GPS Capturing Support

GPS locations can be captured in the foreground (i.e. the user can see that the location is being captured) or in the background using the gps component. To use the gps component, you need to define an attribute or variable with type location.

Example — "Foreground" Capturing

The following example shows how GPS location capturing can be performed in the "foreground" i.e. the user sees a map showing how their GPS location is captured.

View XML:

<?xml version="1.0" encoding="UTF-8"?>
<view title="GPS Test">
    <var name="current_location" type="location" />

    <gps bind="current_location" />
</view>

Example — "Background" Capturing

The following example shows how GPS location capturing can be performed in the "background" i.e. the user does not see an indication in the app that the location is being captured.

View XML:

<?xml version="1.0" encoding="UTF-8"?>
<view title="GPS Test">
    <var name="current_location" type="location" />

    <gps bind="current_location" show-if="false" />
</view>

Accessing GPS Information from JavaScript / Format Strings

These properties of a GPS location variable or attribute can be accessed from JavaScript and Format Strings, but cannot be modified:

latitude
longitude
altitude
horizontal_accuracy
vertical_accuracy
timestamp

Example — Accessing GPS Information from JavaScript

function update_coordinates() {
    if(view.current_location == null) {
        dialog("Location", "Unknown");
    } else {
        dialog("Location", "" + view.current_location.latitude + ", " + view.current_location.longitude);
    }
}

Example — Accessing GPS Information from Format Strings

<table>
    <info label="Latitude" bind="current_location.latitude" />
    <info label="Longitude" bind="current_location.longitude" />
    <info label="Horizontal Accuracy" bind="current_location.horizontal_accuracy" />
</table>