On 10/31/2011 07:55 PM, Markus Krötzsch wrote: > On 31/10/11 18:13, Samuel Lampa wrote: >> On 10/31/2011 06:52 PM, Samuel Lampa wrote: >>> === Q2: Status of SMWData/SMWDataItem as API? === >>> >>> Also I wondered what status the SMWData/SMWDataItem classes are supposed >>> to have, as a general API? ... Are they the supposed API, or is SMW >>> going towards preferring to talk SPARQL with all extensions ... or even >>> SMWExpElements? >>> >>> I ask this since it does not seem clear that I will really*need* to use >>> the SMWData/SMWDataItem combo as a representation, if I do the wiki page >>> updates either with the Wiki Object Model extension or an own writer >>> class. >>> >>> I would still prefer to use it, if it is pushed as a preferred API for >>> these kind of things, but I wondered whether that is so for the >>> foreseeable future? >> >> >> The thing that makes me wonder, is since we're basically talking about >> two slightly different (though very much overlapping) representations: >> RDF (as represented by SMWExpElement rel. classes), and Semantic >> MediaWiki facts (as repr. by SMWData/SMWDataItem). >> >> My problem, in the context of RDFIO, is that it seems I actually need >> both of these to capture the information from both worlds ... since: >> >> a. I need to store the URI:s, which only SMWExpElement classes do >> b. I need to store the wiki page titles that I choose to use (as part of >> RDFIO:s algorithm), which only the SMWData/SMWData combo does. >> >> ... thus it seems there's at least two options: >> >> 1. RDFIO creates an own more general data container, which wraps both >> the SMWData/SMWDataItem one, and the RDF one (possibly both the >> SMWExpElement one, and ARC2:s data structures), with in-built converters >> between all of these, >> >> 2. SMWData/SMWDataItem classes are updated to contain the "Original >> URI", and then this format will be the only needed one, in addition to >> possibly the ARC2 format, just for making use of it's parsers. >> >> >> Number one is the one I've been pondering so far ... I just wanted to >> point out this now and ask whether there would be any interest in >> storing also the original URI directly in the SMWData/SMWDataItem >> classes ... (which would not need to be required, for data that has no >> counterpart in the outside world, though ... or maybe can just be >> prefilled with the URIResolver URI:s ... this maybe on-the-fly, in a >> getter method)? >> >> ... it seems that would make the SMWData/SMWDI combo more general, and >> of course would make RDFIO add a lot less overhead :") >> >> (I know we discussed this on SMWCon already, but these things weren't >> really that clear to me then, about the partly but not completely >> overlap between RDF and SMW data representations ... so wanted to point >> it out ... ) > > I suggest to go for (1) if you need the full information in one object. > You should think of SMW data items as small and simple "values", similar > to an integer or a char in a programming language. They should be used > like constants of datatypes. They should only be used for storing data, > not for converting data or for augmenting it. They are pure data and > know nothing about HTML, wikitext or RDF. [Exception: the SMWDIContainer > type is a placeholder for compound data; it is not really considered as > an atomic value in SMW but just used for transporting compound data in > the API] > > With this view in mind, making an object that holds a URI and a dataitem > does not seem a bad idea (like making an object that holds an integer > and a string). > > Alternatively, you could of course represent URIs in an SMW data item as > well and relate them to wiki page with a property, stored together in an > SMWSemanticData.
Ok, many thanks for the feedback! The suggestions sounds reasonable - keeping in line with the modelling approach already taken. The only little caution I'd like to make, is that the decision keeping data objects atomic makes them follow the Anemic Model antipattern [1] a bit. But that is of course a question about model design approach overall, and not this specific case only - that is, whether one wants to follow Domain Driven Design patterns [2] or not. ... so for the moment I'm happy to follow the existing model design approach :) // Samuel [1] http://martinfowler.com/bliki/AnemicDomainModel.html [2] http://en.wikipedia.org/wiki/Domain-driven_design -- Samuel Lampa --------------------------------------- Bioinformatician @ Uppsala University Blog: http://saml.rilspace.org --------------------------------------- ------------------------------------------------------------------------------ Get your Android app more play: Bring it to the BlackBerry PlayBook in minutes. BlackBerry App World™ now supports Android™ Apps for the BlackBerry® PlayBook™. Discover just how easy and simple it is! http://p.sf.net/sfu/android-dev2dev _______________________________________________ Semediawiki-devel mailing list Semediawiki-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/semediawiki-devel
