Serviceworker: Expose GeoLocation to workers

[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.

[mvano]

How do you think the privacy and security aspects of this should be handled? It's not trivial to permit precise background location tracking.

[joemarini]

Agreed - filed this at AlexR's request, they will work these out in spec.

[mkruisselbrink]

It doesn't sound like you need the actual current geolocation for that usecase? You just want to know if the user is in a specific area, so adding a geofence should be enough for that, at least as it is currently specced. That still has the privacy and security aspects of course. We haven't quite worked out yet what should and shouldn't be allowed with respect to registering geofences from a service worker while there are no clients currently shown.
Also maybe the list of potential areas is too big to actually register geofences for all of them, so I agree that having a way to get the current position from a service worker could indeed be valuable. I'm not convinced that having a way to watch the current position is something that we want to expose to service workers though. Certainly not if that would mean constantly waking up/keeping up the service worker while somebodies device is moving... There are of course usecases for background location tracking, but I think some kind of API where chrome does the tracking and only passes on a complete track would be a much better API for service workers.

[joemarini]

The use case that the travel partner gave me was "user gets on a plane in Vancouver, checks weather. Puts phone away. Flies to Boston, gets weather alert for storm in Boston, not Vancouver." Also, if the user is driving across the country or state, it wouldn't be practical to pre-set a geofence for the whole way.

It seems like if this was properly badged in the UI and the user knew it was happening, it could be made more secure.

[mvano]

Where would one badge this in the UI? The API would run in a service worker in the background, so the badge would be the only UI surface. Especially on mobile, screen space is limited. A permanent indicator like a notification might be too much. A tiny icon in the status bar (that cannot be interacted with and has no text) might be too little.

A list of possible UI requirements might be:

• The user can understand what it means
• It is discoverable
• It is not too distracting from other activities
• Attribution: it indicates which origin is using the API
• Permission revocation: the user has a path from the indicator to revoke the permission
• Battery blame (how much was used by this API)
• Does this UI pattern scale to work with other APIs? What if there's a dozen of them?

I don't want to solve the UX in this thread, but I do want to point out that this is tricky. It might not be worth the trouble unless we find more common use cases.

[ManuelB]

Hi,
I am working in the agriculture business. During a crop season it is necessary for all the farmers taking part in a harvesting task to see each other on a map to be able to join somebody who isn't done yet with his field. Harvester and transporter are working closely together.

Further the traces are used afterwards to generate precise work logs to see where the harvester have been and how long it took to harvest a particular field. Traces are also used to make sure that chemicals are only used on the allowed field.

There are already multiple native solutions to solve these problem but it would be awesome if this can be solved using a native API.

So technically what I need is an API that I can tell that it should send reliable message with the position of the device to a given URL for a certain timeframe. If the device is offline it will collect the message and the next time it is online if will send all messages in the queue. The message should expire after a given time.

When the browser asks to do this tracking the user should be asked if he wants to allow the particular website to track his position for a certain period of time.

Hope that use case helps to enhance the APIs.

/Manuel

[mkruisselbrink]

The use case that the travel partner gave me was "user gets on a plane in Vancouver, checks weather. Puts phone away. Flies to Boston, gets weather alert for storm in Boston, not Vancouver." Also, if the user is driving across the country or state, it wouldn't be practical to pre-set a geofence for the whole way.

I do fully agree that "Get the current location" might be something we should let service workers do, but to solve that particular use case with geofencing you'd set a geofence for the current location, with some reasonable radius, which would then wake up the service worker when the user has moved that far away.

[mkruisselbrink]

I'm not quite planning to actively work on any of this (other than the geofencing API I'm working on), and the UI issues are definitely non-trivial to solve, but I started trying to write down some of my thoughts on what the space of use cases for "geolocation in service workers" looks like, and what kind of APIs might work to address which use cases. That (not very well thought out) attempt can be found here.

[jakearchibald]

The fitness tracking case (and I think @ManuelB's case) can be solved using standard pages, perhaps with the addition of some kind of "pinning" API that keeps the page alive.

