@ManuelB I fully acknowledge and accept your business requirements and use case.

Here is a similar one for you. I have students on Campus who want to see who from their coffee-club or study-group is on Campus. If there waiting for someone they want to receive a notification when the arrive. GeoLocation.watchPosition must be empowered to re-instantiate a SW that has been terminated.

The SW will interrogate the location change event before XHRing the information to a central server. It is the server that decides which GeoFences have been traveresed and, if so, which users need to receive a Notification.

Privacy and Security is handled as usual by the manifest triggering user approval at installation time. The individual Web App with also ask for tracking-permission when the user accepts individual group membership.

Please also see my comments in this thread: -
https://github.com/w3c/geofencing-api/issues/25

@marcoscaceres I think you are being too end-user/device centric. I'll wager 3 sheep-stations and an oil-rig that Manuel's harvester drivers don't look at the phone from one field to the next yet the Farmer wants to be able to load the page at anytime and see a real-time feed of where his harvesters are and if one is heading home while Fred still has half a field to head then he'll ring him up and let him know.

How about a trucking company wants a central head office PC constantly tracking truck movements in real-time.

Dominos Pizza want to let users see where their pizza van is. The van driver doesn't have to have his phone screen on killing his battery for Pete's sake.

SW developers are simply being obtuse if you continue to deny the requirements for location tracking and not just a hamstrung, debilitated geoFence API.

User's want to know more than "Elvis has left the building"!

@ManuelB Please be aware that, according to Mark (in the following Chrome bug report) Firefox, the Android Browser, Opera, and Safari already implement something akin to the CPU lock that Marco discusses: -
https://code.google.com/p/chromium/issues/detail?id=506435

I haven't tested Mark's claims which seem to be a complete alternative to Service Workers but FYI.

I found this a useful layman's reference for hardware support of geofencing: -
http://gpsworld.com/putting-the-ultra-low-power-in-geofence/

Explains a lot to me especially about power consumption,

I maintain that the SW architecture, in combination with any Android support for position batching, that subsequently offloads geo-fence processing to a central server in order to determine alarm/other processing for ALL users, is a viable if not preferable alternative.

Whether or not a wake-lock or cpu-lock is a retrograde step in power consumption, its implementation and availability pays homage to the user's right to self-determination. Likewise the user should be empowered to authorize GPS tracking while the phone is off.

Surely a myopic cluster of GNSS ICs is a less than optimal solution for fleet management or social networking, and an instance of functionality-devolution gone too far? IMHO, other than for monitoring prisoners on probation, the current geofence solution is a textbook case of the tail wagging the dog.

A Service Worker should be able to subscribe to a PositionManager optionally specifying min distance and/or seconds between updates to the position. A positionChanged event will be sufficient to re-instantiate a terminated SW.

Below is how I throttle GeoLocation.watchPosition now: -

Tier3Toolbox.prototype.LocationThrottle = 

    function(initHndlr, moveHndlr, standHndlr, errorHndlr, userOptions)
    {
        if(!navigator.geolocation) {
            throw new Error("Unsupported browser - No Geolocation support");
        }

        if (arguments.length < 4) {
            throw new Error("Insufficient call arguments");
        }

        if (typeof initHndlr  != "function" ||
            typeof moveHndlr  != "function" || 
            typeof standHndlr != "function" ||
            typeof errorHndlr != "function") {
            throw new Error("The Init, Move, Stand, and Error handler parameters must be functions");
        }

        var lastPos, trackerId, loiterTimer, deltaMetres,
            recalibrateTimer, lastOptions, lastDrop, replayTimer
            ;

        var MAXSILENCE    = 30;
        var watchCount    = 1;
        var acceptCount   = 1;
        var lastUpdate    = 0;

        var initHndlr     = initHndlr;
        var moveHndlr     = moveHndlr;
        var standHndlr    = standHndlr;
        var errorHndlr    = errorHndlr;

        var options, defMaxSilence, timeDetent, spaceDetent,
            loiterDetent, maxLocAge, accurate, maxSilence, lastOptions
            ;

        function moveReplay()
        {
            replayTimer = null;

            if ((lastDrop.timestamp > lastPos.timestamp)) {
                lastDrop.timestamp = Date.now();
                filterLocation(lastDrop);
            }                       
        }

        function loiterLimit()
        {
            loiterTimer = null;
            standHndlr.call(null);
        }

        var recalibrate = 
            function()
            {
                if (window.console) console.log("recalibrating");

                recalibrateTimer = null;

                if (trackerId) navigator.geolocation.clearWatch(trackerId);

                getCurrent(initAcc);
            }

        var getCurrent = 
            function(success) 
            {
                navigator.geolocation.getCurrentPosition(success,locError,{
                            enableHighAccuracy: false,
                            maximumAge: Number.POSITIVE_INFINITY,
                            timeout: 10000
                        });                             
            }

