Place Autocomplete Data Sessions

Page Summary

• This example demonstrates using the Place Autocomplete data to provide a list of place predictions based on user input.

• When a prediction is selected, further details about the place are displayed, including its name and address.

• This sample utilizes an AutocompleteSessionToken to manage the autocomplete session for optimized results.

• The example is implemented using both TypeScript and JavaScript, providing flexibility for developers.

This example takes user input and displays a list of place predictions. When a selection is made place details are retrieved, a marker is displayed, and the session is concluded.

The following concepts are demonstrated:

• Calling fetchAutocompleteSuggestions()
• Using session tokens to group a user query with the final Place Details request. based on user queries and showing a list of predicted places in response.
• Retrieving place details for the selected place and displaying a marker.
• Using control slotting to nest UI elements in the gmp-map element.

Read the documentation.

TypeScript

const mapElement = document.querySelector('gmp-map')!;
let innerMap: google.maps.Map;
let marker: google.maps.marker.AdvancedMarkerElement;
const titleElement = document.querySelector<HTMLElement>('.title')!;
const resultsContainerElement = document.querySelector('.results')!;
const inputElement = document.querySelector('input')!;
const tokenStatusElement = document.querySelector('.token-status')!;
let newestRequestId = 0;
let tokenCount = 0;

// Create an initial request body.
const request: google.maps.places.AutocompleteRequest = {
    input: '',
    includedPrimaryTypes: [
        'restaurant',
        'cafe',
        'museum',
        'park',
        'botanical_garden',
    ],
};

async function init() {
    await google.maps.importLibrary('maps');
    innerMap = mapElement.innerMap;
    innerMap.setOptions({
        mapTypeControl: false,
    });

    // Update request center and bounds when the map bounds change.
    innerMap.addListener('bounds_changed', () => {
        request.locationRestriction = innerMap.getBounds();
        request.origin = innerMap.getCenter();
    });

    inputElement.addEventListener('input', makeAutocompleteRequest);
}

async function makeAutocompleteRequest(inputEvent: Event) {
    // To avoid race conditions, store the request ID and compare after the request.
    const requestId = ++newestRequestId;

    const { AutocompleteSuggestion } =
        await google.maps.importLibrary('places');

    if (!(inputEvent.target as HTMLInputElement)?.value) {
        titleElement.textContent = '';
        resultsContainerElement.replaceChildren();
        return;
    }

    // Add the latest char sequence to the request.
    request.input = (inputEvent.target as HTMLInputElement).value;

    // Fetch autocomplete suggestions and show them in a list.
    const { suggestions } =
        await AutocompleteSuggestion.fetchAutocompleteSuggestions(request);

    // If the request has been superseded by a newer request, do not render the output.
    if (requestId !== newestRequestId) return;

    titleElement.innerText = `Place predictions for "${request.input}"`;

    // Clear the list first.
    resultsContainerElement.replaceChildren();

    for (const suggestion of suggestions) {
        const placePrediction = suggestion.placePrediction;

        if (!placePrediction) {
            continue;
        }

        // Create a link for the place, add an event handler to fetch the place.
        // We are using a button element to take advantage of its a11y capabilities.
        const placeButton = document.createElement('button');
        placeButton.addEventListener('click', () => {
            void onPlaceSelected(placePrediction.toPlace());
        });

        placeButton.textContent = placePrediction.text.toString();
        placeButton.classList.add('place-button');

        // Create a new list item element.
        const li = document.createElement('li');
        li.appendChild(placeButton);
        resultsContainerElement.appendChild(li);
    }
}

// Event handler for clicking on a suggested place.
async function onPlaceSelected(place: google.maps.places.Place) {
    const { AdvancedMarkerElement } = await google.maps.importLibrary('marker');

    await place.fetchFields({
        fields: ['displayName', 'formattedAddress', 'location'],
    });

    resultsContainerElement.textContent = `${place.displayName}: ${place.formattedAddress}`;
    titleElement.textContent = 'Selected Place:';
    inputElement.value = '';

    await refreshToken();

    // Remove the previous marker, if it exists.
    if (marker) {
        marker.remove();
    }

    // Create a new marker.
    marker = new AdvancedMarkerElement({
        map: innerMap,
        position: place.location,
        title: place.displayName,
    });

    // Center the map on the selected place.
    if (place.location) {
        innerMap.setCenter(place.location);
        innerMap.setZoom(15);
    }
}

// Helper function to refresh the session token.
async function refreshToken() {
    const { AutocompleteSessionToken } =
        await google.maps.importLibrary('places');

    // Increment the token counter.
    tokenCount++;

    // Create a new session token and add it to the request.
    request.sessionToken = new AutocompleteSessionToken();
    tokenStatusElement.textContent = `Session token count: ${tokenCount}`;
}

void init();
index.ts

Note: Read the guide on using TypeScript and Google Maps.