This doesn't solve @joemarini's case though. @joemarini: why is the location check triggered by a push message?

[ManuelB]

@jakearchibald I agree the important point is that I need to run a background task. We already build prototypes using WebSockets and watchPosition that worked well but the problem is as soon as the browser is suspended, closed or somebody calls the action is interrupted.

[RichardMaher]

@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]

@ManuelB I think what you want is the Wake Lock API... but with some additions we are yet to add to the spec: you could set a "CPU lock", which would keep the page alive, but would allow the screen to sleep (and maybe generate notifications as needed). Alternatively, you could keep the screen lock on - and just let the app run.

[RichardMaher]

@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"!

[RichardMaher]

@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.

[ManuelB]

@marcoscaceres Thanks a lot I will look into it and report my findings.

[RichardMaher]

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. Thanks to @RichardMaher for bringing it to their (and my) attention.

This is a topic that has come up in the past and I think that I myself proposed that a single request for location was a fine thing. We did discuss the subject at some length.

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.

[RichardMaher]

@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:
[email protected]
[email protected]

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.

[mkruisselbrink]

@RichardMaher I totally agree with @martinthomson that none of this is really a service worker issue. All of what you describe is about features build on top of service workers, so the geolocation working group would most definitely be the correct location to actually pursue this.

Having said that, what you describe does sound very similar to parts of the API I sketched in https://github.com/slightlyoff/ServiceWorker/issues/745#issuecomment-149379448 (and https://gist.github.com/mkruisselbrink/d0d38b38979a37778e71, or in a version not specifically about geolocation in https://github.com/w3c/sensors/issues/73).

And yes, the new geofencing API has a lot of the same privacy and permission related problems as what you're describing. We haven't really figured out yet what to do about that (although a spec compliant implementation could not allow registering of new geofences from the background under certain circumstances, which would make adding a new geofence around the current location impossible).

[martinthomson]

I think that @RichardMaher forgets that sometimes browsers have to deal with sites that act poorly. Tracking the user in the background is highly likely to be a case of a site acting poorly. I want to ensure that the user remains in control; and I don't believe that asking users for permission is sufficient to that end for some types of features. This is one of them.

[RichardMaher]

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.

[RichardMaher]

@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.

[RichardMaher]

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.

[RichardMaher]

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?

[RichardMaher]

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.

[RichardMaher]

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."

[RichardMaher]

A victory for common sense. Excellent news!

On Thu, May 12, 2016 at 2:40 AM, Marijn Kruisselbrink [email protected] 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]

Agree very much with the use-case scenario's described by @ManuelB and @RichardMaher.

There are dozens of use-cases for being able to receive and record geo position updates, whereby the initiating (web)app may or may not run in the background, as the user is temporarily on another tab, or app, and/or has put their mobile device in (s)low-CPU/low-power mode.

With Progressive Web Apps touted as the new way to go and ServiceWorker being one of the mandatory components of PWA, ServiceWorker seems a natural fit.
If not ServiceWorker, then something else. Please redirect me if there is a better place where I should state my case.

But somewhere in PWA we need to be able to receive position (lat/lon) updates from the mobile device's hardware and pass these on to the page that originally activated it.
As I understand it, currently ServiceWorker does not have access to navigator.geolocation, let alone navigator.geolocation.watchPosition(), so in this respect PWA cannot offer what native apps can.

Sure, we must be prudent when it comes to power/battery requirements and privacy issues.
But when I can start a native app on my phone, fully warned & aware that it will use a lot of battery power and that it is recording position updates (because I want it too), then why, should we not have that same functionality under PWA?

As a lover of maps and entrepreneur in the market segment of geolocation-based mobile solutions, this feature, more than any other, is holding PWA back from being something truly great.

[RichardMaher]

@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]

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 :-(

It's not that we've not found fault. It's that your constant abuse of people engaged with the standardization process and insane conspiracy theories make it impossible to have any sort of meaningful conversation about this topic with you.

Despite good faith attempts to allow you to collaborate, you have continuously shown yourself incapable of having a civil conversation (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.