        var initLoc = 
            function(position) 
            {
                lastPos = position;     
                initHndlr.call(null, position); 
            }

        var initAcc = 
            function(position) 
            {
                watchCount++;

                trackerId = navigator.geolocation.watchPosition(filterLocation, locError, {
                            enableHighAccuracy: accurate,
                            maximumAge: maxLocAge
                        });

                recalibrateTimer = setTimeout(recalibrate, maxSilence);                 
            }

        var start =
            function(userOptions)
            {
                parseOptions(userOptions);

                trackerId = navigator.geolocation.watchPosition(filterLocation, locError, {
                            enableHighAccuracy: accurate,
                            maximumAge: maxLocAge,
                            timeout: Number.POSITIVE_INFINITY
                        });

                loiterTimer = setTimeout(loiterLimit, loiterDetent);
                recalibrateTimer = setTimeout(recalibrate, maxSilence);
            }

        var parseOptions =
            function(userOptions)
            {
                options       = userOptions || lastOptions; 

                defMaxSilence = (("maxSilence"  in options) ? options.maxSilence        : MAXSILENCE    );
                timeDetent    = (("minSilence"  in options) ? options.minSilence        :             0 ) * 1000;
                spaceDetent   = (("minProgress" in options) ? options.minProgress       :             0 );
                loiterDetent  = (("maxSnail"    in options) ? options.maxSnail          : defMaxSilence ) * 1000;
                maxLocAge     = (("maxAge"      in options) ? options.maxAge            :             0 );
                if (maxLocAge != Number.POSITIVE_INFINITY) maxLocAge *= 1000;
                accurate      = (("accurate"    in options) ? options.accurate          : true          );
                maxSilence    = defMaxSilence * 1000;

                lastOptions   = options;
            }

        var locError = 
            function(error) 
            {
                errorHndlr.call(null, error);
            }

        var filterLocation = 
            function(position) 
            {
                if (!lastPos) return;

                watchCount++;

                if (position.timestamp <= lastPos.timestamp)
                    return;

                var currTime = Date.now();                  
                var dropping = false;

                if (((position.timestamp - lastPos.timestamp) < timeDetent) ||
                    ((currTime           - lastUpdate       ) < timeDetent)) {
                    dropping = true;
                } else {                            
                    clearTimeout(recalibrateTimer);
                    recalibrateTimer = setTimeout(recalibrate, maxSilence);
                }

                deltaMetres = Tier3Toolbox.calculateDistance(
                                position.coords.latitude,
                                position.coords.longitude,
                                lastPos.coords.latitude,
                                lastPos.coords.longitude)

                if (deltaMetres.toFixed() < spaceDetent) {
                    return;
                }

                if (dropping) {
                    lastDrop = position;
                    clearTimeout(replayTimer);
                    replayTimer = setTimeout(moveReplay, timeDetent);
                    return;
                }

                acceptCount++;
                lastPos = position;
                lastUpdate = currTime;

                clearTimeout(loiterTimer);
                loiterTimer = setTimeout(loiterLimit, loiterDetent);

                moveHndlr.call(null, position, deltaMetres);            
            }

        var stop = 
            function()
            {
                if (trackerId) navigator.geolocation.clearWatch(trackerId);

                clearTimeout(recalibrateTimer);
                clearTimeout(loiterTimer);
                clearTimeout(replayTimer);
            }

        parseOptions(userOptions);                                      
        getCurrent(initLoc);

        return {start : start, stop : stop};
    };

@martinthomson

I hate to make this a point of jurisdiction, but I think that this is a discussion that needs to be had in the geolocation working group.

I've been careful to avoid any demarcation issues by always involving the Service Worker AND GeoLocation communities. My lobbying has centered on: -

Forums:
https://github.com/slightlyoff/ServiceWorker/issues/745
https://github.com/w3c/geofencing-api/issues/25

Mailing Lists:
public-webapps@w3.org
public-geolocation@w3.org

If there are better forums then please let me know.

Having said that, I am becoming more and more convinced that this is a Service Worker issue. The following is what I believe is required to make this work: -

ServiceWorkerRegistration.travelManager (getSubscription(), permissionState(), subscribe())
The subscribe() method with take options such as (minMsecs/metersl between position updates, accuracy, etc)

A new ServiceWorker "Travel" event will be created. The UserAgent must be able to re-instantiate a previously terminated ServiceWorker on the strength of this event.

One GeoLocation watcher per UserAgent sounds battery-friendly to me!

