Web App Launch Handler #683

Braw mornin' TAG!

I'm requesting a TAG review of Web App Launch Handler.

Web app launch handler is new launch_handler manifest member that enables web apps to customise their launch behaviour across all types of app launch triggers.
We found that almost all "launch" use cases could be covered by a select few fixed rules (for example, "choose an existing window in the same app, focus it, and navigate it to the launched URL"). This launch_handler proposal enables sites to specify a set of fixed rules without having to implement custom service worker launch event logic, which should satisfy most use cases, and simplify the implementation in browsers and sites.

This is a successor API to Declarative Link Capturing which has its own completed TAG review.

• Explainer: https://github.com/WICG/sw-launch/blob/main/launch_handler.md
• User research: Positive developer feedback from the DLC origin trial wanting to continue using the navigate-existing-client behaviour.
• Security and Privacy self-review: Web App Launch Handler: Security and Privacy self-review
• GitHub repo: https://github.com/WICG/sw-launch/issues
• Primary contacts (and their relationship to the specification):
  • Alan Cutter @alancutter, Google
  • Matt Giuca @mgiuca, Google
• Organization/project driving the design: Google
• External status/issue trackers for this feature:
  • https://www.chromestatus.com/guide/edit/5722383233056768
  • https://bugs.chromium.org/p/chromium/issues/detail?id=1231886

Further details:

• [ X ] I have reviewed the TAG's Web Platform Design Principles
• The group where the incubation/design work on this is being done (or is intended to be done in the future): WICG
• The group where standardization of this work is intended to be done ("unknown" if not known): Web Apps WICG
• Existing major pieces of multi-stakeholder review or discussion of this design: Declarative Link Capturing TAG review
• Major unresolved issues with or opposition to this design:
• This work is being funded by: Google

You should also know that...

launch_handler is a piece of the larger web app link handling puzzle:
PWA Link Capturing and URL Handling: The New Taxonomy

We'd prefer the TAG provide feedback as:

💬 leave review feedback as a comment in this issue and @-notify [github usernames]