[RichardMaher]

@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!

[jakearchibald]

I would support a ban in this case. Not happy seeing friends and colleagues being insulted in this way. I'm on leave until next week, but I'll do it unless someone beats me to it.

[RikdeBoer]

Having come into this very late, and not knowing any past history, it looks to me that a great course may be hampered and possibly sunk by a war of words.

This would be a shame.

I do not know @RichardMaher or any history he may have with W3C or github.

For those of you who feel offended… based on what I read above, when I strip off the insulting or abusive language, I see an erudite man, who loves playing with words and is very passionate about pushing a feature request that makes common sense.

Geolocation is huge. Richard’s 8 use-cases above (Feb 19) are just the tip of the ice-berg.

Please do not be distracted or put off from working on the essential feature of "background geolocation” because of Richard’s tone.

PS:
@RichardMaher: calling me a “yarpie” based only on my surname is a long shot, even if meant as a double entendre ;-)

[LJWatson]

@RichardMaher
There are good people working on this spec (and others at W3C). You make some worthwhile points, but it isn't acceptable to insult and disparage people in the process.

This repo exists outside of W3C space at present, but the spec and the people working on it are part of the W3C community - 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.

Please abide by our code of ethics and professional conduct, and the advice given here.

[RichardMaher]

@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 :-(

[RichardMaher]

@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.

[slightlyoff]

Not an issue appropriate for this repo. Closing.

[antogh]

Sorry, i know this is an old thread but me too I'd like to ask to give us some way to build a web app that can use gps position even in background, for good purposes and with the user permission of course. There are tons of reasons for having this need, just consider the webAPP as an APP, not as web site. So today the only way to do this is with native app, examples of this kind of native apps are navigators, uber, glympse and I could go on with many others. A web app is perfectly capable to provide the same features with the same security for the user, but the browser is blocking this so we are forced to write native apps and to deal with multiple platforms and stores, creating friction for users that have to go through the long boring procedure for installing the app. We all know this way doesn't work anymore. Let's not stop the progress and let's make the web apps finally a reality. Thank you

[jms19]

I'd like to do a regular tracking (web) app for cycling so this is exactly what I'd like.

(Native Android though possible is a horribly over-complicated and non-portable way of doing this.)

[jakearchibald]

Pretty confident the service worker isn't the place for doing this. The best way is to give a page the ability to stay open, perhaps following a user permission, and shows a sticky notification so the user knows the site is still running. Then geolocation will work as expected. This feature would work for other long-running tasks too, and is closer to how browsers currently behave with media, and I believe it's pretty much how android does it.

[jms19]

I have since and after much hair pulling got a native Android tracker going though it might still be instructive to learn how effective (at not stopping) a web-based one would work. There is a similar issue with apps in whether the tracking bit should be attached to a window (or activity as they are known) or a service. In my case I want it to start and keep working no matter what. My experience so far is that there is some battery drain (maybe 10% over 4-5 hours) but then I'm asking the GPS to work every minute but that would be the same whether a proper app or a web-based one. Anyway it's nice to have my data stored on _my_ server and not Google's.

[pietie]

@jakearchibald is there an issue somewhere we can track that deals with this "keeping the page open" feature?

[chaals]

@pietie wrote:

@jakearchibald is there an issue somewhere we can track that deals with this "keeping the page open" feature?

There's the Wake Lock API proposal. A quick look suggests that adding "locationTracking" to the specified wake lock types wouldn't be all that hard, and it would deal with the issue @RichardMaher raised of not needing e.g. the screen to stay on. There is a privacy issue of course, and implementing this in a way that gives users meaningful control is non-trivial.

Since location information can come from several sources, some active and some passive, can use varying amounts of battery power, and are pretty seriously privacy sensitive, there would be some important details to get right in implementation as well as specifying what belongs in spec and what in implementation detail..

[RichardMaher]

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

[RichardMaher]

@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?

[RichardMaher]

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.

[RichardMaher]

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?

