[TYPO3-core] RFC #8279: Bug: Sorting in fields of type "group", "MM=1" and "multiple=1" is not preserved

[Ernesto Baschny [cron IT]]

Hi,

committed to TYPO3_4-1 (rev. 3768).

Cheers,
Ernesto

Ernesto Baschny [cron IT] wrote: on 28.04.2008 14:56:

> Type: Bugfix
> 
> Bugtracker references: http://bugs.typo3.org/view.php?id=8279
> 
> ChangeSet reference for the fix by Kasper in TYPO3_4-2: 
> http://code.typo3.org/v4/changeset/3002
> 
> Branches: TYPO3_4-1
> 
> Problem:
> If I have a field defined like:
> 
>        'mitglieder_ag' => array(
>            'exclude' => 1,
>            'label' => 
> 'LLL:EXT:cronmm_ratsinfo/locallang_db.xml:tx_cronmmratsinfo_gremium.mitglieder_ag', 
> 
>            'config' => array(
>                'type' => 'group',
>                'internal_type' => 'db',
>                'allowed' => 'tx_cronmmratsinfo_ausschussgemeinschaft',
>                'size' => 20,
>                'minitems' => 0,
>                'maxitems' => 100,
>                'multiple' => 1,
>                'selectedListStyle' => 'width:100px',
>                'MM' => 'tx_cronmmratsinfo_gremium_mitglieder_ag_mm',
>            )
>        ),
> 
> that is with "MM=xxx" and "multiple=1", I am able to have a list where 
> the same record occurs multiple times, e.g:
> 
> uid_foreign=45, sorting=1
> uid_foreign=44, sorting=2
> uid_foreign=44, sorting=3
> 
> After moving the entry 45 down one item (to get the list "44, 45, 44"), 
> and I save the record, I end up with the following list:
> 
> 45, sorting = 1
> 44, sorting = 3
> 44, sorting = 3
> 
> So not the desired sorting (sorting=3 twice). To sum up, I cannot 
> separate the same uids: they will end up always being sorted in a "block".
> 
> 
> Problem:
> The problem comes from t3lib_loaddbgroup::writeMM(), which cannot handle 
> "multiple=1".
> 
> Imagine $oldMMs: 45, 44, 44 (the old order)
> the new $this->itemArray in t3lib_loaddbgroup::writeMM() is: 44, 45, 44 
> (the desired new order)
> 
> In t3lib_loaddbgroup::writeMM() TYPO3 will execute the following UPDATEs:
> 
> UPDATE tx_cronmmratsinfo_gremium_mitglieder_ag_mm SET sorting = 1 WHERE 
> uid_local=1026 AND uid_foreign=44
> UPDATE tx_cronmmratsinfo_gremium_mitglieder_ag_mm SET sorting = 2 WHERE 
> uid_local=1026 AND uid_foreign=45
> UPDATE tx_cronmmratsinfo_gremium_mitglieder_ag_mm SET sorting = 3 WHERE 
> uid_local=1026 AND uid_foreign=44
> 
> Notice that the last UPDATE will override what the first one did, so 
> that we end up with the MM-table containing:
> 
> 45, sorting = 2
> 44, sorting = 3
> 44, sorting = 3
> 
> and we would expect:
> 
> 44, sorting = 1
> 45, sorting = 2
> 44, sorting = 3
> 
> 
> Solution:
> In case of multiple=1, delete all records before we start and just write 
> the new ones in the order they come in (with INSERT). Attached patch 
> does that.
> 
> 
> Note:
> The problem is not present in TYPO3 4.2, because of this change done by 
> Kasper in January: http://code.typo3.org/v4/changeset/3002. The solution 
> here was to add a "uid" field for every MM table that needs 
> "multiple=1", to be able to identify each record uniquely even if they 
> contain the same uid_local/uid_foreign combination. I would like to fix 
> the bug in 4.1 like suggested above, because else we would have to 
> backport a new feature from 4.2 (new TCA setting "MM_hasUidField") to 4.1.
> 
> BTW that new feature (see Kasper's ChangeLog) hasn't been documented and 
> is not listed in 
> http://wiki.typo3.org/index.php/Pending_Documentation#doc_core_api. 
> Should I add it there?
> 
> Cheers,
> Ernesto
>