Implement debounce to improve performance

[danyill]

To improve performance with a large number of list items, I suggest using a debounce on the @input for the search box, something like:

function debounce(callback: any, delay = 250) {
  let timeout: any;

  return (...args: any) => {
    clearTimeout(timeout);
    timeout = setTimeout(() => {
      callback(...args);
    }, delay);
  };
}

  onFilterInput = debounce(() => {
    Array.from(
      this.querySelectorAll(
        'mwc-list-item, mwc-check-list-item, mwc-radio-list-item'
      )
    ).forEach(item =>
      hideFiltered(item as ListItemBase, this.searchField.value)
    );
  }, 500);

My use case is that the filtered list becomes unresponsive in a large (or even not so large file) when the full scd file's ExtRefs are shown in a single filtered list in the oscd-subscriber-later-binding plugin (in the subscriber view)

I found this article on debouncing/throttling helpful: https://blog.webdevsimplified.com/2022-03/debounce-vs-throttle/

This helps for moderate sized lists but not adequately for large lists but is probably worth doing any way. It is very likely that we should choose a number slightly lower than 500 ms (250? 300? 350? 400?)

This is for a file which has about 3620 ExtRef elements. Quite a few of these are "empty" but many relays fully expose their maximum capability in the quantity of ExtRefs they export.

IEC61850_GOOSE_2-section.scd.zip

I think this is a realistic scenario - we use schemes like this in production now.