[RichardMaher]

@dandv @RikdeBoer @mvano @antogh @jms19

Please also see https://github.com/w3c/permissions/issues/112#issuecomment-305396356 for a discussion on Permissions API involvement.

[marcoscaceres]

We can keep the discussion here tho. I'm watching all the things 👀

[RichardMaher]

@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?

[marcoscaceres]

recuse yourself from further involvement in anything to do with Background Geolocation.

I can't, sorry. It's literally my job to be involved in these discussions. When my manager asks, "how did that get into the spec? are we seriously expected to implement that?!". I need to have an answer.

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

You seem to assume that we don't have a huge list of other priorities. Although this is important, it's not as important as other things. So even if we were all like, "yeah, we totally are going to do this!" it still won't happen for at least 3-5 years.

[RichardMaher]

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?"

[chaals]

@RichardMaher There are lots of reasons why someone - @marcoscaceres isn't unique, any more than you or I - would have other priorities. Each proposal has to stand on use cases and the people who are going to work on them. Which is not necessarily "fair", but is how reality occurs...

And to be clear, there are competing organisations writing specs for the Web, and the "waterfall" approach is increasingly being abandoned - the specs produced by WebPlatform and various other W3C groups are implementation led and test driven - which is one reason a good idea might not become "a standard" in just the time it takes to write the spec.

[marcoscaceres]

(Good example being web payments: where Google implemented like 1 year ago, Microsoft too is about to ship - Mozilla is helping write the spec and provide web platform tests, while implementing at same time for a release maybe sometime late next year)

[RichardMaher]

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!

[RichardMaher]

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?

[RichardMaher]

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?

[jakearchibald]

To reiterate my previous comments: Service workers aren't intended for continual background operation in the way that's being proposed here. 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.

Keeping a tab awake is a better solution as it isn't geo-location specific and enables a wider range of use-cases. It's also more privacy friendly as there's a tab the user can close to cease activity. On mobile, a sticky notification can inform the user about locked tabs/apps, and tapping the notification can return them to the tab. This is pretty much how Android does things natively.

This shouldn't be any worse for battery, unless your page is using more CPU than it needs to, eg doing work to update the page visually while it isn't visible. The page visibility API helps here, and CSS animations / requestAnimationFrame already stop when the tab isn't visible.

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. If this turns out to be an issue, we could look at ways to fix it (I'm not convinced it'd be using a service worker).

For any given GeoFence…

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.

[RichardMaher]

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.

[jakearchibald]

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'm one of the editors and designers of service workers (@wanderview is another designer), so I know a thing or two about what they were designed for 😄 . The link you provide doesn't 'disprove' what I'm saying. Browsers have a grace period to avoid additional startup costs, but service workers are terminated when they aren't needed.

over here was not wasted on anyone.

This doesn't appear to be related. The situation there is the same. Wake up for an event, terminate once complete.

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.

I am one of the people that designed what you call "service worker recycling". However, this does not mean workers can remain active for long periods of time when tabs are closed. Both Chrome and Firefox will terminate service workers when they're inactive.

Like I said in another thread, you should consider for a moment that you might not be the only non-idiot on the planet, and the source of your frustration may be your own lack of understanding. I empathise as I also engage in areas of development I'm less familiar with, but I increase my understanding by politely asking questions, and ensuring I test & understand conditions before declaring myself an authority – I've found this to be the quickest way to learn, and the best way to effect change.

I appreciate you made efforts to avoid being what I'd call an arsehole… briefly, but if you want to continue this conversation you're going to have to give it another go and stick with it.

I've abandoned responding to your post, but I'd happily continue if you apologise and restate your questions in a non-aggressive and polite manner. But do realise that I have no professional obligation to engage with you, so if you want to be heard (and it sounds like you're pretty eager to be), it's on those terms. Otherwise we'll have to wait for someone reasonable to discuss the features you're interested in.

[marcoscaceres]

@RichardMaher, it might be best we take this off GitHub. I'm happy to answer questions in real time about all the specs you keep hitting, but going around in circles and us all getting frustrated is not helping this move forward. We are in almost the same time zone- we can chat on slack, irc, hangouts... choice is yours. You know my email. Friday is free for me.