I'm very nervous when someone saves their hands when it comes to the privacy story. The web has thus far had a great accountability story and adding the ability to track someone when they aren't visiting your site is one capability that could easily undermine all the good work we've done. I'd want to see a clear plan for how a user is able to remain in control to be even remotely comfortable that watchPosition could be exposed.

God gave us valium and SSRIs for just such occasions. Either way please don't FUD a technical forum with tales of "There be dragons".

Users are running a WebApp and NOT "visiting your site". Permissions are there for just such a requirement. BTW I tested Firefox last night and it is the only browser that DOES continue to track you when the browser is in the background.

But can I ask where have you articulated your fears about WAKE-LOCK and CPU-LOCK back-dooring user-tracking functionality? What about the new GeoFence API? If I throw a 5m GeoFence around my current location and get a "leave" event then surely I can just drop that geofence and recreate another around my new current location. What is that if not user-tracking?

Most importantly, can I stress that this is a user REQUIREMENT and not an IMPOSITION! Ask all the permission questions you want but this simply has to happen.

Look I %100 acknowledge the problem(s) @martinthomson highlights, and the need to prevent abuse from the black hats. All I’m saying is let’s work the problem rather than simply rocking in the foetal position, or worse, concocting artificial and exaggerated speed-humps on the release path of much needed functionality.

On the plus side: -

1. User permission must be explicitly granted before GPS is accessible.
2. While GPS is being watched, even in background, the circles/ripples icon cue is visible to user on the device.
3. The underlying Service Worker architecture mandates the use of secure/authenticated httpS communication.
4. The user can be 100% sure tracking is off by simply closing the browser on their device.

I personally think the above is enough, but for the sake of argument, does anyone have thoughts on how access may be further governed?

1. Only permit background/service-worker GPS access if the Web App is installed/home-screened?
2. If a single GPS permission will cover both background and foreground access, then put a link on the toast to the Faustian details?
3. Use a new icon, perhaps an eye or a doughnutted version of the current GPS ripples? Pulse the icon?

Similar conundrums so that Service Worker GPS is not singled out unfairly: -

1. Firefox currently continues to process watchPosition events in background
2. All browsers except IE and Chrome continue to watchPosition when phone is locked but browser tab in foreground.
3. The proposed WAKE-LOCK and CPU-LOCK will backdoor user-tracking
4. The proposed GeoFence API, as it stands, will be another backdoor to user tracking
5. Native Apps can do this with impunity
6. Push Messages must be required to trigger a notification so as not to be silent/stealthy.
7. Geofencing is still tracking! Knowing when my next victim leaves their house each Tuesday is still an intrusive invasion of one’s privacy if it has not been sanctioned. Surely the degree of “badness” is not the issue here?

Also, can I list just the proposed restrictions on the GeoFence API that I know about: -

1. Maximum number of geofences
2. Only circular geofences
3. Maximum area of a geofence
4. Minimum area of a geofence
5. (Soon to be?) Cannot create a geofence in a service worker.
6. Fat Client, heuristically-challenged, localized, geofence processing
7. A technology born of a time when Java was king and batteries were the size of a brick and lasted just 2 hours.

Are these design smells not beginning to make people think twice?

Finally, to address some of Martin’s comments directly: -

Tracking the user in the background is highly likely to be a case of a site acting poorly.

Unsubstantiated, conjecture, hearsay, prejudice, and FUD :-(

A plethora of valid business cases and user-requirements have been portrayed for all who are willing to see. We must find a way to satisfy these legitimate requirements whilst fire-walling against malicious intent.

I want to ensure that the user remains in control;

Here we are in violent agreement! See the “plus side” above. How more empowered can the user be?

Look, I enforce my right to privacy more than most, I can assure you! I am not on FacePlant, LinkedIn, etc. I do not use my real photo on the net. I pay cash everywhere I can, and wish I could stop my card having Tap-n-Go. But @mulderandscully I do not wear a tin-foil hat.

I don't believe that asking users for permission is sufficient to that end for some types of features. This is one of them.

Can you please give me example of one or two other features that you felt failed your test? How did you get on overturning the SpeechRecognition API and access to that microphone?

The Service Worker developers must love all their children equally! Just because the blue-eyed boy of GeoFencing turned out to be the milkman’s mongrel doesn’t mean that your GeoLocation Cinderella can’t go to the ball.

Let’s get on with it – please.

@joemarini

Scenario: SW receives a push event, and my handler wants to check the current geolocation so I can warn the user about a potential nasty weather issue in their area.

Exactly Joe! But can I ask why you have devolved the "am I in danger" geofence logic to the client? Why send them a message if you know (or should know) that it does not concern them?

Weather is transitory and localized. If you follow my and @mkruisselbrink 's recommendations then the server will know exactly who is in/out of the danger zone and therefore needs to be PUSHed.

