Semantic Computing: the extension of the Semantic Web to the point where its methods and standards are pervasive in all computing. If you don’t believe this will happen, you might as well go the whole hog and say that the wheel will never catch on.
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June 25th, 2003, by Rich, in RDFX.
the idea of dynamic schema validation got me thinking about adaptive resource representation in the UI. It coudl be quite effectively handled with decorators, so the concept could work for more than just schema - it could be extended to information which is owned vs borrowed, trusted vs un-trusted, fresh vs stale vs expired etc…
June 25th, 2003, by Rich, in RDFX.
Although not all schemas are accessible, many are; which is good news. What’s even better is the existence of “rdfs:label” which “Provides a human-readable version of a resource name.”
So now any unknown label should be retrievable by going to the URI specified in the NS, downloading the RDF Schema document, pulling out the appropriate resource and getting the label property.
If it’s that simple, then programming with RDF is frankly more orgasmic than a nice cup of tea and a biscuit.
Note: when auto loading rdf schema the HTTP method of looking for index.rdf may be utilised if no document is specified - this, for example is used by FOAF.
OK, so where are they stuck? It’s perfectly feasible to load the schema into the main RDF store for now, but a concept i’ve not discussed here yet is the separation of the RDF store to a separate plugin whose role it is to supply RDF services - this plugin can then be a front for (a) other RDF services and (b) provide transient or permanent RDF stores.
Well, a couple of hours later and it’s working.
When a label is required the RDFSchemaLabelProvider does the job of checking for it, and if possible, loading it. Currently I’m using a separate jena Model to store the namespaces. Also, there’s some strange behaviour with namespace naming oddness, where some namespaces are not exactly what they seem, this may be down to conten negotiation but there are no RFC’s for that yet…
One last thing: “label” is not always used - there’s likely to be usage of “name” and “title” - perhaps some search order preference should be configurable - just not by me, and not right now, this is good enough - however - assuming there were a few preferred content elements, one of those could be substituted for the URI in the Query Tree… or maybe not since each Query should/could have a name - in which case this becomes a good argument for having an RDF Explorer and an RDF exploder. Ah - but then again - a Query node could be treated differently.. it’s very late, i’m sorry :)
June 25th, 2003, by Rich, in Eclipse, RDFX.
Some good news. I now have an RDFX View linked to the properties view so that both Resources and Literals are showing up.
Still to do however:
1. Stop showing the triple, just show the RDF object value
2. Display resources and Literals in different twisties within the Properties View (and add user preference)
3. You may also notice that the content of the RDFX View tree has been frigged - this is currently a big to do.
4. Also, for twisties, are cases where there are multiple values for a particular property.
5. Add a lookup for the Property Name so that if it has a “plain english” value defined somewhere it can be used - (using schemas notes added on this later).
June 25th, 2003, by Rich, in RDFX.
In order to get an RDF Resource displayed in the Properties view it needs to be accessible through an object which implements the IPropertySource interface. My first pass saw me configure my INode interface to extends IPropertySource, however, noting that INode is merely a container for a Resource, not the resource itself, and that several INode’s may point to a single Resource this may not be the best solution - time will tell - i’m sticking with the first idea for expedience.
Time passes…
OK, so scratch that - having read some more I’m getting convinced that’s what’s needed is to take the [official] alternative path to implementing IPropertySource which is to implement IAdaptable. An object which does this will return an adapter object when requested - this adapter object contains the code used by the Properties view, and queries the underlying object for the information required.
This, I think will give me a nice abstraction so I can use different RDF API’s (should an alternative to Jena be required).
June 19th, 2003, by Rich, in RDFX.
perhaps a schema for linking icons to node types - should be slightly indirected such that (a) there can be an officially sanctioned representation (b) there can be themed alternate representations and (c) it’s not limited to bitmaps - an SVG based icon, for example, would be most welcome - even if eclipse can’t display it, it would only be a requirement of having a conversion program included - i.e. not a big problem.
June 19th, 2003, by Rich, in RDFX.
XUL looks very interesting - i’ve taken the time to download LUXOR a few days back, but it’s just too much extra technology to get on my brain-radar at the moment. Briefly, XUL the XML UI Language, could enable me to build a single interface, defined in XML for any platform - however - the libraries don’t appear too mature - it’s perhaps something for version x.y.z.
June 19th, 2003, by Rich, in RDFX.
The current use of icons is not brilliant - it needs to be defined such that for any UI widget there is the ability to choose an icon. However, it’s really down to the schema rather than the UI - sounds another job for our retrospectively linked hero RDF, and some kind of indirection mechanism.
June 19th, 2003, by Rich, in RDFX.
I’m a little confused right now WRT where exactly the RDFX core should be started - it’s either in the RDFXView class or in the plugin class - i’m assuming it’s in the plugin class… but… because everything’s event based there’s a risk of the core being ready before the view - and the view missing out on the initial broadcasts - what this means therefore is that there may need to be some kind of regular (i.e. once every n seconds) broadcast from the core to allow interested views to come and go whilst the core remains. This is very similar to the Jini lookup model - and so I’m immediately thinking that there is potential for a two way event with a View announcing it’s arrival and requesting the transmission of a “top node” from the model.
Time passes… Yes, it’s the plugin that should start the RDFX core and then when a view is started it will announce that it would like to know about “any node which can be a top node” or announce that it wants to know about node x” - where x is a URI - this then allows for multiple views and for the user to define the top node URI, should that prove useful - a kind of “start exploring from…” function.
June 19th, 2003, by Rich, in RDFX.
I just noticed that RDFX.org (and just about everything else bar .com is free, so I grabbed .org for the open-source friendly advertising that we want for this. it’ll redirect to the uni’s hosted pages, but it makes it very easy for folk to remember.
June 19th, 2003, by Rich, in RDFX.
In RDF, two resources with the same URI are considered to be the same Node. In an RDFX View this may not the case. Due to the cyclic nature of graphs it is necessary to have repeat entries for certain nodes in order that the graph model be rendered as a navigable tree.
