[w3c/payment-handler] Revisiting Payment Method specific filter/capability matching (#157)

Hi all,

At yesterday's meeting [1] we returned to the question of whether matching of payment method specific filters/capabilities happens in the user agent or the payment app. There were two topics:

 - How capabilities are identified (in data from the merchant)
 - Where matching takes place.

This issue is (for now at least) about the latter.

I think there is consensus that Payment Request API should indicate in relevant algorithms  THAT additional matching can take place according to payment method. I anticipate that PR API will not say WHERE matching takes place (user agent or payment app).

The current Payment Handler spec supports registration of payment app capabilities with the user agent with, I believe, the assumption that the user agent will do the matching. There are pros to this approach, including:

 * Payment apps don't have to implement matching
 * Payment apps do not learn about users transactions until selected by the user

There are also cons to this approach:

 * Simple string matching may not be adequate to address some use cases
 * Payment apps may not want to share user data with user agents
 * There may be challenges to keeping registration data up-to-date, especially if there
    are multiple instances of the payment handler (on different devices) that need to be updated.

After FPWD, I would like the payment apps task force to revisit this question of matching
to see whether we still wish to put forward an approach where matching is implemented
by the user agent, or more of a canMakePayment() approach where the payment app
returns a boolean (and where we are sensitive to privacy issues).
   
Ian

P.S. I started a new issue but this is also a continuation of some parts of the
closed issue 96 
  https://github.com/w3c/payment-handler/issues/96

[1] https://www.w3.org/2017/05/11-wpwg-minutes.html#item02

-- 
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/payment-handler/issues/157