Update the reference to getStableId in VirtualRenderer when the DataProvider is changed

[DevopsElectricJukebox]

This is a bugfix for the case when the dataProvider is changed, and may provide entirely different data. The VirtualRenderer needs to update its own reference to getStableId to ensure that it uses the correct IDs for the components it creates.

[naqvitalha]

_fetchStableId always refers the the latest dataProvider. Check here: https://github.com/Flipkart/recyclerlistview/blob/master/src/core/RecyclerListView.tsx#L157 . What issue were you noticing?

[DevopsElectricJukebox]

This is in the function used to sync the virtual renderer with a new data provider. The virtual renderer keeps a reference to a getStableId function which must be updated when the data provider changes. If this is not done, then it will fail to correctly associate indexes with stableIds when the new data provider returns different stableIds for each index - e.g. if an item is inserted at the start of the data array.

I did not find any other place in the code where _fetchStableId could be updated when the data provider is changed, and this seems like the best place to do it.

[DevopsElectricJukebox]

Hi,

You can test this bug by the following steps:

1. Instantiate a RecyclerListView with a DataProvider containing 1 item.
2. Change the DataProvider to one containing 3 items
3. The RecyclerListView will crash due to trying to look up the 2 new items using the old DataProvider's getStableId function.

Thanks.

[DevopsElectricJukebox]

Hi,

I will close this PR since this is actually not a complete fix. The addition of _fetchStableId is in the wrong place, and needs to be called under different conditions. I will consolidate changes and open a new PR for you to review.

Thanks.