JavaScript

const mapElement = document.querySelector('gmp-map');
let innerMap;
let marker;
const titleElement = document.querySelector('.title');
const resultsContainerElement = document.querySelector('.results');
const inputElement = document.querySelector('input');
const tokenStatusElement = document.querySelector('.token-status');
let newestRequestId = 0;
let tokenCount = 0;

// Create an initial request body.
const request = {
    input: '',
    includedPrimaryTypes: [
        'restaurant',
        'cafe',
        'museum',
        'park',
        'botanical_garden',
    ],
};

async function init() {
    await google.maps.importLibrary('maps');
    innerMap = mapElement.innerMap;
    innerMap.setOptions({
        mapTypeControl: false,
    });

    // Update request center and bounds when the map bounds change.
    innerMap.addListener('bounds_changed', () => {
        request.locationRestriction = innerMap.getBounds();
        request.origin = innerMap.getCenter();
    });

    inputElement.addEventListener('input', makeAutocompleteRequest);
}

async function makeAutocompleteRequest(inputEvent) {
    // To avoid race conditions, store the request ID and compare after the request.
    const requestId = ++newestRequestId;

    const { AutocompleteSuggestion } =
        await google.maps.importLibrary('places');

    if (!inputEvent.target?.value) {
        titleElement.textContent = '';
        resultsContainerElement.replaceChildren();
        return;
    }

    // Add the latest char sequence to the request.
    request.input = inputEvent.target.value;

    // Fetch autocomplete suggestions and show them in a list.
    const { suggestions } =
        await AutocompleteSuggestion.fetchAutocompleteSuggestions(request);

    // If the request has been superseded by a newer request, do not render the output.
    if (requestId !== newestRequestId) return;

    titleElement.innerText = `Place predictions for "${request.input}"`;

    // Clear the list first.
    resultsContainerElement.replaceChildren();

    for (const suggestion of suggestions) {
        const placePrediction = suggestion.placePrediction;

        if (!placePrediction) {
            continue;
        }

        // Create a link for the place, add an event handler to fetch the place.
        // We are using a button element to take advantage of its a11y capabilities.
        const placeButton = document.createElement('button');
        placeButton.addEventListener('click', () => {
            void onPlaceSelected(placePrediction.toPlace());
        });

        placeButton.textContent = placePrediction.text.toString();
        placeButton.classList.add('place-button');

        // Create a new list item element.
        const li = document.createElement('li');
        li.appendChild(placeButton);
        resultsContainerElement.appendChild(li);
    }
}

// Event handler for clicking on a suggested place.
async function onPlaceSelected(place) {
    const { AdvancedMarkerElement } = await google.maps.importLibrary('marker');

    await place.fetchFields({
        fields: ['displayName', 'formattedAddress', 'location'],
    });

    resultsContainerElement.textContent = `${place.displayName}: ${place.formattedAddress}`;
    titleElement.textContent = 'Selected Place:';
    inputElement.value = '';

    await refreshToken();

    // Remove the previous marker, if it exists.
    if (marker) {
        marker.remove();
    }

    // Create a new marker.
    marker = new AdvancedMarkerElement({
        map: innerMap,
        position: place.location,
        title: place.displayName,
    });

    // Center the map on the selected place.
    if (place.location) {
        innerMap.setCenter(place.location);
        innerMap.setZoom(15);
    }
}

// Helper function to refresh the session token.
async function refreshToken() {
    const { AutocompleteSessionToken } =
        await google.maps.importLibrary('places');

    // Increment the token counter.
    tokenCount++;

    // Create a new session token and add it to the request.
    request.sessionToken = new AutocompleteSessionToken();
    tokenStatusElement.textContent = `Session token count: ${tokenCount}`;
}

void init();
index.js

CSS

/* 
 * Always set the map height explicitly to define the size of the div element
 * that contains the map. 
 */
gmp-map {
    height: 100%;
}

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
    height: 100%;
    margin: 0;
    padding: 0;
}

.place-button {
    height: 3rem;
    width: 100%;
    background-color: transparent;
    text-align: left;
    border: none;
    cursor: pointer;
}

.place-button:focus-visible {
    outline: 2px solid #0056b3;
    border-radius: 2px;
}

.input {
    width: 300px;
    font-size: small;
    margin-bottom: 1rem;
}

/* Styles for the floating panel */
.controls {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
    font-family: sans-serif;
    font-size: small;
    margin: 12px;
    padding: 1rem;
}

.title {
    font-weight: bold;
    margin-top: 1rem;
    margin-bottom: 0.5rem;
}

.results {
    list-style-type: none;
    margin: 0;
    padding: 0;
}

.results li:not(:last-child) {
    border-bottom: 1px solid #ddd;
}

.results li:hover {
    background-color: #eee;
}
style.css

HTML

<html>
    <head>
        <title>Place Autocomplete Data API Session</title>

        <link rel="stylesheet" type="text/css" href="./style.css" />
        <script type="module" src="./index.js"></script>
        <script>
            // prettier-ignore
            (g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})({
                key: "GOOGLE_MAPS_API_KEY"
            });
        </script>
    </head>
    <body>
        <gmp-map center="37.7893, -122.4039" zoom="12" map-id="DEMO_MAP_ID">
            <div class="controls" slot="control-inline-start-block-start">
                <input
                    type="text"
                    class="input"
                    placeholder="Search for a place..."
                    autocomplete="off" /><!-- Turn off the input's own autocomplete (not supported by all browsers).-->
                <div class="token-status"></div>
                <div class="title"></div>
                <ol class="results"></ol>
            </div>
        </gmp-map>
    </body>
</html>
index.html

Clone Sample

Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. You will also need a Google Maps API key.

The following commands clone the repository, install dependencies, and copy the environment file.

  git clone https://github.com/googlemaps-samples/js-api-samples.git
  cd js-api-samples
  npm i
  cp .env.template .env

Once you copy the environment file, make sure to open the .env file and replace <Insert your own development API key here> with your actual API key before starting the sample.

  cd samples/place-autocomplete-data-session
  npm start