Geolocation

Geolocation

The geolocation object provides access to location data based on the device's GPS sensor or inferred from network signals.

This plugin provides information about the device's location, such as latitude and longitude. Common sources of location information include Global Positioning System (GPS) and location inferred from network signals such as IP address, RFID, WiFi and Bluetooth MAC addresses, and GSM/CDMA cell IDs. There is no guarantee that the API returns the device's actual location.

This API is based on the W3C Geolocation API Specification, and only executes on devices that don't already provide an implementation.

WARNING: Collection and use of geolocation data raises important privacy issues. Your app's privacy policy should discuss how the app uses geolocation data, whether it is shared with any other parties, and the level of precision of the data (for example, coarse, fine, ZIP code level, etc.). Geolocation data is generally considered sensitive because it can reveal user's whereabouts and, if stored, the history of their travels. Therefore, in addition to the app's privacy policy, you should strongly consider providing a just-in-time notice before the app accesses geolocation data (if the device operating system doesn't do so already). That notice should provide the same information noted above, as well as obtaining the user's permission (e.g., by presenting choices for OK and No Thanks). For more information, please see the Privacy Guide.

Methods

Arguments

Objects (Read-Only)

Supported Platforms

  • Android
  • iOS

geolocation.getCurrentPosition

Returns the device's current position to the geolocationSuccess callback with a Position object as the parameter. If there is an error, the geolocationError callback is passed a PositionError object.

navigator.geolocation.getCurrentPosition(geolocationSuccess,
                                         [geolocationError],
                                         [geolocationOptions]);

Parameters

Example

// onSuccess Callback
// This method accepts a Position object, which contains the
// current GPS coordinates
//
var onSuccess = function(position) {
    alert('Latitude: '          + position.coords.latitude          + '\n' +
          'Longitude: '         + position.coords.longitude         + '\n' +
          'Altitude: '          + position.coords.altitude          + '\n' +
          'Accuracy: '          + position.coords.accuracy          + '\n' +
          'Altitude Accuracy: ' + position.coords.altitudeAccuracy  + '\n' +
          'Heading: '           + position.coords.heading           + '\n' +
          'Speed: '             + position.coords.speed             + '\n' +
          'Timestamp: '         + position.timestamp                + '\n');
};

// onError Callback receives a PositionError object
//
function onError(error) {
    alert('code: '    + error.code    + '\n' +
          'message: ' + error.message + '\n');
}

navigator.geolocation.getCurrentPosition(onSuccess, onError);

geolocation.watchPosition

Returns the device's current position when a change in position is detected. When the device retrieves a new location, the geolocationSuccess callback executes with a Position object as the parameter. If there is an error, the geolocationError callback executes with a PositionError object as the parameter.

var watchId = navigator.geolocation.watchPosition(geolocationSuccess,
                                                  [geolocationError],
                                                  [geolocationOptions]);

Parameters

Returns

  • String: returns a watch id that references the watch position interval. The watch id should be used with navigator.geolocation.clearWatch to stop watching for changes in position.

Example

// onSuccess Callback
//   This method accepts a `Position` object, which contains
//   the current GPS coordinates
//
function onSuccess(position) {
    var element = document.getElementById('geolocation');
    element.innerHTML = 'Latitude: '  + position.coords.latitude      + '<br />' +
                        'Longitude: ' + position.coords.longitude     + '<br />' +
                        '<hr />'      + element.innerHTML;
}

// onError Callback receives a PositionError object
//
function onError(error) {
    alert('code: '    + error.code    + '\n' +
          'message: ' + error.message + '\n');
}

// Options: throw an error if no update is received every 30 seconds.
//
var watchID = navigator.geolocation.watchPosition(onSuccess, onError, { timeout: 30000 });

geolocation.clearWatch

Stop watching for changes to the device's location referenced by the watchID parameter.

navigator.geolocation.clearWatch(watchID);

Parameters

  • watchID: The id of the watchPosition interval to clear. (String)

Example

// Options: watch for changes in position, and use the most
// accurate position acquisition method available.
//
var watchID = navigator.geolocation.watchPosition(onSuccess, onError, { enableHighAccuracy: true });

// ...later on...

navigator.geolocation.clearWatch(watchID);

Coordinates

A Coordinates object is attached to a Position object that is available to callback functions in requests for the current position. It contains a set of properties that describe the geographic coordinates of a position.

