Pass this.state.data to then(), catch(), andThen() and andCatch() functions for more powerful side effects

[nuschk]

Does it make any sense to have this.state.data available in those handlers? In my case, it's relevant for implementing an infinite scroller, where each fetch adds to the previous data and I need to somehow merge it.

Here's how that would look like:

const connections = {
  widgets: '/api/widget/?limit=20',
  loadMore: offset => ({
    loadingMore: {
      url: `/api/widget/?limit=20&offset=${offset}`,
      andThen: (res, meta, data) => ({
        widgets: { value: data.widgets.value.concat(res) },
      }),
    },
  }),
};

My current workaround is to pass a getData() function to loadMore() from the component, which works, but isn't nice.

On another note, I would like to have that data even in direct mapping functions (loadMore()above), so I can do things like optimistic updates.

And, 👍 for this very nice library, thank you for writing it!

[ryanbrainard]

Instead of passing getData() to loadMore(), what if you pass the actual data and then you'd have access to it in the andThen? Something like this:

onst connections = {
  widgets: '/api/widget/?limit=20',
  loadMore: (offset, data) => ({
    loadingMore: {
      url: `/api/widget/?limit=20&offset=${offset}`,
      andThen: (res, meta) => ({
        widgets: { value: data.widgets.value.concat(res) },
      }),
    },
  }),
};

[nuschk]

Yes, I tried that one. This leads to problems when calling loadMore() multiple times before it completes (which, e.g., when using react-virtualized, is normal, as the user is free to scoll on at full speed). You end up accessing old versions of data which have been updated since the call to loadMore.