Re: [Taler] Taler Android UX

[Torsten Grote]

On 2020-04-07 14:40, Christian Grothoff wrote:
>> [exchange selection]
> First time: - bank trigger (QR code, link on Bank-site) => Exchange 
> selection => Tos => ...

If there's a trustworthy exchange to pre-select, doing this might be
easier for users than being forced through exchange selection for their
first-time withdrawal. We could still show an onboarding dialog making
people aware of the possibility to change the exchange, but maybe only
for their second withdrawal?

> The /keys response of the exchange includes four fees for each 
> denomination.

Thanks! I now found it in the exchange info JSON I get from wallet-core
and implemented a simple page showing the fee structure of the current
exchange. A screenshot is attached.

> Well, 'big warning' may be an understatement (we could make it a 
> protocol violation and refuse to deal with the exchange).

If that's possible. Sure.

> But the real question is what those 'ground rules' should *be* (to
> improve UX while maintaining sufficient flexibility).

It would maybe help to understand the fee structure better.

So there's a withdraw fee per coin which adds up to a total withdraw
fee. Then, there can be a rounding loss if we can't satisfy the
withdrawal with the available coins. Couldn't we offer the user to
withdraw a bit more in this case to avoid this loss?

Then each coin also has fees for deposit, refresh/change and refund. The
last one is clear. Not sure when the first fee is due. Is this for
payments. Refresh is needed when a payment can't be made with the
available coins.

I don't yet understand why these operations incur different technical
costs for an exchange operator and thus need to separate. I also don't
understand why the fees need to be per coin. Ideally, the UI and cost
structures can be understood by users without knowing about coins.

Then there's wire fees per year. Are these always per year or are the
timespans flexible? For which operation are those fees charged?

>> Btw. it looks like the WebExtensions wallet and the exchange let 
>> you withdraw KUDOS without needing to accept the ToS. IMHO both 
>> should enforce that.
> Of course. The problem is that we are (still) lacking man-power for 
> the WebExtensions wallet.

Sure, but is the WebExtensions wallet silently accepting the ToS for the
user? If not, IMHO the exchange should enforce that ToS were accepted
before accepting a withdrawal.

Kind Regards,
Torsten

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