Inconsistent behaviour when clearing search filter

[Lisakarolina]

In the grid view of the profile section, when a search term is entered in the input field, a subset of profiles is displayed as the search result, one of those profiles is selected and then then the search field is cleared again, the behaviour is inconsistent: Sometimes after clearing the filter the selected profile is scrolled back into view, sometimes it isn't.

Example to reproduce the issue:

1. Go to profile section on the planty site
2. Activate grid view.
3. Enter a search term in the search field, e.g. "weiß". At the moment the search term "weiß" will result in eight search results.
4. Clear the search filter, observe if the selected profile is scrolled back into view or if simply the beginning of the grid list is visible, the selected profile being visible only after scrolling.

Result: Behavior is unreliable, e.g. while profiles like "Weißdorn" and "Weißtanne" are scrolled into view, "Weißer Riesling" is not.

[sheepyhollow]

Apart from the technical aspect of this issue - iirc the 'search' is very quick and just filters some of the profiles' fields.

If we move over to lazy loading, e.g. a paginated loading, the functionality will likely not work as before as not all searchable items might be available in the store.

When discussing lazy loading in the past, I seem to remember that we ended up deciding not to do this json filtering in the frontend but implement search as a backend request. That was then and there might be other ways to do it, e.g. loading just a flat list of all necessary profiles with thumbnails and searchable fields only (but perhaps this is what the "flat-profiles" idea is about).

No suggestion here, but just some context that we talked about the profile search function some time in the past.

[Lisakarolina]

I came across this issue while implementing getting the search results from the back end (#2101). The new design is: Fields that are supposed to be included in the search are defined in the respective back ends on a model-by-model basis, the front end fetches the search results and displays them. A list with the flat profiles is only fetched for the purpose of displaying content in grid view, not for filtering according to search term. I wrote this issue more as a reminder, to keep track of existing inconsistencies, because when I first noticed it I thought it was caused by my changes...

[Lisakarolina]

After digging into it, it seems to me that this is happening: The trackBy function inside a NgFor loop is used to customize how Angular uniquely identifies an iterable, avoiding unnecessary DOM updates. The problem is that with multiple profiles the trackBy function in its current state doesn't uniquely identify profile cards anymore, which leads to unexpected behaviour (maybe because arbitrary rerendering is causing the solidProfileSelected directive to be re-applied, which changes selectedElements):

solid-frontend/libs/solid/profile/src/lib/components/grid/grid.component.ts

Lines 32 to 34 in 12abb3a

	public trackByFn(index: number, profile: Profile) {
	return profile.id;
	}