[RichardMaher]

Stackoverflow bounty closes in 40mins

[Zibri]

It would be great to send a push notification to (for example) a phone and get back a notification on the position. Also very good would an api for tracking a device. (As google maps can do). In this way everything (about geolocation) would be possible in a webapp too.

[Zibri]

About the security issues, IMHO it's simple: a new permission like GEOTRACK or something like that or INHERIT the permission already given to the origin and scope or the worker.

[MeritBased]

Can I please ask you all to consider looking outside the W3C/IETF opinion pool for solution and design ideas on this?

Stackoverflow for example: - Background Geolocation ServiceWorker - onMessage Event order when Web App regains focus has over 430 views and 12 votes and the answer a further 2 votes. Expected ratio of ServiceWorker instances to Geolocation Updates has 126 views plus 5 and 1 votes respectively.

The source-code for the TravelManager POC and polyfill, along with an aaa_readme.txt, can be found here

If you wish to see the example without copying then, after reading the readme file, run the Ultimate Web App from Brotkrumen

The CPU Wake Lock may well be all that is needed for other/true sensors but Background Geolocation needs the Service Worker Travel Manager!

[MauroJr]

Is there any plan to provide background geolocation for web apps, similarly as currently we can do background sync and push notifications?

My company would love to replace our current native app (Android / IOS) for a PWA, but unfortunately, it's not possible to do geofence in the background with a PWA.

For instance, our app does not require to be opened to alert the user for a geofence event, the geofence service starts automatically in the background.

Sorry if here it's not the right place to put this question, I can not imagine a background service running on a PWA other than through Service Worker. But I have no problem being wrong.

I just wanna see Web Apps to be capable to replace Native Apps in most possible scenarios and would love to know your opinions guys. Background Geofence is one of those scenarios which the PWA will not replace Native Apps?

[merlinnot]

I hope I’ll see the day when we’ll be able to take advantage of it. My company decided to go with PWA instead of native apps and it works great, but we currently have to maintain a “companion app” which does literally nothing but sends geolocation to the server. There’s even no UI except of signing in. User installs it once and never uses it again (in the foreground).

I’d be so happy to get rid of this weirdo ;)

[valeriob]

Since the issue is closed, is there an active discussion about this feature ?

[marcoscaceres]

No, but if you'd like to incubate an idea, you can propose it at https://discourse.wicg.io

[valeriob]

Thanks @marcoscaceres i posted it here https://discourse.wicg.io/t/proposal-expose-geolocation-to-service-workers/2588

[marcoscaceres]

Thanks, @valeriob! I'll just note that there is limited interest from browser vendors to take this on at the moment. However, there is no harm in developers exploring solutions. Will follow up on discourse.

[tomayac]

@marcoscaceres The discussion on Discourse starts to get, erm, noisy for similar reasons than it got noisy here. Nevertheless left some comments and hope they get noticed.

[merlinnot]

I don't use this phrase a lot in public posts, but... LOL. This discussion got waaaay out of hand, but everything is so easy in reality...

[karianpour]

I have a use case that getting a geo-location with distance/time based update is necessary, ofcourse with the user permission. So far, what I see, the only way is native app which the construction and maintenance is too expensive, so not feasible to do. But if it could be done in PWA, it would be feasible. The use case is in paragliding competitions where people fly in the air and the organizer MUST follow them for the pilot safety / air space security / competition rules. And also it would be nice to watch them live for spectators, as it is a more fun, just like watching football match. And after the competition, the organizer should collect all the 100 pilots scattered in a 60km wide field with designated vehicles.

I really appreciate the PWA spec so far and I make use of it in my web apps.

I think that people behind PWA are with web background trying to walk to the native app world. That won't make it good practice for a web app. I wish that there was some one with native app background one the community.

@jakearchibald , I understand your concerns. All the time you speak about PAGE, and so far what I found in "PWA" is "Progressive Web Pages" not App.

