Ngx-bootstrap: Typeahead performance very degraded in version 5.0.0 vs 4.3.0 when there are many items in typeahead results

[slubowsky]

Bug description or feature request:

Typeahead performance very degraded in version 5.0.0 vs 4.3.0 when there are many items in typeahead results

Plunker/StackBlitz that reproduces the issue:

See https://stackblitz.com/edit/angular-1kywuq

Simple demo with 2000 strings, 1000 showing. Using version 4.3.0 typeahead results appear almost instantly. Using version 5.0.0 (or 5.1.0) it takes 4-5 seconds to appear.

Note that in my actual use case (which uses objects not strings) it went from maybe 1 second using version 4.3.0 to something like 30 seconds using version 5.0.0 - much worse then demonstrated by this demo - but I think this already shows enough of the issue without my trying to reproduce the exact case.

Versions of ngx-bootstrap, Angular, and Bootstrap:

ngx-bootstrap:
5.0.0 - 5.1.0

Angular:
8.0.3

Bootstrap:
4

Build system: Angular CLI, System.js, webpack, starter seed:

cli and stackblitz

[andrefdg]

The same issue here. Any news on this subject? We have a productive app in Angular 8, and so we have to use the newest versions ( 5.x.x ) of ngx-bootstrap. Any solutions? 🥇

[andrefdg]

Hi,
Any update on this issue?

[daniloff200]

I expect, that this can be fixed with https://github.com/valor-software/ngx-bootstrap/pull/5589, and should be available with the latest version, it's 5.5.0

@andrefdg can you try it?

[slubowsky]

@daniloff200 There is I think definite improvement since version 5.0.0 but trying the stackblitz example referenced above https://stackblitz.com/edit/angular-1kywuq you can still see a noticable difference between version 4.3.0 and 5.5.0. With 4.3.0 you see typeahead suggestions almost (but not quite) instantly when you type a letter into the input , with 5.5.0 there is still a much more noticeable lag of several seconds until results show up.

[daniloff200]

Well, I see...
At least, for now, that's all, what was done related to it, unfortunately :(

[andrefdg]

@daniloff200 Thanks for your answer! It is better, but far from 'good', as @slubowsky has said. I think this issue should continue 'open' while the typeahead takes more time to show sugestions than the time needed to fecth the info from the server :)

[ddfourni]

I think the "can be closed?" label should be removed from this issue.