😎 Implement Google Maps Autocomplete API | Vue.js

#vue #javascript

This tutorial explains how you can easily implement a Places Autocomplete Service by Google Maps API in vue.js

NOTE: the picture is fancy because I use VUETIFY. This tutorial just explains how Google Places API work, with no CSS! 😐

Checkout this video for a demo

All we need is a vue component and a plugin called vue-meta (I already use it for SEO)

First let’s create a file called `Places.vue`

// Places.vue

<template>
  <div>
    <input type="text" v-model="location">
    <ul>
      <li v-for="(result, i) in searchResults" :key="i">
        {{ result }} // list of all places
      </li>
    </ul>
  </div>
</template>

Now add a script tag in the same file and add the following -

// Places.vue

<script>
  export default {
    data: () => ({
      location: '',
      searchResults: [],
      service: null // will reveal this later 🕵️
    })
  }
</script>

Install vue-meta plugin — the documentation is very easy and the plugin is installed like any other vue plugin.

Putting the metaInfo hook in Places.vue -

// Places.vue

<script>
  export default {
    data, // already wrote above
    metaInfo () {
      return {
        script: [{
          src: `https://maps.googleapis.com/maps/api/js?key=<YOUR_API_KEY>&libraries=places`,
          async: true,
          defer: true,
          callback: () => this.MapsInit() // will declare it in methods
        }]
      }
    }
  }
</script>

So the reason I used metaInfo here is because we can -

Download external JS files on the go, only when the component is rendered.
It gives us the power of the callback function, called when the JS file is downloaded! — 😎

Now let’s move ahead and create the most awaited methods hook -

// Places.vue

<script>
  export default {
    data // defined already,
    metaInfo // defined already,

    methods: {
      MapsInit () {
        this.service = new window.google.maps.places.AutocompleteService()
      },
      displaySuggestions (predictions, status) {
        if (status !== window.google.maps.places.PlacesServiceStatus.OK) {
          this.searchResults = []
          return
        }
        this.searchResults = predictions.map(prediction => prediction.description) 
      }
    }

  }
</script>

Let's see what these functions MapsInit and displaySuggestions do.

MapInit() - the function that is called when the JS file is loaded.

In this we use a google places service called - AutocompleteService (Don't bother right now! Check google documentation if you can't live without it 🤷).

we assign this AutocompleteService() to our data property 'service' so that we can use it again later.

displaySuggestions(predictions, status) - explained a little later.

And this is the last piece of the puzzle. The watcher on the location property

// Places.vue

<script>
  export default {
    data // already defined,
    methods // already defined,
    metaInfo // already defined,
    // the magical part
    watch: {
      location (newValue) {
        if (newValue) {
          this.service.getPlacePredictions({
            input: this.location,
            types: ['(cities)']
          }, this.displaySuggestions)
        }
      }
    }
  }
</script>

So, whatever you type in the input field changes the location property, and whenever the location property is changed, a getPlacePredictions function is called that is attached to the service property.

getPlacePredictions receives two parameters-

An Object that has many things but we only use input and types here-
a. input - the query to be predicted (this.locations in our case).
b. types - the type of result.
the callback function we declared above in methods hook which is - displaySuggestions.

All done!

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Top comments (15)

CodeBreaker • Jan 16 '22

Since GMAP script tag is added via vue meta and is also responsible for calling MapInit (which is setting the service data), if the component re-mounts or the user briefly navigates away, service will become NULL and the api will stop working.

Oliver Kelso • Mar 1 '22

I believe this is true. This is why also it seems, adding more than one of these components to a page won't work, and the service never gets set, and stays null.

francisjr1997 • Mar 2 '22

Yes, I'm facing the same issue as well. Did you solve it?

Oliver Kelso • Mar 3 '22

I did. I just had to change when initmap was called. I think I set a check for it in the watcher for location. When I get back home, I'll double check.

Oliver Kelso • Mar 3 '22 • Edited

So this maybe not the best solution, and there maybe a better a way, but it was done quickly, as I'm still working on this. Here is a gist of the component I have right now. There is a bunch of irrelevant stuff in it for this, but at least it gives you an idea of what I did.

gist.github.com/pixelsoul/8b854e39...