React Native on macOS or on web - broken width and month not changing

[rdewolff]

The library is not working when compiling a react-native project for macOS (Catalyst for example).
It's not working either when using react-native-web version.

The following elements are not working:

1. The width of the day header is not correct
2. The scroll is hard to test in these conditions, but it seems to not be able to trigger a next month change when you scroll past a certain amount of time horizontally.

Please find a video illustrating the first examples:

Steps to reproduce:

• create a react-native-web repository (u can use boilerplates like https://github.com/infinitered/ignite that support iOS/android and web
• add react-native-week-view package
• fix the issue reported on Deprecated usage of ViewPropTypes props #196
• include the <WeekView... /> component on a page
• try to render it on a web page

Notes

• It could be some simple width and height calculation to update and that would make it work 🤞

[pdpino]

@rdewolff I'll check this out ASAP

In the broken web app, where are events placed in the screen? For example an event in the central week, the week before and the week after.
Could you show a screenshot/gif with those?

[rdewolff]

I haven't added meets on the first test I did. Let me give it a try and get back to u

[pdpino]

@rdewolff I was able to reproduce it and display some dummy events, so don't worry:

[rdewolff]

Aaah great, you got a setup working 🥳

[rdewolff]

I just tried to display some events in the grid but did not get it working. Did you already do some fixes @pdpino to get your event displayed?

[pdpino]

TL;DR: I fixed some things, but is still not working 100%, probably due to an upstream bug from react-native-web VirtualizedList. Demo:

(btw the cursor is not moving because I was scrolling with the wheel)

---

Details:

There are multiple things in the initial example that were wrong:

1. Header does not have the appropriate width
2. All the grey horizontal grid lines are rendered at 00:00hrs
3. Vertical scrolling works, but the initial scroll to the startHour is not performed (i.e. you cannot call scrollTo() for the ScrollView ref)
4. Horizontal scrolling is broken
   4.1 The initial position should be today (in my example would be May 6), but the initial position shows April 21
   4.2 You cannot scroll past certain dates to the right or left
5. When scrolling the grid horizontally, the header does not follow the grid smoothly (i.e. animated)

What I did:

1. 👍 Compute the header width using the size of the window
   • required working on top of this recent PR Refactor: compute WeekView width dinamically #189
2. 👍 Grey gridlines are now properly rendered throughout the grid (was a simple flex issue)
3. 👍 The initial vertical position is fixed, and the vertical scroll works properly
   • Note: this required constraining the ScrollView's height to height: '100vh' (100 viewport's height, web only)
4. VirtualizedList and FlatList have shown issues in react-native-web (for example see a list of issues here: Updated VirtualizedList vendor files (with FlatList, SectionList) necolas/react-native-web#2241 (comment))
   • 4.1. 👍 The initialScrollIndex behavior was fixed --> the week starts pointing to today (see gif)
     • I needed to install the 0.18 preview version of react-native-web (yarn add [email protected], see preview here: 0.18 preview release necolas/react-native-web#2248)
   • 4.2 👎 👎 The scrolling is still constrained to 5 pages (weeks), from April 18 to May 22 (see gif)
     • Culprit: the onMomentumScrollEnd event from the horizontal VirtualizedList is not being triggered
     • We need that event to add pages (weeks) dynamically to the left and right
     • In the first render, we show 5 pages (those are the only pages shown in the gif)
     • I tested a small VirtualizedList example, and I think this is an issue from react-native-web (I can provide more details for a small repro)
5. 👎 Could not make the animation smoother (though, the horizontal scrolling should be resolved first anyway)

4.2 is probably a dealbreaker for most apps. We should corroborate if it is a bug from react-native-web; hopefully they will have a workaround soon

[pdpino]

Did you already do some fixes to get your event displayed?

@rdewolff tbh I don't remember if I had already made a small fix for that demo 😆

I made a draft PR with the fixes so far

[rdewolff]

Concerning 4.2, is there a way to use an alternative to onMomentumScrollEnd?

[pdpino]

The options I can think of are not good, e.g.

• onScroll event
  • Is triggered too often (once per frame, used for UI events) --> would lag the whole swiping interaction
  • Currently we use it to sync the grid with the header (bullet 5)
• onEndReached event
  • This could work on one side of the calendar (left or right)
  • but there is no onStartReached --> would not work on the other side (right or left)
• Using a library implementation instead of VirtualizedList
  • This library implements bidirectional infinite scrolling, but does not support horizontal: Horizontal flatlist? GetStream/react-native-bidirectional-infinite-scroll#5
  • RecyclerView, though they do not support bidirectional infinite scroll yet: Add support for bidirectional infinite scrolling Flipkart/recyclerlistview#647
  • Also in these cases we may encounter unexpected issues, e.g. with animations, etc

[rdewolff]

So our best bet might be to wait for react-native-web to support onMomentumScrollEnd.

Maybe this comment is related to our issue: expo/expo#16822 (comment) ?

[rdewolff]

How can we get this issue moving forward?

[pdpino]

How can we get this issue moving forward?

PR #201 will fix up to 4.1.

As to 4.2, I'm afraid without scroll events in web there is not much more we can do. I see a lot of attention in rn-web, (e.g. necolas/react-native-web#2249, necolas/react-native-web#2241), hopefully they will have a fix soon

On the side, I'm implementing some performance improvements, and that might include migrating to recycler-list-view, which should support rn-web scroll events. Although these changes are taking me a bit longer. (I'll probably open a separate issue regarding this soon).
UPDATE: See #209, we are not migrating to another library for now.

[rdewolff]

PR #201 was merged 🥳
necolas/react-native-web#2249 is still open 👀
necolas/react-native-web#2241 is done ✅

[pdpino]

@rdewolff necolas (rn-web 's author) commented:

those of you who need these events will need to implement and submit PRs for. I do not plan to work on adding these features myself.

I cannot work on that right now.

---

To recap, I think the options are:

1. wait for react-native-web to support scroll events

or wait for other libraries, e.g.:

2. react-native-bidirectional-infinite-scroll, does not support horizontal
3. recyclerlistview, needs bidirectional scrolling

with 2 or 3 we could try to make the change only for web (instead of web and mobile), if that's simpler. In any case, have in mind is a big refactor and may cause conflicts with other stuff (animations, etc)

[rdewolff]

The current workaround is to add navigation button to navigate to previous or next week.

[rdewolff]

Just found this https://github.com/Flipkart/recyclerlistview
Is it something we could use @pdpino ?

[pdpino]

Sorry for the late reply.

@rdewolff recyclerlistview does not support bidirectional infinite scrolling: Flipkart/recyclerlistview#647 (comment)

They implemented a fix for VirtualizedList, and is published in a fork of react-native: facebook/react-native#29466 (comment). Using this might fix the problem?