Example for google map with vue.js without vue library
Tags: javascript, vue
Published: 2018-03-05 14:22:23

---
title: Example for google map with vue.js without vue library
published: true
description: 
tags: javascript, vue.js
---

I want use google map in vue.js.
It's enable when use like vue2-google-map library, but I want more directry use google API.

# Output
Demo: https://vue-google-map-provider-sample.netlify.com/
Source: https://github.com/inuscript/example-vue-inject-provide-google-map

# Implements
I create those components.

* index.html 
* MyMap.vue (Map parent. Combine some components)
* MapLoader.vue (Only process Google Map callback）
* MapProvider.vue (Only use vue.js `provide`）
* ChildMarker.vue (Example for `marker` child element）

## index.html

```html
    <!-- index.html -->
    <div id="app">
      <my-map :markers='[
        {"lat":35.6432027,"lng":139.6729435},
        {"lat":35.5279833,"lng":139.6989209},
        {"lat":35.6563623,"lng":139.7215211},
        {"lat":35.6167531,"lng":139.5469376},
        {"lat":35.6950961,"lng":139.5037899}
      ]'>
      </my-map>
    </div>
```

It is commonly `index.html`

## MyMap.vue

Component parent example (not so important).

```html
<!-- MyMap.vue -->
<template>
  <div>
    <h1>Map</h1>
    <map-loader 
      :map-config="mapConfig"
      apiKey="YOUR API KEY"
    >
      <template v-for="marker in markers">
        <child-marker :position="marker" />
      </template>
    </map-loader>
  </div>
</template>

<script>
import MapLoader from "./MapLoader.vue"
import ChildMarker from './ChildMarker'

export default {
  props: {
    markers: Array
  },
  data(){
    return {
      mapConfig: {
        zoom: 12,
        center: this.markers[0]
      }
    }
  },
  components: {
    MapLoader,
    ChildMarker
  }
}
</script>
```

This call `map-loader`, and use `child-marker` in internal.

## MapLoader

This is the most core implementations (part 1).

```html
<!-- MapLoader.vue -->
<template>
  <div>
    <div id="map"></div> <!-- point 1 -->
    <template v-if="!!this.google && !!this.map"> <!-- point 2 -->
      <map-provider
        :google="google"
        :map="map"
      >
        <slot/>
      </map-provider>
    </template>
  </div>
</template>

<script>
import GoogleMapsApiLoader from 'google-maps-api-loader'
import MapProvider from './MapProvider'

export default {
  props:{
    mapConfig: Object,
    apiKey: String
  },
  components: {
    MapProvider
  },
  data(){
    return {
      google: null,
      map: null
    }
  },
  mounted () { // point 3
    GoogleMapsApiLoader({
      apiKey: this.apiKey
    }).then((google) => {
      this.google = google
      this.initializeMap()
    })
  },
  methods: {
    initializeMap (){
      const mapContainer = this.$el.querySelector('#map') // point 1
      const { Map } = this.google.maps
      this.map = new Map(mapContainer, this.mapConfig)
    }
  }
}
</script>

<style scoped>
#map {
  height: 100vh;
  width: 100%;
}
</style>
```

This component some points.

* point 1: This use `#map` and raw DOM. and after it mount with `this.$el`
* point 2: Core of core. This **suspend** mount children until `google` or `map` value is valid. This make can use `provide/inject`.
* point 3: Call `GoogleMapApiLoader` when `mounted()` lifecycle is called.


## MapProvider
Core Implementation (part 2)
This setting `provide` and pass children to `google` and `map` value.

Vue's `provide` is evaluate only first time. 
If set `provide` on `map-loader`, `google` and `map` value may null value and it's not update.

In this implementation, `map-loader` pass evaluated `google` and `map` value, `map-provider` can valid value.

```html
<!-- MapProvider.vue -->
<template>
  <div>
    <slot />
  </div>
</template>

<script>
export default {
  props: {
    google: Object,
    map: Object,
  },
  provide() {
    return {
      google: this.google,
      map: this.map
    }
  },
}
</script>
```

## ChildMarker

```html
<!-- ChildMarker.vue -->
<template></template>
<script>
export default {
  inject: ["google", "map"],
  props: {
    position: Object
  },
  data(){
    return { marker: null}
  },
  mounted(){
    const { Marker } = this.google.maps
    this.marker = new Marker({
      position: this.position,
      map: this.map,
      title: "Child marker!"
    })
  }
}
</script>

```

Example for Marker child.
It's use `inject` and use `mounted()` same as `MapLoader`


# Don't use provide/inject pattern (use slot-scope)

In official document, `provide / inject` is not recommended generic application.

If don't use `provide / inject`, we must pass values to children.
In this implementation, we need `slot-scope` too.



`MapLoader` remove `MapProvider`, and pass `google` and `map` to `slot`

```html
<!-- MapLoader.vue -->
<template>
  <div>
    <div id="map"></div>
    <template v-if="!!this.google && !!this.map">
      <slot
        :google="google"
        :map="map"
      />
    </template>
  </div>
</template>

<script>
 :
</script>
```

Next, in `MyApp`, use `slot-scope` and pass value to `child-marker`

```html
<!-- MyMap -->
<template>
  <div>
    <h1>Map</h1>
    <map-loader 
      :map-config="mapConfig"
      apiKey="YOUR API KEY">
      <template slot-scope="scopeProps"> <!-- slot-scope -->
        <child-marker 
          v-for="(marker,i) in markers"
          :key="i"
          :position="marker" 
          :google="scopeProps.google"
          :map="scopeProps.map"
        />
      </template>
    </map-loader>
  </div>
</template>
```

`ChildMarker` remove `inject` and got value with `props`.

```html
<!-- ChildMarker -->
<template></template>
<script>
export default {
  props: {
    google: Object,
    map: Object,
    position: Object
  },
  data(){
    return { marker: null }
  },
  mounted(){
    const { Marker } = this.google.maps
    this.marker = new Marker({
      position: this.position,
      map: this.map,
      title: "Child marker!"
    })
  }
}
</script>
```