add isDisabledDate

[stinger567]

added the ability to enable and disable dates, using isDisabledDate function: #110

If this is not how you wanted it implemented, and would prefer a different way let me know and I can change it.

[probablykasper]

The thought was to havs isDisabledDate as the API. Having it as an implementation detail might just be unnecessarily bad performance

But I see now that you might want to reactively update the enabled/disabled dates (right?), so then I'm not sure what API is best. I don't love the idea of having to create an array of disabled dates

[probablykasper]

I think an isDisabledDate prop is best

[stinger567]

Yeah, I would want it to be reactive. I re-worked it to use a isDisabledDate prop, let me know if this is better?

[probablykasper]

Looks good, but it's still possible to select disabled dates by typing, using arrow keys and probably by switching the month/year

How it should probably work:

• When updating from oldDate to newDate:
  • If newDate is newer, go forward to the next enabled date
  • If newDate is older, go back to last enabled date

[stinger567]

That was an oversight on my part, I have put in a fix that should now prevent a disabled date from being selected by typing or by the arrow keys.

[probablykasper]

I found an issue when using the DateInput. When setting the DateInput's value, it's not affected by isDisabledDate for some reason (added a button to test it in my latest commit)

It seems like the updated DateInput value never reaches the DatePicker, so they go out of sync. Surely not caused by your code, I wonder if it's a Svelte 5 issue maybe

[stinger567]

Oh I see now, yeah I did overlook that case.

[probablykasper]

btw, if you feel like converting to runes syntax would fix it, I have nothing against dropping Svelte 3/4 support

[stinger567]

After looking at it more, updating to runes wouldn't help, DatePicker is behind an if statement so it doesn't load till the date input is clicked to open it. Setting the date through the DateInput will never pass the date to the DatePicker. Also since DatePicker can be used separably, the date just needs to be check in both DateInput and DatePicker. I moved the toValidDate function to the date-utils file, then used it in both DatePicker and DateInput, it fixes the issue. If you would prefer it done a different way let me know.

[probablykasper]

Ah makes sense, very great work!

[probablykasper]

Very great work