734358, lng: 147.439506 },
  { lat: -42.734358, lng: 147.501315 },
  { lat: -42.735258, lng: 147.438 },
  { lat: -43.999792, lng: 170.463352 },
]
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="3"
  >
    <MarkerCluster>
      <Marker
        v-for="(location, i) in locations"
        :key="i"
        :options="{ position: location }"
      />
    </MarkerCluster>
  </GoogleMap>
</template>
```

#### Options

`MarkerCluster` accepts an `options` prop (an object) where you can configure `algorithm`, `onClusterClick`, and `renderer` from the [MarkerClustererOptions](https://googlemaps.github.io/js-markerclusterer/interfaces/MarkerClustererOptions.html) interface. Note that all these options are completely optional but non-reactive.

#### Events

You can listen for [the following events](https://googlemaps.github.io/js-markerclusterer/enums/MarkerClustererEvents.html) on the `MarkerCluster` component.

### Heatmap Layer

Use the `HeatmapLayer` component to depict the intensity of data at geographical points on the map. Make sure to include the `visualization` library in the `libraries` prop of the `GoogleMap` component.

#### Options

You can pass a [HeatmapLayerOptions](https://developers.google.com/maps/documentation/javascript/reference/visualization#HeatmapLayerOptions) object to the `options` prop to configure your heatmap layer. Note that for convenience you can use [LatLngLiteral](https://developers.google.com/maps/documentation/javascript/reference/coordinates#LatLngLiteral)s if you wish for the locations.

```vue
<script setup>
import { GoogleMap, HeatmapLayer } from 'vue3-google-map'

const sanFrancisco = { lat: 37.774546, lng: -122.433523 }

const heatmapData = [
  { location: { lat: 37.782, lng: -122.447 }, weight: 0.5 },
  { lat: 37.782, lng: -122.445 },
  { location: { lat: 37.782, lng: -122.443 }, weight: 2 },
  { location: { lat: 37.782, lng: -122.441 }, weight: 3 },
  { location: { lat: 37.782, lng: -122.439 }, weight: 2 },
  { lat: 37.782, lng: -122.437 },
  { location: { lat: 37.782, lng: -122.435 }, weight: 0.5 },

  { location: { lat: 37.785, lng: -122.447 }, weight: 3 },
  { location: { lat: 37.785, lng: -122.445 }, weight: 2 },
  { lat: 37.785, lng: -122.443 },
  { location: { lat: 37.785, lng: -122.441 }, weight: 0.5 },
  { lat: 37.785, lng: -122.439 },
  { location: { lat: 37.785, lng: -122.437 }, weight: 2 },
  { location: { lat: 37.785, lng: -122.435 }, weight: 3 },
]
</script>

<template>
  <GoogleMap
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    :libraries="['visualization']"
    style="width: 100%; height: 500px"
    :center="sanFrancisco"
    :zoom="13"
  >
    <HeatmapLayer :options="{ data: heatmapData }" />
  </GoogleMap>
</template>
```

## Advanced Usage

The basic components that `vue3-google-map` provides are fully reactive and will get you pretty far. Should you need to access the Google Maps API, however, the `GoogleMap` component exposes the following:

- `ready`: A boolean indicating when the Google Maps script has been loaded. By this point the map instance has been created, the API is ready for use and event listeners have been set up on the map.
- `map`: The [Map](https://developers.google.com/maps/documentation/javascript/reference/map#Map) class instance.
- `api`: The [Google Maps API](https://developers.google.com/maps/documentation/javascript/reference).
- `mapTilesLoaded`: A boolean indicating when the map tiles have been fully loaded.

In addition, most of the subcomponents expose their instance should you need it:

- `Marker` exposes `marker` (a [Marker](https://developers.google.com/maps/documentation/javascript/reference/marker#Marker) class instance).
- `Polyline` exposes `polyline` (a [Polyline](https://developers.google.com/maps/documentation/javascript/reference/polygon#Polyline) class instance).
- `Polygon` exposes `polygon` (a [Polygon](https://developers.google.com/maps/documentation/javascript/reference/polygon#Polygon) class instance).
- `Rectangle` exposes `rectangle` (a [Rectangle](https://developers.google.com/maps/documentation/javascript/reference/polygon#Rectangle) class instance).
- `Circle` exposes `circle` (a [Circle](https://developers.google.com/maps/documentation/javascript/reference/polygon#Circle) class instance).
- `InfoWindow` exposes `infoWindow` (an [InfoWindow](https://developers.google.com/maps/documentation/javascript/reference/info-window#InfoWindow) class instance).
- `MarkerCluster` exposes `markerCluster` (a [MarkerClusterer](https://googlemaps.github.io/js-markerclusterer/classes/MarkerClusterer.html) class instance).
- `HeatmapLayer` exposes `heatmapLayer` (a [HeatmapLayer](https://developers.google.com/maps/documentation/javascript/reference/visualization#HeatmapLayer) class instance).

### Usage Patterns

