RLayerTileWMS refresh unexpectly about rlayers HOT 9 CLOSED

I am not very sure that this is a good idea, propsDiff is mostly a debugging aid.

This is an artificial edge case. Normally, you should have used useCallback on the map to prevent excessive refreshing. Maybe there are some optimizations possible, but it would be very bug prone and I don't think it will help a lot for any real-world use case. Also, you are not supposed to nest layers.

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Just imagine, in your case, what would happen if you had another nested level inside - for example with a feature - and its property did change depending on the map property. You would have blocked the propagation down the chain.

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Thanks for your time.

Considering this case

const App = () => {
  cont [count, setCount] = React.useState(0);
  return <RMap onChange={() => setCount(s => s + 1)}>
    <RLayerTile>
      <RLayerTileWMS url="https://example.com/wms" />
    </RLayerTile />
  </RMap>
}

After going throught some source code, i know that
RLayerTileWMS extends RLayerBase which eventually has base class PureComponent. When state in wrapper compoent(App) changes, RlayerTileWMS should not be renderred because all i'ts props (only url in this case) are not changing. But the componentDidUpdate did called. It makes me confusing... (Maybe the context is changing?)

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The context probably changes, but you are not supposed to be nesting layers at all. I don't want to optimize this case, as it will be very error-prone and it is an artificial edge case that forces an update of RMap component. This should have been a constant function obtained by useCallback - otherwise it will surely kill performance.

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Sorry for my copy&past mistake, in my minimum case, RLayerTileWMS is not nested.

const App = () => {
  cont [count, setCount] = React.useState(0);
  return <RMap onChange={() => setCount(s => s + 1)}>
      <RLayerTileWMS url="https://example.com/wms" />
  </RMap>
}

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Ok, now it is correct, but it is still an artificial case.

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If you submit a PR that does not touch the base classes, but only RLayerTileWMS, I will consider it. Do not use propsDiff, it is a debugging aid.

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I found this is a common render issue that in RLayerBase there is RContext declared, further in RMap which set the value of Context.Provider.

In this way, React.PureComponent was not acting as expected...

let me make a stackblitz example then...

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Yes, rerendering a layer would replace the context object. If your problem is only with the RLayerTileWMS, I prefer that you modify only this component. Currently, it will recreate the source, because the settings cannot be changed. This can probably be memoized.

Directly memoizing the context object could save rerenders, but it is a dangerous change that would have to be very thoroughly tested.

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