auto-complete.js

// This sample uses the Autocomplete widget to help the user select a
// place, then it retrieves the address components associated with that
// place, and then it populates the form fields with those details.
// This sample requires the Places library. Include the libraries=places
// parameter when you first load the API. For example:
// <script
// src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=places">
let placeSearch;
let autocomplete;
const componentForm = {
  street_number: "short_name",
  route: "long_name",
  locality: "long_name",
  administrative_area_level_1: "short_name",
  country: "long_name",
  postal_code: "short_name",
};

function initAutocomplete() {
  // Create the autocomplete object, restricting the search predictions to
  // geographical location types.
  autocomplete = new google.maps.places.Autocomplete(
    document.getElementById("autocomplete"),
    { types: ["geocode"] }
  );
  // Avoid paying for data that you don't need by restricting the set of
  // place fields that are returned to just the address components.
  autocomplete.setFields(["address_component"]);
  // When the user selects an address from the drop-down, populate the
  // address fields in the form.
  autocomplete.addListener("place_changed", fillInAddress);
}

function fillInAddress() {
  // Get the place details from the autocomplete object.
  const place = autocomplete.getPlace();

  for (const component in componentForm) {
    document.getElementById(component).value = "";
    document.getElementById(component).disabled = false;
  }

  // Get each component of the address from the place details,
  // and then fill-in the corresponding field on the form.
  for (const component of place.address_components) {
    const addressType = component.types[0];

    if (componentForm[addressType]) {
      const val = component[componentForm[addressType]];
      document.getElementById(addressType).value = val;
    }
  }
}

// Bias the autocomplete object to the user's geographical location,
// as supplied by the browser's 'navigator.geolocation' object.
function geolocate() {
  if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition((position) => {
      const geolocation = {
        lat: position.coords.latitude,
        lng: position.coords.longitude,
      };
      const circle = new google.maps.Circle({
        center: geolocation,
        radius: position.coords.accuracy,
      });
      autocomplete.setBounds(circle.getBounds());
    });
  }
}