@marcoscaceres, I understand that you have to answer the people in the hierarchy, but being conservative will never make a change, and of course wiping away the question is the simplest. I wish that you boss some day asks you "Why did't you listen to the requests?"

Giving the geo-location by it self is not a privacy violation. And the use cases are a lot, and making it safe is hard.

The spec might be like to register to get the location every 3 seconds / every 10 meter, and the user get a permission box to allow or not. And the service worker get a location changed event every 3 seconds / every 10 meter.

[jakearchibald]

@karianpour

All the time you speak about PAGE, and so far what I found in "PWA" is "Progressive Web Pages" not App.

By page I mean the context that contains the UI, rather than a worker.

[adamburr100]

OK. I've come to this late and have read the whole discussion - phew!

My use case is one where mobile workers need to be tracked by their employer during their work shift to allow their location to appear on a "control map". This will improve the employees personal safety and also, if one employee is in distress it will be easy for the nearest other employee to be sent to give help.

Similarly, the controller can see which employee is nearest to a given location and can therefore despatch the closest employee to attend.

I am trying to do this using a PWA, but it currently fails to report the position whenever the browser is not being displayed.

Cutting to the chase, should I give up my PWA and write a native app, or is there a way to do this in a PWA?

I'd be grateful for any help with this decision.

[jakearchibald]

@adamburr100 the answer here is to keep the page awake, using something like https://w3c.github.io/wake-lock/. This isn't a feature for service workers.

I don't believe any browsers support wake-lock yet.

[adamburr100]

Thanks @jakearchibald

So if I understand you correctly, it is currently impossible to do what I need to do using a browser app.

I should give up my PWA and switch to producing a native app, right?

[jakearchibald]

@adamburr100 I don't know the relative priorities & timelines of the features you're trying to achieve, but if a required feature is impossible on a given platform in the timeframe you're beholden to, then I agree that the platform in question is a poor target for you currently.

[tyrex1975]

I didn't want to put +1, but we have a very strong use case for background GPS here too.

The scenario is similar to others mentioned - mobile workers out and about, central control seeing where they are, dispatching workers to locations in a dynamic visit-allocation environment.

We made the decision to build our app as a PWA long before the term PWA existed, back in the days of inconsistent browser storage standards, polyfills everywhere etc., so to see native features gradually appear and become standardised in browsers over time has really helped validate our decision to proceed down this route.

But live tracking is a Very Big Deal commercially these days (Google 'mobile workforce management' and try to find a site that doesn't mention live tracking), and unfortunately we keep having to look over to the dark side (native) in order to achieve our technical aims.

To have genuine background geolocation, installed from the web page and available even when the device is screen locked would be a huge positive.

[CharlBest]

We also have a need for tracking users in the background, with their permission, without having the PWA open. I like Jake's suggestion about showing a fixed notification tray item to show the app is open (even that the app is using geo-location) and clicking it or swiping it away disposes of the service worker.

[HarelM]

I too have the same problem. I would like to allow users to record their cycling/hike/drive and keep the mobile phone battery in a good shape for several hours - this means the screen need to be turned off.
I'm currently using (Cordova for this)[https://github.com/mauron85/cordova-plugin-background-geolocation]. I believe PWA is a better approach, but this is currently my first concern that doesn't allow me to migrate to PWA.
BTW, my site is here: https://israelhiking.osm.org.il/

[anssiko]

The work is resuming in the context of next-gen Geolocation Sensor. Please see https://github.com/w3c/geolocation-sensor/pull/30 and provide your feedback there. Especially helpful would be to understand whether the current use cases capture your requirements. Thank you!

[marcoscaceres]

Maybe we should close and lock this thread, and point people to the above?

[marcoscaceres]

Actually, it’s already closed. Would just need to lock 🔒

[ghost]

What is the status? Is there a way to add location tacking within a PWA by now?

[tomayac]

Nothing has changed so far, Navigator.geolocation is still where we are at the moment.