Please allow me to offer alternative requirements:-

1. University security have just been told there's a shooter on campus. They touch the google maps screen and tell the system to warn everyone in a 2km radius to get out or get down. The geoFence has only just been created. Pushing the details to the client won't help you because Martin et al have ruled out creating geofences in the Service Worker and we don't know if we're in the foreground on the device.

2. The library is closing. The librarian sends a push message to anyone in the building (who hopefully have their notifications on vibrate :-)

3. The next 10 customers to the Guild Tavern get a free beer. No use having permanent geofences around every retail establishment that may want to communicate with customers.

This is SERVER driven logic not fat client bloatware.

What's Mozilla doing? Floundering :-( Please see:
https://bugzilla.mozilla.org/show_bug.cgi?id=1216148
https://bugzilla.mozilla.org/show_bug.cgi?id=784505

Please put your WAKE_LOCK sledge-hammers away - all of you!

BTW. An additional piece of ServiceWorker GeoLocation governance, on Chrome at least, is that the gcm_sender_id/procet_id can be revoke for sites behaving badly.

Solution Addendum (Sorry)

Other Options: -
4) When the device goes to sleep when a Web App is still watching GPS, or simply backgrounds or minimizes a device-tracker, it should make a sound and or vibrate as a non-visual cue that tracking is ongoing?
5) When a device is reawakened or a device-tracking app is brought back to the foreground, then a notification must be sent to the user "This App continued to monitor your location in the background". The "Settings" icon on the message could facilitate "Prevent this app from tracking in the background" Forever/Just once.
6) Like the Push API the default must be DO NOT track in the background. If the user chooses the individual APP settings then they can turn it on?

GPS Tracking Use Cases: -

• Can I beseech the browser-developer community at large to please contribute their own use cases to this thread?

1. University security have just been told there's a shooter on campus. They touch the google maps screen and tell the system to warn everyone in a 2km radius to get out or get down. The geoFence has only just been created. Pushing the details to the client won't help you because the architects are currently considering banning creating a geofence around current position as it facilitates quasi-tracking. What's more is the time, bandwidth, CPU, and baterry-power wasted pushing a geofence to ALL users when most of them are not effected by or resident in the danger zone.

2. I want to track my jogging and bike-riding journeys to share with friends and manage calories-burned and effort. "Health & Fitness" market? Ignore it?

3. I want to know when members of my coffee club are getting close so I can start ordering.

4. Let me know if bad weather is moving in.

5. The library is closing. The librarian sends a push message to anyone in the building (who hopefully have their notifications on vibrate :-) giving clients 15mins to finish up.

6. The next 10 customers to the Guild Tavern get a free beer. No use having permanent geofences around every retail establishment that may want to communicate with customers.

7. How about a trucking or taxi company wants a central head office PC constantly tracking fleet movements in real-time.

8. Pizza Co. want to let users see where their pizza van is. The van driver doesn't have to have his phone screen on killing his battery for Pete's sake.

Look, I'm not paranoid enough to suggest that W3C members are on the take from the Native App providers but, Service Worker developers are simply being obtuse if they continue to deny the requirements for location tracking and not just a hamstrung, debilitated geoFence API. The requestWakeLock() method has it's uses for those who don't care about battery life. User/device tracking Apps is not one of them.

The devolved decision-making paradigm inherent in the current GeoFencing model is simply incapable of satisfying the legitimate business and user requirements.

I found a very interesting, and inspiring quote today that I'd like to share with you: -

https://twitter.com/jaffathecake
Googler. "I want the web to do everything native can, and fast."

So can anyone here explain to me how that precludes device/user tracking? Or how HTML5 Web Apps can not be available today with the same functionality as Uber, Domino's, GrindR, FaceBook, tomtom?

What the hell are you waiting for?

Here's a couple more platitudes to get you through to the next F2F plenary junket: -

https://twitter.com/jaffathecake/status/633621917547778048

"The web should look to increase its advantages while reducing its disadvantages. Native is doing this too. If the web stops, it dies."

"The web doesn't need to be better than native at everything, it just needs to be close enough that the gap in certain areas doesn't matter."

A victory for common sense. Excellent news!

On Thu, May 12, 2016 at 2:40 AM, Marijn Kruisselbrink mek@chromium.org wrote:
For quite a while now the geofencing API hasn't been much of a priority for us. Now in addition to that we're no longer convinced the geofencing API in its current shape is the best way to address the use cases we're interested in addressing. So with that in mind we've decided to stop work on the geofencing API in its current form.

Marijn

Combine that outcome with this at the upcoming TPAC: -

Hello All,

The registration for TPAC 2016 is now open - relevant information is provided in the email attachment below. There will not be a stand-alone meeting for the Geolocation Working Group, but there will likely be a joint meeting between the Geo WG and the Devices and Sensors (DAS) WG. This should be confirmed soon, and will take place during the DAS WG's allocated meeting time (Sep. 19-20).

