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June 30th, 2003, by Rich, in RDFX.
Although not immediately apparent, the usefulness of the list view is large. In a nutshell, the concept of the list view is that it provides a flat list of all Resources thus:
To list is very basic, so perhaps the resource type could be included in a table rather than a list view. Filters could be added based on Type, Source, Content etc… the important thing is that it provides a neat way of displaying all the data model so that, upon a double click (possibly) the RDF Explorer root can be set - perhaps in an existing view, perhaps in a new view - this could be set in the prefs.
Such niceties are for further down the line anyway - for now, the mechanism is just that when a node is clicked, it is selected in an existing RDF explorer if it exists, and when double-clicked the explorer tree root is set to the chosen node.
June 25th, 2003, by Rich, in RDFX.
in building RDFSchemaLabelProvider i’ve had some interesting namespace problems. some namespaces are defined, ending with a “#”, which include the name of the definition file, some have no hash, no trailing slash, and define a URL where that file can be assumed to be, for example:
[xml]
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:foaf="http://xmlns.com/foaf/0.1">
[/xml]
This is a pain when trying to work out (a) which file to load and then (b) what the actual namespace should be for the content of that file - in the case of the rdf namespace the file is exactly as described - http://www.w3.org/1999/02/22-rdf-syntax-ns but in the case of foaf namespace the file is http://xmlns.com/foaf/0.1/index.rdf
:-?
June 25th, 2003, by Rich, in RDFX.
RDF contains some structures. Bag and Set, for example - then - extensions to the schema can also contain structures - DAM+OIL and OWL for example add concepts of cardinality - should the browser be able to handle these specially, or just treat them as resources (which they are).
Essentially - is there a need for a mechanism which interprets the resource type and substitutes a replacement, bespoke INode implementation, and if there is that need, can it be done? Answers: No, not for UISB and Yes, but it might prove interesting :)
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.
