[permissions] navigator.permissions.request (#48)

I want to give an insight on how different all the permission request works and tell the pro & con of each one them. mostly about the error feedback and what we can do about it

**First one is the notification API**

 Notification.requestPermission(
   result => { 
     // default, denied, granted
   }
 );

I think this is the worst, one single callback with a result string. And what da heck dose default mean?!
In chrome it means user dismissed the permission dialog if the default action is to prompt every time

if you dismissed then you are able to request a new permission again 

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**Geo Location API**

 navigator.geolocation.getCurrentPosition(
   Geoposition => { 
     // Geoposition {
     //   coords: {...}
     //   timestamp: 1443113866865
     // }
   },
   PositionError => {
     // PositionError {
     //   code: 1-3
     //   message: "..."
     //     PERMISSION_DENIED: 1
     //     POSITION_UNAVAILABLE: 2
     //     TIMEOUT: 3
     // }
   }
 );

In chrome if you dismissed the request then you think that the client has denied access forever. and you can not request any new permission until you refresh the page. unlike the other you can ask for a new permission again. So i think this one is bad. The other permission request API support asking more then once

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**Midi access**

 navigator.requestMIDIAccess([opts]).then(
   MIDIAccess => {
    // MIDIAccess {
    //   inputs: MIDIInputMap
    //   onstatechange: null
    //   outputs: MIDIOutputMap
    //   sysexEnabled: false
    // }
   }, 
   err => {
     // DOMException: An attempt was made to break through the security policy of the user agent.
   }
 )

This one is the only one that returns a promise. Me like! But i don't like the error response, happens for both dissmis and deny

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**User Media**

 navigator.getUserMedia(
   opts,
   MediaStream => {
     // MediaStream {
     // ...
     // }
   },
   NavigatorUserMediaError => {
     // NavigatorUserMediaError {
     //   constraintName: ""
     //   message: ""
     //   name: "PermissionDismissedError", "PermissionDeniedError"
     // }
   }
 )

Chrome went the extra mile and put a #<code.name>PermissionDismissedError on this one only and that is really grate for the developer. You can read more why this is good in a bug request over at [bugzilla][1]. I wish the rest of the permission request could give you this kind of feedback back to the developer. Especially for the geoLocation in chrome where you could accidently close the permission request and never been asked again

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Summary
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In Firefox you can never really dismiss a permission request, they have something called door hangers (i think) were you can "minimize" the request and respond again later in time. The button is called "Not now". I don't like this at all. the developer gets no feedback at all that the permission request was dismissed and leaves you with a "waiting for a response"... very bad if you are building a one-page application and 5 page/hours later you get a response back when this no longer is relevant 

I don't like how differently all this permission API works and now we have a chance to make it right and unify the navigator.permissions.request API

And here is how i think it should work:

The navigator.permissions.request method should return a promise and the rejection should return DOMError that can speak for all of the different permission request you can make. So I wish to get a PermissionDismissedError, PermissionDeniedError and a PermissionUnavailableError and maybe a PermissionTimeoutError for geoLocation

And if you dismissed the request then you SHOULD be able to make a new request.


  [1]: https://bugzilla.mozilla.org/show_bug.cgi?id=947266

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/permissions/issues/48