Thanks,

-Giri Mandyam, Geolocation Working Group Chair

An the scene is set for a ServiceWorker.TravelManager.subscribe() outcome or, more likely, a generic sensor.AddListener(filterOptions). Either way these are exciting times indeed. Good Luck!

@RikdeBoer You might also want to watch https://bugzilla.mozilla.org/show_bug.cgi?id=1254911

Yes Blind Freddy can see the requirements and the merit in our arguments. What he can't do is make their Royal Highnesses of the IETF/W3C Cognoscente engage with the unworthy in providing a solution.

To date no one has found fault with my navigator.serviceWorker.travelManager.subcribe(options) idea with the capability of Throttle options to proxy the "interesting" movement test to the UA/Google Play/Message Console yet here we still are :-(

Nothing will happen before the Lisbon jolly.

@marcoscaceres - Settle Petal! It was certainly not my objective to upset the sensibilities of the artisans at International Rescue.

It's just that, on this outside of the Ivory Tower, the Employer/Employee relationship is normally one where the Employer pays the Employee money in return for directed work undertaken. Unlike @mkruisselbrink 's GeoFence waste of precious time and resources, the aforementioned work effort usually results in deliverables with agreed upon metrics with which to judge their fitness for purpose. Yep, I have to admit to being a tad envious of the "Just be wonderful, Darling!" duty statement.

Anyway, just because I, and Nigel Farage, may believe that most of those in bloated bureaucracies "have never had a proper job" is no excuse for trying to hold you to account and peel back the scab on the IETF/W3C circus. My apologies.

It's not that we've not found fault.

I'm happy to defend the design, or not. If you've got something better let's go with that!

BTW. was that the Royal "we" or are you speaking for someone else again?

make it impossible to have any sort of meaningful conversation about this topic with you.

Less talking; more doing. It's simply not that hard!

I honestly can't believe such a Prima Donna attitude actually exists and is allowed to fester in Australia. "I can't work with him Kyle! KYLE - I just can't work with him!" Really?

you have continuously shown yourself incapable of having a civil conversation

Bollocks!

I suggest to you that a full and frank exchange of views only appears uncivil when viewed through a passive-aggressive prism.

(why I had you banned from the W3C mailing lists already).
I'd again ask that you please remove yourself from the discussion

• or I'll ask Github to ban you from here also.

I have to admit that I've never met a lefty ideologue who wasn't vehemently opposed to free speech, but I am extremely surprised that Mozilla nurtures a culture of bullying. But allow me to counter your attempts at censorship with a request for you to resign from Mozilla or at least from the IETF/W3C standards junket. Time to hand the baton on and give someone less jaded a go eh?

It's not about me and its certainly not about you. Please let it be about "solutions" - not personalities! I left the schoolyard long ago.

BTW. Why didn't you or anyone else here deem @RikdeBoer worthy of a response? Yarpies are inherently uncivil perhaps?

Background GeoLocation - Just do it!

@LJWatson I am more than happy to disappear permanently from this mutual admiration society back to whence I came! I do not get paid for my time, so often wasted, here and while it can be fun, I don't get my jollies out of this sort of stuff.

All I want is progress on the two (and only 2) issues I've been banging on about for the last 6 months: -

1. Background GeoLocation. The world needs this yesterday!
2. Client-driven, Push-Manager mapped, Application Server unburdened, broadcast notifications

This repo deals directly with (1). The issues are well-known. ServiceWorkers are the implementation paradigm. The details can be bashed out in a couple of weeks’ Google Groups interaction and then the spec-writers can get to work.

Why is nothing happening???

• The key word "MUST" is to be interpreted as described in [RFC2119].

. You MUST engage with the industry user-base and software-vendors in the formulation of requirements before proposing standards.

. You MUST be agile in allowing for continual and iterative review and progressive input to specifications.

. You MUST publish design direction as soon as available so incorrect assumptions can be discovered.

. You MUST not deliver a fete accompli accepting no more than grammatical corrections.

. You MUST not seek to own a specification nor personal aggrandisement. It's about results!

. Your specification delivery times MUST be quartered.

. You MUST accept the umpire’s decision on abject failures such as https://github.com/w3c/geofencing-api and not subvert the decision like some deluded sook who voted for Brexit: STAY

. You MUST not attempt to fool all the people that navigator.requestWakeLock(“screen”) is the solution to the Background GeoLocation conundrum!

