How about retain prop? (easy & cheap Relay Classic caching behaviour)

[adjourn]

Would it make sense to implement a prop to disable GC (a'la Relay Classic behaviour) to this package?

I find it wasteful, even annoying to fetch all the data again & again in most of my own apps. Very few (browser) apps are very long-lived & I don't belive most of our apps ever get memory problems, especially if you don't target emerging markets (very low-end devices).

It would also be pleasantly flexible for different strategies, for example:

• List view - dynamic, updates often, don't retain: <QueryRenderer other={"props"}/>
• Single item view - retain it: <QueryRenderer retain other={"props"}/>

It would be very cheap because it would only be checked againts on componentWillUnmount or what?

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But how would one even implement this? I think something like this, haven't seen any side-effects so far..

_release() {
  // ... _rootSubscription & _pendingFetch code -> nothing to do with retaining data

  // reference to retained data ("protected" from garbage collection) - jackpot, add condition
  if (!this.props.retain && this._selectionReference) {
    this._selectionReference.dispose();
    this._selectionReference = null;
  }
}

I haven't 100% figured out yet how onError & onNext might affect retained data in different situations.

[robrichard]

@unirey sounds good to me. Do you mind opening a PR?

[robrichard]

I added the retain prop in the latest version 2.0.1. Please let me know if this works for your use case!