I am new to all this and trying to build a simple example application. I want to arrange for my PC to display a special message-of-the-day banner on login if there are any pending "change freezes" for this system. To do this it will query the triplestore using LDPath to find the change freeze events that are associated with the machine as identified by its fqdn (in this case "pug.local").
I have marmotta set up and created two containers using LDP: one for Systems, including my PC, the other for change freeze events. Here are some examples: A "System"... @prefix ldp: <http://www.w3.org/ns/ldp#> . @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix xsd: <http://www.w3.org/2001/XMLSchema#> . @prefix dcterms: <http://purl.org/dc/terms/> . @prefix parent: <http://192.168.0.11:8080/marmotta/ldp/Systems/> . @prefix child: <http://192.168.0.11:8080/marmotta/ldp/Systems/Pug-2/> . @prefix this: <http://192.168.0.11:8080/marmotta/ldp/Systems/Pug-2#> . parent:Pug-2 a ldp:Resource , ldp:RDFSource , ldp:Container , ldp:BasicContainer ; ldp:interactionModel ldp:Container ; dcterms:created "2015-07-21T22:36:30.000-07:00"^^xsd:dateTime ; dcterms:modified "2015-07-21T22:36:30.000-07:00"^^xsd:dateTime ; a <http://open-services.net/ns/crtv#ComputerSystem> ; <http://open-services.net/ns/crtv#fqdn> "pug.local" ; <http://open-services.net/ns/crtv#ipAddress> "192.168.0.11" . Some "Freezes" parent:8 a ldp:Resource , ldp:RDFSource , ldp:Container , ldp:BasicContainer ; ldp:interactionModel ldp:Container ; dcterms:created "2015-07-21T23:45:13.000-07:00"^^xsd:dateTime ; dcterms:modified "2015-07-21T23:45:13.000-07:00"^^xsd:dateTime ; a <http://www.w3.org/2002/12/cal/icaltzd#Vevent> ; <http://www.w3.org/2002/12/cal/icaltzd#class> "Freeze" ; rdf:about <http://192.168.0.11:8080/marmotta/ldp/Systems/Pug-2> ; <http://www.w3.org/2002/12/cal/icaltzd#dtstart> "2015-07-28T20:00:00"^^<http://www.w3.org/2002/12/cal/tzd/America/Boise#tz> ; <http://www.w3.org/2002/12/cal/icaltzd#dtend> "2015-07-29T23:00:00"^^<http://www.w3.org/2002/12/cal/tzd/America/Boise#tz> . And... parent:9m a ldp:Resource , ldp:RDFSource , ldp:Container , ldp:BasicContainer ; ldp:interactionModel ldp:Container ; dcterms:created "2015-07-21T23:43:47.000-07:00"^^xsd:dateTime ; dcterms:modified "2015-07-21T23:43:47.000-07:00"^^xsd:dateTime ; a <http://www.w3.org/2002/12/cal/icaltzd#Vevent> ; <http://www.w3.org/2002/12/cal/icaltzd#class> "Freeze" ; rdf:about <http://192.168.0.11:8080/marmotta/ldp/Systems/Pug-2> ; <http://www.w3.org/2002/12/cal/icaltzd#dtstart> "2015-07-25T23:00:00"^^<http://www.w3.org/2002/12/cal/tzd/America/Boise#tz> ; <http://www.w3.org/2002/12/cal/icaltzd#dtend> "2015-07-26T23:00:00"^^<http://www.w3.org/2002/12/cal/tzd/America/Boise#tz> . All of these are separate resources (ie, they are not all in the same rdf file) though per default they are set up as separate LDPCs (I'm not sure if that matters). I would like to make a single LDPath query that will return a list of all "Freezes" for a PC with a given fqdn. My attempts at a queries have varied over the last few hours, but in general look like... alanr@pug:~/apache-marmotta-tutorial-iswc2014/ldp$ curl -iX POST --data ' @prefix ldp: <http://www.w3.org/ns/ldp#> ; @prefix sys: <http://192.168.0.11:8080/marmotta/ldp/Systems/> ; @prefix crtv: <http://open-services.net/ns/crtv#> ; @prefix cal: <http://www.w3.org/2002/12/cal/icaltzd#> ; about=ldp:contains/rdf:about[crtv:fqdn is "pug.local"] ; start=ldp:contains[rdf:about is sys:Pug-2]/(cal:dtstart) ;' -H 'Content-Type: text/plain' http://192.168.0.11:8080/marmotta/ldpath/program?uri=http://192.168.0.11:8080/marmotta/ldp/Freezes And the result I get is... {"start":[{"value":"2015-07-21T23:00:00","datatype":"http://www.w3.org/2002/12/cal/tzd/America/Boise#tz","type":"literal"},{"value":"2015-07-25T23:00:00","datatype":"http://www.w3.org/2002/12/cal/tzd/America/Boise#tz","type":"literal"},{"value":"2015-07-28T20:00:00","datatype":"http://www.w3.org/2002/12/cal/tzd/America/Boise#tz","type":"literal"}],"about":[{"value":"http://192.168.0.11:8080/marmotta/ldp/Systems/Pug-3","type":"uri"},{"value":"http://192.168.0.11:8080/marmotta/ldp/Systems/Pug-2","type":"uri"}]} I'd like a single query to return all the freezes for a system specified by its fqdn in one shot (ie. if possible not have to query to collect the resources with that fqdn (eg sys:Pug-2) followed by a separate query to get the freezes that are rdf:about sys:Pug-2) I have two questions... 1) How can I select cal:dtstart and cal:dtend times for freezes belonging to the freeze matching rdf:about[crtv:fqdn is "pug.local"] ? I can see how I can select rdf:about, but not the other fields in the freeze record 2) How can I group the results together ? If I mess with it I can get a list of start times, a list of end times or even a big list of start and end times mixed together, but I can't figure a way to get a list of pairs of start and end times that go together, one for each "Freeze". Maybe I have just structured the data wrongly. Thanks for your consideration Alan