Leonie, it's just that I am not used to having work farmed out to autonomous-collectives that are seemingly accountable to no one but themselves, and get to cherry-pick assignments as the mood arises. Without any recourse options available, my frustration levels have to peak :-(

There are good people working on this spec

Can you please be more specific? The “ServiceWorker” spec? The “Background GeoLocation” spec? I know you’ve got heaps of good people available. Can we please get some on Background GeoLocation?

and it is the responsibility of the WPWG co-chairs to make sure that our part of the community is able to collaborate and converse positively.

Don’t bother to veil that threat Leonie. Imelda has already gotten me blackballed by stalking me around the Internet, silencing a dissenting voice, and interfering with my ability to eke out a living in the industry. I guess the W3C/Mozilla tentacles get everywhere :-( Why don’t you just turf me out of my wheelchair and kick me in the guts while you’re at it? “Let’s see how far you get in the standards industry now smart-arse.” At least you were “polite”.

So rather than indulge, empathize with, or even pity my Tourette-esque mental health issues you choose to hack me down instead. Truly some of the ugliest people I‘ve come across in a long time :-(

@RikdeBoer Really appreciate the empathy, and especially the kind words! Having said that, you’re backing the wrong horse mate. In truth, I am a bit of an obnoxious wanker really, always have been :-) I’ve got this knack of knowing what winds people up; it’s a gift. For example, take a quick squiz at Jake’s twitter feed. I knew I’d get him bristling with “lefty ideologue” and then once I quoted Nigel Farage it was all he could do to not stomp on his phone.

As far as “Yarpie” goes please don’t take it personally as I use it interchangeably with Saffa. No Afrikaans or dim-witted farm boy connotations. Let’s face it the Rik de Boers of this world were only ever going to come from so many places. But what are you doing in sun-deprived Melbourne? You can’t swing a cat in Perth without hitting one of your compatriots. I grew up in East Coburg and I can assure you that you got the short stick my friend. (Lucky the World Cup is so far away. If you can’t beat us now you’ll never beat us!)

This would be a shame.

Mate, it’s breaking my heart. I just can’t understand the delay let alone the recalcitrance.

BTW. I’m right into maps as well. Are you using the Google Maps API? KML as well? If you’re ever in Perth please let me know and we can catch up for a beer.

@chaals really appreciate the opportunity! Will try hard not to let you (and others) down.

@pietie

Can you please briefly explain your business/GPS requirements?

@chaals

There's the Wake Lock API proposal.

A very good proposal! This is needed over and above Background Geolocation. One is a screwdriver and the other is a spanner.

If I want navigation in my car, or I want to watch a cycle, car, or yacht race then I want the screen-lock. (I personally have no use for a CPU lock but others clearly do. Console/Monitor perhaps?) This functionality stops the user from regularly swiping the screen to keep it alive and allows the user to go hands-free and watch a movie, race, or map at more than arms-length. Excellent and essential stuff, but ridiculously hungry on battery power.

Background GeoLocation OTOH, allows the Web App to be backgrounded or the phone to go to sleep and be put into the Dominos delivery guy’s pocket, and yet interesting[1] location updates are still delivered to an existing Service Worker or a new Service Worker is instantiated for appropriate action. This paradigm plays well with SW re-usability, as a single SW can often survive and service an entire journey yet none will be consuming resources while the user is at rest. The SW is free to XHR/Fetch the location update to the fleet management server so that the end-customer can see exactly where their pizza is or you can watch Larry Ellison’s progress around Bermuda. NB: That the spec does not mandate that an a full-blow UA be instantiated by an implementation during this time, just whatever minimalist run-time environment and eco-system is required to keep an SW viable.

For any given GeoFence, a server may decide to Push a notification to the Web App telling it to foreground itself or at least tell delivery-guy that attention is required. Location updates can also be queued up by the SW as postMessage() calls so that when the Web App is foregrounded again it can drain the pipe/queue. (I’d like a way to collapse SW post messages to the client just like Push Messages can be collapsed by Firebase. Maybe it’s there already?)

Look I have plenty of detail to go around these bones but you get the idea right? Extremely battery and memory friendly yet full-featured essential Web App functionality.

Now on to your suggestion: -

A quick look suggests that adding "locationTracking" to the specified wake lock types wouldn't
be all that hard,

Actually, I reckon it’s nigh impossible. Hardware implementations, that I don’t understand aside, that sort of resource-allocation granularity just doesn’t exist or make sense (at least to me :-) How can the CPU be asleep for the Web App yet Javascript be freely available to service the location update? So I suggest that you are opting for a CPU/SYSTEM lock. The screen will sleep but all timer Events and any/all none screen emanating events will continue to fire and the CPU will be run down.

There may well come a time where mobile battery lifetime is not an issue, just like disk seek time is not an issue any more, but not in my lifetime.

and it would deal with the issue @RichardMaher raised of not needing e.g. the
screen to stay on.

