Given Situation:
In my coding practice, I employ a
signalStore(withEntities<Entity>() /*...*/)There are instances where I need to initiate additional updates whenever an entity in the store undergoes addition, modification or deletion.
I am interested in utilizing an effect() in this scenario, but I am yet to find a straightforward and graceful way to identify what changed since the last invocation of the effect function.
Furthermore, I do not have access to the previous state of the store (similar to the functionality provided by Vue's watch()) for comparison purposes.
Any suggestions on how to approach this challenge effectively?
My preference would be to implement something along the lines of
watchEntities(store, (updated: EntityId[], added: EntityId[], removed: EntityId[]) => {
// This function is called like an effect each time there is a change in the store, allowing me to synchronize other components with these entities as needed
};
An AI recommended a solution involving:
toObservable(store).pipe(
startWith(null),
pairwise()
).subscribe(([prev, current]) => {
if (prev === null) return; // Skip initial emission
// ... which involves quite a bit of code to identify the changes ...
Therefore, it seems reasonable to enhance my methods of modification in order to trigger the necessary actions automatically.