```vue
<script setup>
import { ref, computed, watch } from 'vue'
import { GoogleMap } from 'vue3-google-map'

const mapRef = ref(null)

// First pattern: compute some value using the API or map instance when "ready"
const markerIcon = computed(() => mapRef.value?.ready
  ? {
    url: /* icon image url */,
    scaledSize: new mapRef.value.api.Size(20, 20)
  }
  : null)

// Second pattern: watch for "ready" then do something with the API or map instance
watch(() => mapRef.value?.ready, (ready) => {
  if (!ready) return

  // do something with the api using `mapRef.value.api`
  // or with the map instance using `mapRef.value.map`
})
</script>

<template>
  <GoogleMap ref="mapRef">
    <template #default="{ ready, api, map, mapTilesLoaded }">
      <!-- Third pattern: Here you have access to the API and map instance.
      "ready" is a boolean that indicates when the Google Maps script
      has been loaded and the api and map instance are ready to be used -->
    </template>
  </GoogleMap>
</template>
```

Example:

```vue
<script setup>
import { ref, computed, watch } from 'vue'
import { GoogleMap } from 'vue3-google-map'

const mapRef = ref(null)
const center = { lat: 0, lng: 0 }

const _lng = ref(0)
const lng = computed({
  get: () => _lng.value,
  set: v => {
    if (!Number.isFinite(v)) {
      _lng.value = 0
    } else if (v > 180) {
      _lng.value = 180
    } else if (v < -180) {
      _lng.value = -180
    } else {
      _lng.value = v
    }
  },
})

watch([() => mapRef.value?.ready, lng], ([ready, lng]) => {
  if (!ready)
    return

  mapRef.value.map.panTo({ lat: 0, lng })
})
</script>

<template>
  <GoogleMap
    ref="mapRef"
    api-key="YOUR_GOOGLE_MAPS_API_KEY"
    class="map"
    :center="center"
    :zoom="2"
  />
  <label for="lng">Longitude</label>
  <input v-model.number="lng" id="lng" type="number" min="-180" max="180" step="10" />
</template>

<style scoped>
.map {
  position: relative;
  width: 100%;
  height: 500px;
}

.map::after {
  position: absolute;
  content: '';
  width: 1px;
  height: 100%;
  top: 0;
  left: 50%;
  background: red;
}

label {
  font-weight: 500;
}

input[type='number'] {
  margin-top: 20px;
  margin-left: 10px;
  outline: 1px solid #ccc;
  border-radius: 4px;
}
</style>
```

### Loading the Google Maps API script externally

By default you would pass your API key as a prop to the `GoogleMap` component and it handles the loading of the Google Maps API script for you. There are cases, however, where you might want to load the script yourself. For example, you might be using other Google Maps components or your Vue app might be a part of a larger app that uses the Google Maps API elsewhere. In these cases you can use the `apiPromise` prop to pass a promise that resolves to the Google Maps API global `google` object.

```vue
<script setup>
import { GoogleMap, Marker } from 'vue3-google-map';
import { Loader } from '@googlemaps/js-api-loader';

const loader = new Loader({
  apiKey: '',
  version: 'weekly',
  libraries: ['places'],
});

const apiPromise = loader.load();

const center = { lat: 40.689247, lng: -74.044502 };
</script>

<template>
  <GoogleMap
    :api-promise="apiPromise"
    style="width: 100%; height: 500px"
    :center="center"
    :zoom="15"
  >
    <Marker :options="{ position: center }" />
  </GoogleMap>
</template>
```

## Contribution

All contributions are welcome. Before submitting a PR though it would be nice if you created an issue explaining what you want to acheive and why.

## License

[MIT](http://opensource.org/licenses/MIT)