The record's this object exposes the GPS location captured at the moment the feature (record or repeatable item) was most recently updated on the mobile device. These four properties give you access to that update-time snapshot: latitude, longitude, altitude, and horizontal accuracy.

For a feature that has never been edited after creation, these values will match the corresponding featureCreated* properties.

These properties are available in both calculation fields and data events.

this.featureUpdatedLatitude

Returns the latitude recorded at the time the feature was most recently updated.

Syntax

this.featureUpdatedLatitude

Returns

Number — Decimal degrees (WGS84). Returns null if no GPS fix was available at the time of the update, or if the feature was updated from the web.

Examples

// Return the update latitude
this.featureUpdatedLatitude
// returns 27.771203451892

// Approximate local distance, scaling longitude by the cosine of mean latitude
var createdLat = this.featureCreatedLatitude;
var createdLon = this.featureCreatedLongitude;
var updatedLat = this.featureUpdatedLatitude;
var updatedLon = this.featureUpdatedLongitude;

if (createdLat !== null && createdLon !== null &&
    updatedLat !== null && updatedLon !== null) {
  var meanLat = ((createdLat + updatedLat) / 2) * Math.PI / 180;
  var latMeters = (updatedLat - createdLat) * 111320;
  var lonDiff = updatedLon - createdLon;
  if (lonDiff > 180) {
    lonDiff -= 360;
  } else if (lonDiff < -180) {
    lonDiff += 360;
  }
  var lonMeters = lonDiff * 111320 * Math.cos(meanLat);
  var approxMeters = Math.sqrt(latMeters * latMeters + lonMeters * lonMeters);
  SETRESULT(ROUND(approxMeters, 1) + 'm');
} else {
  SETRESULT('Distance unavailable');
}

This equirectangular approximation accounts for the shorter east-west distance at higher latitudes and is intended for local distances.

Notes

• Returns null for records updated on the Fulcrum web app.
• Returns null if the device did not have a GPS fix at the time of the update.
• For a newly created feature that has not yet been edited, this value matches this.featureCreatedLatitude.
• For repeatable items, reflects the GPS location of the repeatable at the time of the most recent save.

this.featureUpdatedLongitude

Returns the longitude recorded at the time the feature was most recently updated.

Syntax

this.featureUpdatedLongitude

Returns

Number — Decimal degrees (WGS84). Returns null if no GPS fix was available at the time of the update, or if the feature was updated from the web.

Examples

// Return the update longitude
this.featureUpdatedLongitude
// returns -82.637204

// Display updated coordinates as a formatted string
'Last updated at: ' + this.featureUpdatedLatitude + ', ' + this.featureUpdatedLongitude
// returns "Last updated at: 27.771203451892, -82.637204"

Notes

• Returns null for records updated on the Fulcrum web app.
• Returns null if the device did not have a GPS fix at the time of the update.
• For a newly created feature that has not yet been edited, this value matches this.featureCreatedLongitude.

this.featureUpdatedAltitude

Returns the altitude (in meters above sea level) recorded at the time the feature was most recently updated.

Syntax

this.featureUpdatedAltitude

Returns

Number — Meters above sea level (WGS84 ellipsoid). Returns null if altitude data was unavailable at the time of the update, or if the feature was updated from the web.

Examples

// Return the update altitude
this.featureUpdatedAltitude
// returns 29.112456

// Show elevation change between creation and last update
var updatedAltitude = this.featureUpdatedAltitude;
var createdAltitude = this.featureCreatedAltitude;

if (updatedAltitude === null || createdAltitude === null) {
  SETRESULT('Altitude unavailable');
} else {
  var gain = updatedAltitude - createdAltitude;
  SETRESULT(ROUND(gain, 2) + 'm elevation change');
}
// returns "1.34m elevation change" or "Altitude unavailable"

Notes

• Returns null if the device hardware does not support altitude or no GPS fix was available at the time of update.
• Returns null for records updated on the Fulcrum web app.
• For a newly created feature that has not yet been edited, this value matches this.featureCreatedAltitude.

this.featureUpdatedAccuracy

Returns the horizontal GPS accuracy (in meters) recorded at the time the feature was most recently updated.

Syntax

this.featureUpdatedAccuracy

Returns

Number — Meters. A lower value indicates a more precise GPS fix. Returns null if accuracy data was unavailable at the time of the update, or if the feature was updated from the web.

Examples

// Return the update GPS accuracy
this.featureUpdatedAccuracy
// returns 4.8

// Prevent saving if GPS accuracy at update is too poor
ON('save-record', function(event) {
  var accuracy = this.featureUpdatedAccuracy;
  if (accuracy !== null && accuracy > 20) {
    INVALID('GPS uncertainty is too high (' + accuracy + 'm). Move to an open area and try again.');
  }
});

Notes

• Returns null for records updated on the Fulcrum web app.
• Returns null if accuracy data was not available at the time of the update.
• For a newly created feature that has not yet been edited, this value matches this.featureCreatedAccuracy.