createSelector call other selector with parmeter returned from the state

[nep7un]

Hi,

I'm trying to achieve the same with selectors, but I don't know how to call the dependant selector with a parameter returned from the state.

    this.product$ = this.store.select(selectProductById(this.id)).pipe(
      filter(product => !!product && !!product.collection),
      switchMap(product => {
      return this.store.select(selectProductsByCollection(product.collection.key)).pipe(map(products => {
        return { ...product, relatedProducts: products };
      }));
    }));

here is what I tried but it's failing with state is undefined.

export const selectProductByIdWithRelatedProducts = (key: string) => createSelector(
    selectProducts,
    selectProductById(key),
    (productState, currentProduct) => {
        if (currentProduct && currentProduct.collection && productState) {
            return {...currentProduct, relatedProducts: selectProductsByCollection(currentProduct.collection.key)(productState)}
        }
    }
);

this is the stack trace, what am I doing wrong?

ERROR TypeError: state is undefined
    selectIds ngrx-entity.js:19
    _args ngrx-store.js:566
    defaultStateFn ngrx-store.js:566
    memoizedState ngrx-store.js:666
    memoized ngrx-store.js:544
    memoizedProjector ngrx-store.js:663
    memoized ngrx-store.js:544
    defaultStateFn ngrx-store.js:567
    memoizedState ngrx-store.js:666
    memoized ngrx-store.js:544
    _args ngrx-store.js:566
    defaultStateFn ngrx-store.js:566
    memoizedState ngrx-store.js:666
    memoized ngrx-store.js:544
    selectProductByIdWithRelatedProducts product.selector.ts:46

[david-shortman]

Two ways to go about this. One, I explained in this thread. You can create a selector that delays the collection of a parameter.

Second, you could get a reference to the global state and provide it to the selector:

export const selectProductByIdWithRelatedProducts = (key: string) => createSelector(
    state => state, // select global state
    selectProducts,
    selectProductById(key),
    (globalState, productState, currentProduct) => {
        if (currentProduct && currentProduct.collection && productState) {
            return {...currentProduct, relatedProducts: selectProductsByCollection(currentProduct.collection.key)(state)}
        }
    }
);

[nep7un]

thanks @david-shortman, I didn't know how to get global state, it 's working perfectly!