property stores a location value returned by a GPS unit that includes
the latitude, longitude, dilution, and number of satellites. The
location property value can be invalid if the parameters of the
property definition are not met. The transaction property location
type includes attributes to define these parameters for the location
value. The location property may also be set via rule functions
that take the latitude and longitude values, converting them to
a location value.
defining this property type there are certain attributes specific
to it for transactions and fetches verses objects. The object location
property will contain attributes to initialize the value with a
latitude, longitude, position dilution, and satellite count.
a transaction or fetch location property, these same attributes
can be set. In addition to these, there are also attributes to specify
what is considered the minimum requirements for a valid location
value for that property. These attributes set the minimum number
of satellites, and the maximo age and position dilution for a location
value returned from the GPS unit. If these minimums are not met,
the behavior is definable within the property. The value can still
be accepted, or it can be rejected.
For transaction and fetch
location properties, there also exist the common initialization
attributes. These attributes will override the defined latitude,
longitude, position dilution, and number of satellites values for the
Location Property Attributes
Transaction and Fetch Attributes
- Name: Contains
the internal unique name for the property definition. This value
must be unique among all properties within the same parent definition.
- Maximum Reading Age: This attribute specifies the maximum
reading age in seconds for the value returned by the GPS unit. This
reading age represents the last time the unit took a reading. The
Maximum Reading Age will dictate the oldest allowable reading for
the location property. A location with a reading age older than
the one specified in this attribute will be considered an invalid
- Minimum Number of Satellites: This attribute specifies
the minimum number of satellites used to calculate the location.
There is a minimum of 3 satellites required for any GPS location.
A higher minimum may be specified. Note that this differs from the
number of satellites the unit can see. This value specifies the
number actually used to calculate the location. If this number is
less than the minimum number specified the location will be considered
- Maximum Position Dilution: This attribute specifies the
maximum acceptable position dilution for a location returned to
the location property. This is an integral number with a range of
values from 1 through 50, inclusive. If the position dilution returned
with the location value exceeds this maximum the location will be
- Accept Invalid Data: This attribute specifies whether
or not a location value that does not meet the criteria set for
a valid location value to be accepted. If this attribute is set,
invalid locations will be accepted. The property will return an
invalid location value, which may be checked using the rule function
The standard fetch and transaction attributes for initializing the property
and targeting object properties are available for the Location property
type. The attribute Initial Value includes the normal available
settings plus the options listed below, which are specific to the Location
- Current Location After Data Entry: This option
specifies the property should be updated to the device’s location
after the transaction has been finished and just before it is applied.
This value is obtained from the device’s GPS unit.
- Current Location Before Data Entry: This option specifies
the property should be updated to the device’s location before the
transaction is displayed to the user. This value is obtained from the
device’s GPS unit.