As a user I want to receive a notification when a new slot appears

[stayradiated]

I am considering a notification system, so you can get an alert when a supermarket releases new slots. It would be a challenge to implement a notification system that is actually useful to people.

Occasionally, there will be a glitch in the response from the supermarkets, and it will appear that there are suddenly no slots available, or every day has slots. This will cause issues.

I’m thinking something along the lines of:

look at the next X days
only send a notification if there have been no slots in those X days for at least Y hours
and the number of slots has increased from 0 to Z slots
and the number of slots has been stable over 5 minutes (i.e. not a glitch)

I think I can also get notifications to work without needing a server, using the Notification API and Service Workers…

[stayradiated]

So, it looks like iOS doesn't support web notifications at the moment... Not having mobile notifications are a deal breaker.

I am going to stand up a server to send emails instead.

[stayradiated]

I'm thinking that when someone subscribes to notification, they will be able to choose:

• Which supermarkets to monitor
• How many days in advance to check (i.e. only alert me if a slot is available in the next 3 days)

There are other variables I need to consider as well:

• Sometimes only 1 slot becomes available, it might be worth only notifying if at least 3 slots are available.
• Sometimes the supermarkets can glitch out, and show a bunch of available slots, but the next I check the website they have all vanished.