OBKN-658 OrderDetails returns to first picklist item on every pick #264

kchelstowski · 2022-07-12T07:54:01Z

The ticket describes something else than Justin's videos, but that's okay and I'll describe why:

when Justin was recording those movies, he was using version before the refactor of OrderDetails component and that was a big issue connected to Carousel and FlatList: a nice discussion about this topic is here: link
To fix that (it seemed like for all people reporting that issue, the problem happened when their data was > 6 length) I just had to add useScrollview={true}.

BUT it was when using old, before refactor OrderDetails component. On new one it's true, that it always returned to first item, because initialPicklistItemIndex was passed to props wrongly and it was always 0 when console.loged inside Carousel (it was setting the intialPicklsitItemIndex state as the previous one, so in general it was setting that as the initial value, so 0).
Then another problem saw the light of the day - when I fixed initialPicklistItemIndex it turned out, that the Carousel 'doesn't see' that the state (initialPiclistItemIndex) updated, so in the beginning it was rendered a few times with 0 passed as props (before the getOrderDetails() function ended its work) and then it was passing the correct value, for example: 8 (but those renders were just a characteristic of React and there is nothing wrong about that - the wrong part was that the Carousel didn't react that firstItem was updated from 0 to 8 etc.).
I was wondering why and thought that maybe Carousel just doesn't re-render after the firstItem changes and yeah, the key was set (don't know why) as 3. I think it made Carousel not re-rendering when the firstItem changed from props.
After changing key to actual value of initialPicklistItemIndex the problem doesn't happen anymore - the Carousel updates the firstItem propely (it just re-renders)