traccar

An utility function library for extracting geometries from Traccar positions and geofences.

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traccar.traccarPositionToGeoJSON(traccarPosition)

traccarPositionToGeoJSON(OBJECT traccarPosition): Converts a Traccar position object to a GeoJSON string representing a Point. The function expects a Traccar position object as input, which must contain at least the latitude and longitude fields. If the position object also contains an altitude field, this will be included in the GeoJSON output. The output GeoJSON will also include the WGS84 CRS (Coordinate Reference System) as “EPSG:4326”.

Example:

policy "example"
permit
where
    var position = {
        "id": 123,
        "deviceId": 456,
        "type": "position",
        "protocol": "h02",
        "latitude": 37.7749,
        "longitude": -122.4194,
        "altitude": 100.0,
        "speed": 0.0,
        "course": 0.0,
        "accuracy": 5.0,
        "timestamp": "2024-03-08T12:00:00Z",
        "serverTime": "2024-03-08T12:00:05Z",
        "valid": true,
        "attributes": {
          "battery": 95.5,
          "motion": false
          }
    };
    traccar.traccarPositionToGeoJSON(position) == '{"type":"Point","coordinates":[-122.4194,37.7749,100.0],"crs":{"type":"name","properties":{"name":"EPSG:4326"}}}';

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traccar.traccarGeofenceToGeoJson(geofence)

traccarGeofenceToGeoJson(OBJECT geofence): Converts a Traccar geofence object to a GeoJSON string representing the geofence’s geometry. The function expects a Traccar geofence object as input, which must contain an area field. The area field represents the geofence’s geometry in Well-Known Text (WKT) format. The function will flip the coordinates within the WKT to match the GeoJSON convention of [longitude, latitude]. The output GeoJSON will also include the WGS84 CRS (Coordinate Reference System) as “EPSG:4326”.

Example:

policy "example"
permit
where
     var geofence = {
         "id": 789,
         "name": "Test Geofence",
         "calendarId": 1,
         "description": "A test geofence",
         "area": "POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))",
         "attributes": {
              "type": "polygon"
          }
       };
     traccar.traccarGeofenceToGeoJson(geofence) == '{"type":"Polygon","coordinates":[[[10.0,30.0],[40.0,40.0],[40.0,20.0],[20.0,10.0],[10.0,30.0]]],"crs":{"type":"name","properties":{"name":"EPSG:4326"}}}';

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