Re: [w3c/manifest] Clarify circumstances in which BeforeInstallPromptEvent.prompt() may be called (#691)

We must carefully distinguish *User Agent Options* (the Options 1–4 [above](https://github.com/w3c/manifest/issues/691#issue-332248820)) and *Spec Proposals* (the Proposals 1–3 [above](https://github.com/w3c/manifest/issues/691#issuecomment-397180002)). Here, we're just debating the spec proposals, which are three different ways we could go with the spec requirements, and then UAs would have (in any proposal) a number of Options available.

@frlinw You're arguing for a particular UA option (1) but that's a debate you need to have with individual browser manufacturers (including me, on Chrome, but not here). We can't mandate a particular UI in the spec, only the requirements around the API. Note that all 3 Proposals allow both Options 1 (developer opt-in) and 2/3 (automated prompt not linked to `BeforeInstallPrompt` event).

We can't specify that browsers are *not* allowed to show an automated prompt not linked to the `BeforeInstallPrompt` event, because that's browser UI and they can do anything they want.

Now putting on my browser manufacturer hat (Chrome):

> To me, UA components should not (automatically) invade webapp land. What is the downside of the option 1 (opt-in) ?

It's mainly that most sites aren't currently using `BeforeInstallPrompt`, and we (browser manufactures) still want to let users know that it's installable. I agree the current infobar that appears along the bottom of the screen in Chrome for Android is a bit heavy-handed, and we are currently exploring ways to make it a more subtle icon in the address bar (as Firefox has today). That "add to home screen" icon in the address bar, as well as the "add to home screen" menu item, are essentially the same thing as an "automated prompt", in that they are install UI shown by the browser without the developer's explicit request, just a lot more subtle.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/manifest/issues/691#issuecomment-408773864