Properties

  • latitude: Latitude in decimal degrees. (Number)

  • longitude: Longitude in decimal degrees. (Number)

  • altitude: Height of the position in meters above the ellipsoid. (Number)

  • accuracy: Accuracy level of the latitude and longitude coordinates in meters. (Number)

  • altitudeAccuracy: Accuracy level of the altitude coordinate in meters. (Number)

  • heading: Direction of travel, specified in degrees counting clockwise relative to the true north. (Number)

  • speed: Current ground speed of the device, specified in meters per second. (Number)

Android Quirks

altitudeAccuracy: Not supported by Android devices, returning null.


Position

Contains Position coordinates and timestamp, created by the geolocation API.

Properties

  • coords: A set of geographic coordinates. (Coordinates)

  • timestamp: Creation timestamp for coords. (Date)


PositionError

The PositionError object is passed to the geolocationError callback function when an error occurs with navigator.geolocation.

Properties

  • code: One of the predefined error codes listed below.

  • message: Error message describing the details of the error encountered.

Constants

  • PositionError.PERMISSION_DENIED
    • Returned when users do not allow the app to retrieve position information. This is dependent on the platform.
  • PositionError.POSITION_UNAVAILABLE
    • Returned when the device is unable to retrieve a position. In general, this means the device is not connected to a network or can't get a satellite fix.
  • PositionError.TIMEOUT

PositionError.PERMISSION_DENIED

Returned when the user does not allow your application to retrieve position information. This is dependent on the platform.

PositionError.POSITION_UNAVAILABLE

Returned when the device is unable to retrieve a position. In general this means the device has no network connectivity and/or cannot get a satellite fix.

PositionError.TIMEOUT

Returned when the device is unable to retrieve a position within the time specified in the geolocationOptions' timeout property. When used with geolocation.watchPosition, this error could be passed to the geolocationError callback every timeout milliseconds.


geolocationSuccess

The user's callback function that executes when a geolocation position becomes available (when called from geolocation.getCurrentPosition), or when the position changes (when called from geolocation.watchPosition).

function(position) {
    // Do something
}

Parameters

  • position: The geolocation position returned by the device. (Position)

Example

function geolocationSuccess(position) {
    alert('Latitude: '          + position.coords.latitude          + '\n' +
          'Longitude: '         + position.coords.longitude         + '\n' +
          'Altitude: '          + position.coords.altitude          + '\n' +
          'Accuracy: '          + position.coords.accuracy          + '\n' +
          'Altitude Accuracy: ' + position.coords.altitudeAccuracy  + '\n' +
          'Heading: '           + position.coords.heading           + '\n' +
          'Speed: '             + position.coords.speed             + '\n' +
          'Timestamp: '         + position.timestamp                + '\n');
}

geolocationError

The user's callback function that executes when there is an error for geolocation functions.

function(error) {
    // Handle the error
}

Parameters


geolocationOptions

Optional parameters to customize the retrieval of the geolocation Position.

{ maximumAge: 3000, timeout: 5000, enableHighAccuracy: true };

Options

  • enableHighAccuracy: Provides a hint that the application needs the best possible results. By default, the device attempts to retrieve a Position using network-based methods. Setting this property to true tells the framework to use more accurate methods, such as satellite positioning. (Boolean)

  • timeout: The maximum length of time (milliseconds) that is allowed to pass from the call to navigator.geolocation.getCurrentPosition or geolocation.watchPosition until the corresponding geolocationSuccess callback executes. If the geolocationSuccess callback is not invoked within this time, the geolocationError callback is passed a PositionError.TIMEOUT error code. (Note that when used in conjunction with geolocation.watchPosition, the geolocationError callback could be called on an interval every timeout milliseconds!) (Number)

  • maximumAge: Accept a cached position whose age is no greater than the specified time in milliseconds. (Number)

Android Quirks

Android 2.x emulators do not return a geolocation result unless the enableHighAccuracy option is set to true.