[Nepomuk] Re: SimpleResource rcgen redesign draft

[Sebastian Trüg]

On 07/26/2011 10:06 AM, Christian Mollekopf wrote:
> 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.

I suppose I could add a protected constructor to all classes which would
be used by child classes. This constructor would take a type URI as
input. That way only the top-level type would be set.

Cheers,
Sebastian

> 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
>>>>>>> _____________________________________________
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