How can I force update React.memo child component? - reactjs

Question

My main functional component performs a huge amount of useQueries and useMutations on the child component hence I have set it as React.memo so as to not cause re-rendering on each update. Basically, when new products are selected I still see the old products because of memo.
mainFunction.js
const [active, setActive] = useState(false);
const handleToggle = () => setActive(false);
const handleSelection = (resources) => {
const idsFromResources = resources.selection.map((product) => product.variants.map(variant => variant.id));
store.set('bulk-ids', idsFromResources); //loal storage js-store library
handleToggle
};
const emptyState = !store.get('bulk-ids'); // Checks local storage using js-store library
return (
<Page>
<TitleBar
title="Products"
primaryAction={{
content: 'Select products',
onAction: () => {
setActive(!active)
}
}}
/>
<ResourcePicker
resourceType="Product"
showVariants={true}
open={active}
onSelection={(resources) => handleSelection(resources)}
onCancel={handleToggle}
/>
<Button >Add Discount to Products</Button> //Apollo useMutation
{emptyState ? (
<Layout>
Select products to continue
</Layout>
) : (
<ChildComponent />
)}
</Page>
);
ChildComponent.js
class ChildComponent extends React {
return(
store.get(bulk-ids).map((product)=>{
<Query query={GET_VARIANTS} variables={{ id: variant }}>
{({ data, extensions, loading, error }) => {
<Layout>
// Query result UI
<Layout>
}}
</Query>
})
)
}
export deafult React.memo(ChildComponent);

Answer 1

React.memo() is useful when your component always renders the same way with no changes. In your case you need to re-render <ChildComponent> every time bulk-id changes. So you should use useMemo() hook.
function parentComponent() {
... rest of code
const bulkIds = store.get('bulk-ids');
const childComponentMemo = useMemo(() => <ChildComponent ids={bulkIds}/>, [bulkIds]);
return <Page>
... rest of render
{bulkIds ?
childComponentMemo
:(
<Layout>
Select products to continue
</Layout>
)}
</Page>
}
useMemo() returns the same value until buldIds has not changed. More details about useMemo() you can find here.