tl;dr: We have two existing features (multipackage xpis and the InstallTrigger api capability for installing multiple xpis in a single call) that are not widely used. I would like to remove them to reduce complexity in the add-ons manager.
Background: The XPI file format is used for several types of add-ons including extensions (both webextensions and the older xul and bootstrap ones), themes, and language packs. One of the more obscure features of the format is "multi-package" xpis which are pretty much what you might guess from the name: a collection of other xpis all bundled into a single file. And then we have the InstallTrigger api, which provides a way to install xpis from content (guarded by permissions prompts of course). This is the api that is is invoked when you press the "Add to Firefox" button on an addons.mozilla.org page but it is also documented for use by others. This api is an ancient one that we inherited from Netscape (!!) though it has never been standardized or implemented in other browsers. Among other things, InstallTrigger provides a way to install multiple xpis with a single api call. Unfortunately we don't have any telemetry available about how frequently these two features are used but empirically they appear to be very uncommon. However, they are responsible for a good deal of complexity in the add-ons manager and, more urgently, they complicate the UX design for current efforts to display detailed permissions prompts to users when they install a webextension. Rather than deal with the UX design and corresponding implementation complexity of install operations that include multiple webextensions that need to be individually approved by the user, I'm proposing that we drop support for multi-package xpis and restrict the InstallTrigger api to only allow installing a single xpi at a time. I would like to do this in Firefox 53. -Andrew _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform