mORMot Open Source

sgavrilov

Member

Registered: 2019-05-24

Posts: 20

TClassNameToBeDeletedID does not work

Hello,

Environment: Delphi XE2, TRestServerDB, SQLite3 database, 4 tables in a model, one of the tables references another by a TClassNameToBeDeletedID field.

It appears that the TClassNameToBeDeletedID does not work as expected: the field index is not created and (I suspect) the cascade deletion does not work either.

I have found the immediate cause for this in the unit mormot.orm.core but deeper details elude me.

constructor TOrmPropInfoRttiTID.Create(aPropInfo: PRttiProp; aPropIndex: integer; aOrmFieldType: TOrmFieldType; aOptions: TOrmPropInfoListOptions);
...

  if IdemPropName(TypeName^, 'TID') or
     (ord(TypeName^[1]) and $df <> ord('T')) or // expect T...ID pattern
     (PWord(@TypeName^[L - 1])^ and $dfdf <> ord('I') + ord('D') shl 8) or
     (Rtti.Counts[rkClass] = 0) then
    exit;
  if (L > 13) and IdemPropName('ToBeDeletedID', @TypeName^[L - 12], 13) then
  begin   // 'TOrmClientToBeDeletedID' -> TOrmClient + CascadeDelete=true
    fCascadeDelete := true;
    Found := Rtti.FindName(@TypeName^[1], L - 13, rkClass);
  end
...
end;

The condition (Rtti.Counts[rkClass] = 0) is False. If it is commented out then the code works as expected.

Best regards,
Sergey

sgavrilov

Member

Registered: 2019-05-24

Posts: 20

Re: TClassNameToBeDeletedID does not work

It appears that I have found the problem: it is in the unit mormot.core.rtti.

It seems to me that instead of

inc(Counts[Instance.Kind]);

the following code should be used in the procedure TRttiCustomList.AddToPairs(Instance: TRttiCustom; Info: PRttiInfo):

inc(Counts[Info.Kind]);

When the AddToPairs is called from the function TRttiCustomList.DoRegister

    // initialize a new TRttiCustom/TRttiJson instance for this type
    result := GlobalClass.Create;
    // register ASAP to avoid endless recursion in FromRtti
    AddToPairs(result, Info);
    // now we can parse and process the RTTI
    result.FromRtti(Info);

the first parameter (result) is not completely initialized yet and the Instance.Kind always equals to rkUnknown inside the AddToPairs. Therefore, the correct counters in the array are not incremented.

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,242

Website

Re: TClassNameToBeDeletedID does not work

You are right!

Please try with https://github.com/synopse/mORMot2/commit/306a0cfa

sgavrilov

Member

Registered: 2019-05-24

Posts: 20

Re: TClassNameToBeDeletedID does not work

Thank you!