For various reasons I needed to look at SPARQL again. What’s the easiest way to put it up?, Here! I’ve been working with LH-Tools which is commented on at its authors site, and LH-RDF. I did not get this to finish satisfactorily, mainly based on my lack of SPARQL skills. May 2015 I returned to this page sporadically. Here are my notes …
LH-Tools implements a SPARQL endpoint, and LH-RDF implements a series of alternative RDF schemas. LH-RDF has been deactivated at the moment, and so I no longer have the SPARQL query screen available.
Pool Party are now playing. i,e. there’s a Pool Party plugin.
I have errors occurring when using LH-RDF; see the comments to track. Jan 2017
Queries
I think that, http://${SITENAME}/feed/rdf offers rdf based on standard wordpress functionality, although it seems to have a limited number of entries. LH Tools via its settings panel can use this as the query target. This seems to be working. The settings panel has been used to point the query screen at the default feed URL.
HTML Headers
These applications and wordpress do not write the HTML <link> record. I need to check if this is still true. (How to best insert the code into header.php, or do I have to get inside the plugin code?) May 2015. I don’t understand this, the documentation for LH-RDF claims it does, but it’s otherwise broken at the moment. Jan 2017.
LH-RDF
There is a readme file in the LH-RDF plugins directory, by re-saving the permalinks options the pretty rdf name becomes visible.
- https://davelevy.info/wiki/feed/lhrdf
- https://davelevy.info/wiki/?feed=lhrdf&lhrdf=json, the json and sioc feeds gnerate errors.
However in the summer of 2015, the LH RDF panel needed “post-to-posts” plugin which is no longer supported by it’s original author. Also when installed php error’s occurred and were displayed on the panel page and the feed pages.
SPARQL
An example tutorial
And there’s much more, I was looking for a course,
Some Links
- The Endpoint i.e. Query Screen on this blog/wiki.
- https://davelevy.info/wiki/feed/rdf/, the default RDF feed on this blog/wiki
- The lh tools plugin i.e the endpoint at the wordpress codex
- The RDF feed generator (LH RDF) plugin at the wordpress codex
- The author’s comments on LH-TOOLs
- A commentary on LD RDF on lhero.org
and Pool Party plugin
and the ticket requests
I used a plugin LH RDF to render the feed into RDF. This became incompatible with the wordpress rewrite module on 21/8/2015 when I updated the module. I have deactivated the plugin.
LH RDF broke this a.m. i.e. 21 August 2015, when I upgraded some stuff. A further upgrade was issued that fixed the destructive behaviour. It was fixed within 24 hours.
I have discovered further problems with these tools. It writes error rdf. I have reported it here, on the wordpress codex site.
The LH RDF readme says, “If you wish to map additional relationships install the Posts 2 Posts add some connections then map them to rdf by going to Settings LH RDF->Mappings”. I have no idea what does add some connections mean? Has the author made some assumptions when mapping the WP Schema to an RDF object map, and this is a way of adding RDF relationships; the settings screen doesn’t make it seem so.
This comment was made in Jan 2017, to preserve content originally created in 2015.
This ought to be simpler, I documented a google query I used when looking for a course on SPARQL.
I changed the featured image, and looked around my living room to check if I had the O’Reilly book which is in my amazon wish list, but if I pick this up again, I think I need to start somewhere else.