TODO: Cart items refreshing for every value change

[sebastianfdez]

Hi everyone.

Is this TODO planned to be solved soon ? We are facing some terrible performance issues within 100+ products baskets. The initial rendering is quite OK, but then, everytime we change a QTY, all the lines are re-renderer so the interaction is very slow.

spartacus/projects/storefrontlib/src/cms-components/cart/cart-shared/cart-item-list/cart-item-list.component.ts

Lines 32 to 39 in 91db098

	@Input('items')
	// TODO: currently we're getting a new array of items if the cart changes.
	// pretty annoying as it forces a repaint on the screen,
	// which is noticable in the UI.
	set items(items: OrderEntry[]) {
	this.resolveItems(items);
	this.createForm();
	}

Thanks a lot !

[Parthlakhani]

Tried reproducing the bug with 180 products in the cart, could not reproduce.

[hackergil]

Current solution does not work properly

• It caused a bug where the last product is duplicated with a quantity of 0
• On cart-item-list.component, we cannot modify cart item list this._items in version > 3.0 since we've activated strict mode and it freezes arrays and properties.

[Zeyber]

It doesn't look like all cart items are rendering on QTY change anymore. Only the item with the updated QTY which is what's desired.

[giancorderoortiz]

@sebastianfdez could you please share with us the average, max, mean cart size in your project? It would help us for testing purposes.

[giancorderoortiz]

This issue "appears" to be fixed.
I recreated a cart with 100+ items in it.
Upon changing quantities, I do see a delay of less than 5 seconds. The delay is random, but it's there.
Attaching some screen shots and video-recordings.
However, I do not see terrible performance as initially described in this ticket. ✅

It's necessary to have concrete performance specs and expectations regarding large carts so we can reproduce internally.

[giancorderoortiz]

dev_branch_may_17_2021_large_cart.mov

[giancorderoortiz]

qa_server_100_plus_cart.mov

[giancorderoortiz]

qa_server_profile-20210518T061752.json.zip

[giancorderoortiz]