[Nepomuk] Re: SimpleResource rcgen redesign draft

[Christian Mollekopf]

On Tue, 26 Jul 2011 09:52:20 +0200, Sebastian Trüg <trueg at kde.org> wrote:

> On 07/25/2011 11:17 PM, Christian Mollekopf wrote:
>> On Mon, 25 Jul 2011 23:09:26 +0200, Christian Mollekopf
>> <chrigi_1 at fastmail.fm> wrote:
>>
>>> Another thing I just noticed:
>>> The constructor should already set the type,
>>> in case no properties are set.
>>
>> Hmm... I guess it was done this way to avoid setting the myriad of types
>> in the hierarchy.
>
> exactly.
>
>> Maybe add an explicit setType function instead, or add it to the
>> resource() function,
>> if you go for the copy version.
>
> Hm, is it really necessary to have a type if nothing else is set? Why
> does one need the resource then anyway?
>

Because i.e. in the feeder I add only properties which don't actually  
belong to the most specific type.
(Things like the label, NCAL:location for incidences, etc)

Still all created items must have the right type, i.e. for queries with  
fulltext search.
And btw. think of the AkonadiDataObject type, where we don't even have a  
property to add for collections.

Cheers

>>>
>>> On Mon, 25 Jul 2011 21:20:45 +0200, Sebastian Trüg <trueg at kde.org>  
>>> wrote:
>>>
>>>> On 07/25/2011 07:52 PM, Christian Mollekopf wrote:
>>>>> On Mon, 25 Jul 2011 18:30:05 +0200, Sebastian Trüg <trueg at kde.org>
>>>>> wrote:
>>>>>
>>>>>> Now that the SimpleResource rcgen is in git master[1] some people  
>>>>>> used
>>>>>> it (mostly for Akonadi feeders and the web extractor framework) and
>>>>>> found it to be a bit strange.
>>>>>>
>>>>>> This is true. Current usage is as follows:
>>>>>>
>>>>>> SimpleResource r;
>>>>>> NCO::PersonContact(&r).setFullname("foobar");
>>>>>>
>>>>>> The reason for this is simple: due to multi-inheritance problems I
>>>>>> cannot derive the generated classes from SimpleResource. Thus, we  
>>>>>> need
>>>>>> wrappers.
>>>>>>
>>>>>> Now some ideas were floating around and I would like to settle on  
>>>>>> one
>>>>>> better solution.
>>>>>>
>>>>>> One idea would be to have a hybrid thing where you could do this:
>>>>>>
>>>>>>   NCO::PersonContact pc;
>>>>>>   pc.setFullname("foobar");
>>>>>>   SimpleResource r = rc.resource();
>>>>>>
>>>>>> and this:
>>>>>>
>>>>>>   SimpleResource r;
>>>>>>   NCO::PersonContact pc(r);
>>>>>>   pc.setFullname("foobar");
>>>>>>   r = pc.resource();
>>>>>>
>>>>>> (The last line would be required since all SimpleResources would be
>>>>>> copies.)
>>>>>
>>>>> Why can't you just take the reference to r, and the last copy  
>>>>> wouldn't
>>>>> be
>>>>> needed?
>>>>> Of course the accessor is still needed for the NCO::PersonContact pc;
>>>>> usecase.
>>>>
>>>> I cannot use refs for security reasons. Imagine someone returns a
>>>> generated class from a method after putting in a ref to a local
>>>> SimpleRes. Anyway, SimpleRes is implicitly shared.
>>>>
>>>>>>
>>>>>> We could go on like so:
>>>>>>
>>>>>>   r.addProperty(...);
>>>>>>   pc = r;
>>>>>>   pc.setResource(r);
>>>>>>
>>>>>> The only disadvantage I see here might be a slight performance
>>>>>> overhead
>>>>>> due to the copying of the resources.
>>>>>>
>>>>>> Opinions?
>>>>>
>>>>> Additionally it might be nice to have an accessor to the uri of the
>>>>> SimpleResource directly in the wrapper,
>>>>> and the << operator for the graph.
>>>>>
>>>>> So we would go from this:
>>>>>
>>>>>    Nepomuk::SimpleResource iconRes;
>>>>>    Nepomuk::NAO::FreeDesktopIcon icon(&iconRes);
>>>>>    icon.setIconNames( QStringList() << iconName );
>>>>>    graph << iconRes;
>>>>>    res.setProperty( Soprano::Vocabulary::NAO::prefSymbol(),
>>>>> iconRes.uri() );
>>>>>
>>>>> to this:
>>>>>
>>>>>    Nepomuk::NAO::FreeDesktopIcon icon;
>>>>>    icon.setIconNames( QStringList() << iconName );
>>>>>    graph << icon;
>>>>>    res.setProperty( Soprano::Vocabulary::NAO::prefSymbol(),  
>>>>> icon.uri()
>>>>> );
>>>>
>>>> nice.
>>>>
>>>> Cheers
>>>> Sebastian
>>>>
>>>>> Cheers,
>>>>>
>>>>> Christian
>>>>>
>>>>>>
>>>>>> Cheers,
>>>>>> Sebastian
>>>>>>
>>>>>> [1]
>>>>>> http://quickgit.kde.org/?p=kde-runtime.git&a=blob&h=304db56a9aff5523a5672415550c49d4b7269c3c&hb=344806a2e378f3421399cad39a63f14a4428308b&f=nepomuk/services/storage/lib/nepomuk-simpleresource-rcgen.py
>>>>>> _____________________________________________