[ghost]

@tomayac do you have any clue that what is stopping them to do so? From my understanding I see the future of entire software/IT industry as PWA for the upcoming decade. Moreover if we see a growth in Chrome OS then this will be again a big plus. 💃 As we are already seeing major segments of google has already started using PWA aggressively with products like drive, YouTube, YouTube music etc. 😮 I believe giving flexibility of using all native features of android through JavaScript will change the way we see software/application and will allow developers to rely on a single technology, it's updates and it's community. 😄 ✌️

[marcoscaceres]

You are preaching to the choir, @lovishagg - and we all feel the same level of passion about empowering PWAs to do amazing things. However, this is very complicated from a privacy and security standpoint. It's going to take a while to sort out and for us all to come to some agreement to move this forward.

[ghost]

@marcoscaceres I understand that user privacy and security are among the major things which none of us would like to compromise on. But from my understanding of technologies, giving a hold of things which are possible through one technology to another as well, doesn't change a lot of things there. If we keep the permissions and notification alerts of a PWA, consuming the GPS data intact I believe we are doing no harm but just enabling a few APIs through non native environment. But since you say that it's more complicated than what's mentioned, I believe you and would wait like all others in the queue to implement it within my code base and start developing a native app just for the sake of unavoidable use case of having background location access. Thanks. ☮️

[Zibri]

Someone will have to explain me why this has not been implemented yet.
Web Apps need authorizations.
One I give it I am willing to activate that function.
Period.
So today you force people to code an "app" for 3-4 different OS which includes some sort of web browser which load and index.html while you should just enable thi fricking function (and all possible others).
The only reason that comes to mind is that they try to keep the "store" alive since webapps give too much freedom to coders.

[ghost]

Agreed @Zibri We as developers should be given freedom to code in whatsoever language/environment we want rather than big hardware manufacturers deciding it for us. And on top of that when they say you definitely need a mac in order to properly test and deploy your app on an iphone and the alternatives left are very low due to their so called "secure" systems.

[marcoscaceres]

This is spinning off topic. I'd suggest we lock this issue.

[hubyhuby]

+1
NEED
Please make it possible to access GPS from the background worker.
This is the number ONE feature request for my customers using PWA.
There are so many use cases that I don t want to spam this thread!

SECURITY
I don t see any security problem, PWA are now like regular apps, they ask you permissions! So there is NO differences...
PWA could be even BETTER at security than regular android or IOS apps , asking :
"This is using geo in the background and may use more power : YES/ NO"

[biju-ps]

+1

[Deltahedron]

Please

[saburo70]

Use Case : Starting to implement an app for Sailboat racing (more than that, but just to give the context) in which only GPS is monitoring the competition. Deciding if it makes sense to go the PWA route (it does for plenty of reasons non GPS related).
I cannot lose tracking if a user answers the phone or locks it, because that would potentially make him miss a waypoint and being eliminated from the competition

[JamesTheAwesomeDude]

How do you think the privacy and security aspects of this should be handled?

Especially on mobile, screen space is limited. A permanent indicator like a notification might be too much

FWIW, I think that might be an _extremely_ reasonable way to handle it.

e.g. Google Maps (during active navigation) and Waze (_whenever_ it's runnning) do exactly this: and I'd say that if you "make" the app display a conspicuous location, that's far preferable to allowing it to discreetly siphon location data without much ado (as e.g. the Google Location Services are uniquely privileged to)…

The status-quo-bar for "respects privacy" on e.g. Android is quite low at the moment, but I think that "have a background-notif up _while the app is monitoring your location_" would leave nobody feeling violated, while not being that visually-disruptive.

The only cases I can come up with offhand in which a background-notif-during-location-access à la Waze might be a _bit_ visually-much are:

• someone's e.g. re-implementing the entirety of Tasker as a PWA
• Geofencing _per se_ (which might end up being its own, separate can of worms)

But in all other cases, I think that this is the only natural solution. Perhaps it could be augmented by requiring the app to be re-opened to re-access GPS after it's closed its access (and thus vanished its notification)?