Can you see the sophistication and superiority of my proposal? Much better to capture your troika/bike rides for posterity. WakeLocks are great! We need them! Just not for “Background” GeoLocation.

There is a privacy issue of course, and implementing this in a way that gives
users meaningful control is non-trivial.

Agreed. Many options available. Good experienced spec writers needed.

[1] “Interesting” location updates are those that meet the filter criteria specified as options when the serviceWorkerRegistration.TravelManager.subscribe({options . . .}) call. This acts as a throttle against a burst of location updates.

Ø MinJourney. Meters that must be travelled before reporting the location change.

Ø MinTime. Millisecs that must elapsed before reporting a location change.

Ø MaxSilence. Doubles as a sanity check that everything is still working and an opportunity to report a change previously delayed by MinTime. (Position.timestamp must reflect the original value)

Ø Accurate. Use accurate power-expensive feeds where available.

Ø MaxAge: Maximum number of millisecs between now and Position.timestamp before reading is considered stale.

Happy to work through the privacy issues here if someone is up for it?

Addendum: -

Another really useful resource/battery friendly aspect of the above design is that regardless of how many geolocation-using web-apps are "active" on the phone (while it's in a pocket etc) there is only one daemon (be it a UA or Google Play) that is consuming the listen overhead and deciding what's interesting.

Also, had a look at postMessage() and its event and can't see any collapse potential. I'm also guessing the only pipe or queue for messages is the Client's event queue. So would it be ok to listen for a Focus() event on the App window or document and discern that all postMessage events would have been received before the focus event? Or if a focus event is first then it can setTimer(0,allGeoUpdatesReceived) ? Then it can just action the very last one received.

In case your thinking that there is a lot of investigation and spec work required here you'd be wrong. Thanks to the foresight of the Service Worker spec writers and the thoroughness of the requirements gatherers, Background GeoLocation can take advantage of SW's inherent plug-n-play extensibility

Just copy & paste what was done with Notifications and we're there!

Can someone honestly tell me why the Web is not providing this???

I am happy to address any concerns or perceived problems. IMHO the only work left is: -

• Decide on appropriate permissions protocol for acceptance and tracking discovery/visibility.
• Decide whether you call it a TravelManager or a LocationManager or a.n.other
• Decide whether the TravelEvent parameter is just the position object or is overloaded

What else is there?

Web Apps can now compete directly on a much more even playing field with Native Apps. Is that not the goal? Let's cheer from the roof tops?

@dandv @RikdeBoer @mvano @antogh @jms19

Please also see w3c/permissions#112 (comment) for a discussion on Permissions API involvement.

@marcoscaceres I made an undertaking to @chaals that I would keep my involvement here professional succinct and objective. I intend to do just that but I honestly believe it would be much easier if you could recuse yourself from further involvement in anything to do with Background Geolocation. This has absolutely nothing to do with your abilities, just acknowledgement of the fact that we have a personality clash that could impeded progress. The fault lies with me not you.

I'm sure W3C have many capable people lining up. Perhaps from Edge?

I can't, sorry. It's literally my job to be involved in these discussions.

Then I only ask that you spend the same time and have the same amount of input to Background Geolocation as you've had to Background Sync and Background fetch. I also recommend that your boss considers Business Continuity or Disaster Recovery or simply let you have a holiday.

it still won't happen for at least 3-5 years.

My contention is that any reasonably talented group of spec writers and/or developers could deliver the desired results in 6 months without violating any of the laws of physics. Where there is a will there is a way!

I also feel it is time for the Waterfall method of spec-writing to be challenged with something more Agile or RAD. I think the lack of competition in the standards space may ultimately be counter-productive. I forget who first asked but I am reminded of "Why is there only one Monopolies and Mergers Commission?"

I see merit in that strategy. Maybe this is a great opportunity for Firefox to finally secure a mobile presence by being the only browser to ship Background Geolocation, and do it in conjunction with specification development?

Shadow DOM also seems to have been developed that way with v1.0 and SLOT input from Apple.

But, once again, Background Geolocation is not a departure from the norm or a seminal moment in Web evolution. It is just using the tools and infrastructure already in place thanks to the specification giants that have gone before us. Service Worker Extensibility is there! Permissions are (almost) there! All that's left to argue about is nomenclature.

We need the UA or other omnipresent daemon (which currently exists to support push notifications) to watch location changes and deliver TravelEvents to and existing SW or instantiate a fresh one. Sorry but I just don't see 3 years work in that!

