Oracle APEX Geolocation 1: How to get your location

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Some decades ago people used to work in an office. And occasionally they went on business trips. Nowadays users are much more mobile. They can work from home, form the office or from a field location. So their location varies and it can be useful information for the applications they use.The location might be tied to a customer or a fact that should be reported. This series of blogposts will deal with determining the location in Oracle APEX, and how to use and display it:

Part 1:Getting the location

Part 2: Using Oracle Spatial

Part 3: Display location(s) on map

Part 4: Correct locations on map

Part 5: Getting location data from photos

The parts without link are not yet available.

There is an example application available at :  https://github.com/dickdral/apex_location_demo

Getting your location in the browser

In order to retrieve your GPS location in the browser some JavaScript needs to be applied:

function getLocation() {

  if (navigator.geolocation) {

    navigator.geolocation.getCurrentPosition(function(position) {

        alert(`Latitude: ${position.coords.latitude} \n` +

              `Longitude: ${position.coords.longitude}`);

    });

  } else {

    alert("Geolocation is not supported by this browser.");

  }

}

The most important line is the call to navigator.geolocation.getCurrentPosition.

 This is the function to retrieve the GPS location. As this may take several seconds the function is asynchronous.  The function to be performed after retrieval of the location is the argument for the function. There also is a check when the function is not available.

After the call JavaScript will immediately continue with others tasks. Otherwise the page would hang until the function returns.

NB The function can only be called from a https web site.

Accuracy

In ideal situations the accuracy of the location is within a few meters. In less favorable situations this might expand to tens of even hundred of meters. Especially in an urban environment with many high buildings the visiblity of the GPS sattelites is less good and the accuracy is less accordingly.

More information on GPS accuracy can be found  here

Privacy

Privacy can be an issue when you retrieve and store the location of employees, customers etc. The privacy legislation differs per country.

As of May 2018 the General Data Protection Regulation is issued by the EU. This law contains high penalties for offenders. It is wise to take notice of the privacy regulations in the countries where the application will be used.

Getting location using a APEX plug-in

For APEX developers it is not necessary to write JavaScript to retrieve the GPS location. You can use the Store location plug-in that can be found on https://apex.world.

After importing the plug-in in your application, you can reference it in a dynamic action. All you need to fill in are the APEX items to store the latitude and longitude once the location is retrieved.

To define follow-up actions a custom DA can be defined acting on the event location-retreived.

Happy apexing ;-)