(My use-case is: I've created a bike-ride tracking "webapp" in just a few hundred lines of JS; it's so much nicer of a development environment than the whole SDK mess; but I would _really like_ to be able to allow users to turn their screens off during the ride while still collecting telemetry. This seems like such a natural thing to expect!)

[ingenix21]

After having read the whole thread I conclude without fear of being wrong, but I perceive from W3C a refusal for the development of the "geolocation in the background managed by service worker" and even more as crazy to propose https: //w3c.github.io/wake-lock/ as a solution. the W3C mentions privacy and security as the main obstacle, but perhaps that security and privacy is not "violated" by millions of applications that exist in the app store that use geolocation in the background, because that is what We speak, they also mention that the implementation is not so easy, but if geolocation is already implemented, you just have to activate it in the Service Worker!. Well, they are seeing obstacles where there are none, really the only argument I can find for such a refusal is that the W3C does not want the PWA to be able to develop applications as native applications do, if not, because they try to block this thread so vehemently.

[Tom333Trinity]

@JamesTheAwesomeDude @chaals @LJWatson My heart is truly breaking :-(

The fifth birthday of this topic has come and gone yet somehow we've managed to maintain the rage; well done. By this post alone regardless the many censored redactions by the @marcoscaceres cancel culture the voice of the people is crying out in the face of shameless falsehoods of "other priotities" and "insufficient interest".

Because of this topics and the many others to fora such as StackOverflow: -
https://stackoverflow.com/questions/44233409/background-geolocation-serviceworker-onmessage-event-order-when-web-app-regain/46210408#46210408
and
https://stackoverflow.com/questions/55290691/is-there-way-to-track-user-current-location-within-service-workers-in-pwa-while/55291929#55291929

It behoves W3C to explain their rationale, nay excuses, for not responding to such legitimate and modest requests for essential PWA functionality.

I can easily exlain to @ingenix21 why standard geolocation API is unsuitable for ServiceWorkers but we need to focus on the proven and for 5 years unchallenged TravelManager solution

Apple has green lights and read lights to unveil background functionality to the user. User permission is an issue easily solved once we have a solution that has been at hand for FIVE YEARS.

Rule 1. Nothing happens if and instance of Chrome is not running Dadaa!

Can someone, ANYONE, please tell me why W3C aren't doing this???

If only I wasn't censored from so many forums I can certainly tell you in few words why the WakeLock and dreamtime GeoLocation sensor are completely infeasible.

How to we escalate this issue over the corruption and/or incompetence of those involved at W3C?

[pperzyna]

+1

[JamesTheAwesomeDude]

I do have to echo the sentiment others have expressed here — that the "privacy and security" concerns seem… disingenuous, at best, given what's going to come out of the upcoming Geofencing API (read: Google et. al. gaining even more and broad surreptitious access to sensitive user data).

If they're offering something like this, I think we can all be sure that the service _powering_ that API is not going to get any kind of perma-notification w/r/t its background location access…

(The end result? Apps can only get background location access _if_ the user gives Google indefinite access to theirs — yielding something like the Location Services fiasco, but now the exclusive background-location API for PWAs: disabling Google's access will actually _cut off_ all these 3rd-party apps'…)

[jakearchibald]

Locking this in favour of https://github.com/w3c/geolocation-sensor/issues/22.

This repo is focused on core elements of the service worker spec. Features built on top of service workers happen in other specs, and often by other working groups.

In this case there are already other groups for geo-related things, and system lock related things.

The path forward here looks exactly the same as it has for 5 years. A system lock would allow a tab to use existing geo APIs while the phone is on standby. All of this is already designed, it just needs implementing.

If we need a solution targeted to geo, we could have a system that records position in the background, and delivers that data to the service worker, in bulk, when the user next visits the origin. This system isn't designed, and comes with significant privacy issues. This isn't a problem to be solved within this repo, or by this group.

This group will reject changes to the service worker core that allows the service worker to be continually alive, particularly while the site is closed, as this would present a huge privacy abuse vector, and unnecessary battery use.