Deprecating this seems like a mess, because it is used quite often internally.

How about emitting a deprecation warning for the external users and making it a implementation Detail in KF6? Then we could clean it up at any time during the KF6 lifetime (if we don't need it anymore).

Looking at the usages I only see one in a KIO test, though it seems not that useful IMHO.

AFAICS the KServiceType class should be deprecated as well.

@dfaure But there are still usages in ApplicationTrader (the usage in KService should be deprecated as well, since it will not be useful in KF6)

(this was the part where I got stuck when using the deprecation macros, but I somehow was unable to find it when we talked in the meeting 😅 )

KService::List KApplicationTrader::query(FilterFunc filterFunc)
{
    // Get all applications
    KSycoca::self()->ensureCacheValid();
    KServiceType::Ptr servTypePtr = KSycocaPrivate::self()->serviceTypeFactory()->findServiceTypeByName(QStringLiteral("Application"));
    Q_ASSERT(servTypePtr);
    if (servTypePtr->serviceOffersOffset() == -1) {
        return KService::List();
    }

    KService::List lst = KSycocaPrivate::self()->serviceFactory()->serviceOffers(servTypePtr);

    applyFilter(lst, filterFunc, true); // true = filter out service with NotShowIn=KDE or equivalent

    qCDebug(SERVICES) << "query returning" << lst.count() << "offers";
    return lst;
}

Yeah that's because ksycoca still contains all sorts of service types: "Application" but also all others. So when querying that DB, we still need to filter on "Application". Once we get rid of non-application desktop files in ksycoca, we can also get rid of that filtering.

I guess that means deprecating KServiceType has to wait indeed.

Would the deprecation message I had originally in the KServiceTypeTrader deprecation MR (https://invent.kde.org/frameworks/kservice/-/merge_requests/71/diffs?diff_id=220762&start_sha=4c1e4fbb57df8273c19abb842aba528fe28f204f#f720654fa73490c7f3a67a876cb9a5bac40e0c35_33_32) be enough to inform users about this change?

Then we can clean it up when KF6 is branched.

Yep that message seems fine. You were right from the start :-)

First steps:

https://invent.kde.org/frameworks/kservice/-/merge_requests/118
https://invent.kde.org/frameworks/kservice/-/merge_requests/115

WIP branch, not finished yet: https://invent.kde.org/frameworks/kservice/-/commits/work/nico/servicetype/

https://invent.kde.org/frameworks/kservice/-/merge_requests/134