Ok, forgetting green-field implementation aspirations and fully embracing "we are where we are" pragmatism, the following is a very workable Background GeoLocation permissions solution: -

The PositionsOptions Interface needs to be expanded to take:

• boolean enableBackgroundWatch = false The UA will know to expect/accept a registration request with the TravelManager but, if not, who cares? ServiceWorker instantiation and TravelEvent delivery will only occur when the Client page/app is backgrounded or the phone is asleep i.e. It is the UA's responsibility decide when the mainline/client is incapable of receiving location events. For permissions, If not perviously granted, user-permission must be sought clearly specifying "Background Location continuity" in the permission description. [This attribute will be ignored (thrown?) for getCurrentLocation] TODO: Although Location has a sub-permission of "accurate" (at least on Android) and now "background", there appears to be no way to set the sub-privileges individually. How do other privileges handle this granularity? Tickboxes?
• unsigned long minJourney = 0 If omitted there is no minimum distance required an all events will be delivered. [This attribute will be ignored (thrown?) for getCurrentLocation]
• unsigned long minInterval = 0 If omitted no period of time must elapse between location events,[This attribute will be ignored (thrown?) for getCurrentLocation]

Cons: -

1. I'm guessing UA implementations of watchPosition() are done in the Tab/App/process context and not globally at the UA.
2. Messy having two registrations for the "same" event? TravelManager and watchLocation
3. The tight coupling of SW and Client could be undesirable and confusing. Especially for fleet management where sometimes the server is updated from the Client and sometimes from the SW. Perhaps a "boolean enableForeground = true"? If false SW will get all position events foreground and background?

Plan B

Separate "Background Location" permission required. Total isolation/mutual exclusion between Client location gathering and Service Worker's efforts: -

// https://example.com/serviceworker.js
this.ontravel = function(event) {
  console.log(event.position);
  // From here we can postMessage() the position details to client, 
  // we can foreground the client, or we can merely XHR/Fetch the details
  // to the fleet-management server so that everyone can see where their pizza is.
}

// https://example.com/webapp.js
navigator.serviceWorker.register('serviceworker.js').then(
  function(serviceWorkerRegistration) {
  // This next line is when the user gets prompted for background geolocation access permission
    serviceWorkerRegistration.travelManager.subscribe({accurate:true, minJourney:10}).then(
      function(pushSubscription) {
        console.log(pushSubscription.options);
      }, function(error) {
        // During development it often helps to log errors to the
        // console. In a production environment it might make sense to
        // also report information about errors back to the
        // application server.
        console.log(error);
      }
    );
  });

Cons: -

When Ultimate Web Apps are first-class citizens, how to incorporate/surface the ability to turn off just background-geolocation permission and not just the sledge-hammer of all Location?

They're designed to wake up for an event, briefly handle it, then go away. This should be especially brief if the user doesn't have a tab open to the site.

No they are not. This has been explained to you many times before by wonderfully talented people like Ben. Simply repeating a lie/conjecture over and over does not make it any the more true.

I hope the irony of you literally just typing this: -

You can't simply state these things, you need to give reasoning. By showing your working, it may become obvious that your understanding of these features is incorrect.

over here was not wasted on anyone.

The fact that the spec says a UA may terminate a SW at anytime by no means implies inevitability or compulsion to do so and, if the two quoted implementations are anything to go by, it simply doesn't happen. I'm not sure if you're FUDding intentionally or you simply don't understand the performance benefits of Service Worker recycling.

Even with the stipulated restrictions on global state, Service Worker re-use is extremely desirable for the performance of a subsequent Push Notification or Travel Events as well as the reduction in the device resources needed purely to spin-up/run-down a service worker. Why would one not leverage this low-hanging performance fruit? In fact, in the absence of memory and/or CPU resource load I can't see why Service Workers don't enjoy extended lifespans.

Anyway, "To reiterate my previous comments: " See how the ServiceWorker paradigm fits shimlessly with user movement: -

Travelling->Travelling->Travelling->------------At Rest---------> Travelling scenarios.
< ------- Service Worker 1 ------------>...................................................<-- SW 2 --->

Then, of course, there is the beauty of not having to foreground and/or instantiate a client/complete-UA if all the SW wants to do is tell fleet management (or facebook friends) that you've moved! This is a marriage made in heaven.

Yep, Service Workers and Background Geolocation truly are a Dream Team!

WRT other FUD on wake_lock sledge hammers: -

This shouldn't be any worse for battery,

It's possible that memory usage will be greater keeping a page open vs a service worker, but I'm not sure by how much.

Really? Not even anecdotal? Can't "simply state these things" . . . :-(

I'll let that sort of informed opinion and scientific analysis go through to the keeper if you don't mind. There's too much to be achieved and too much work to be done.

To clarify, I'm referring to the kind of geo tracking that an exercise tracker would need. Geofencing is a different thing, and does kinda fit with service worker's model.

"A different thing that kinda fits". Well I certainly can't argue with that.

FYI Chrome has abandoned the GeoFencing specification and there is no other intended implementation.