Re: Using RDF queries with beagle
Enrico Minack <[email protected]>
| Newsgroups | gmane.comp.gnome.dashboard.devel |
|---|---|
| Organization | L3S |
| Message-ID | <1203197477.6229.62.camel@vmware-ubuntu> |
> > @dBera: I would suggest to modify the RDFQuery so that it only takes > > subject, predicate and object, where the predicate is the one dumped by > > beagle-dump-index --fields. The property type can then be derived from > > the property name. I know that this exposes the internal property name > > like > > prop:k:beagle:MimeType > > but since users of the RDFQuery have to specify Text, Keyword or > > Internal anyways, they can take the long property name in the first > > place. This makes things easier. > > Go for it. attached you find a patch that removes the predicate type from the RDFQuery. > This might need some change in the LuceneQueryingDriver > code; if you get lost there, let me know. I guess you mean to get prop:k:beagle:MimeType instead of beagle:MimeType out of the RDF query, since I put the long form in the query. Well, maybe the Property class gets an 'fullKey' attribute, which is set by the respective backend to the internal / long value. The LuceneBackend would set this using the PropertyToFieldName method. But other backends would need to do it differently. Well, the RDFQuery already does LuceneBackend magic (removing prop:k:), so I don't know what is right here. Enrico M. _______________________________________________ Dashboard-hackers mailing list [email protected] http://mail.gnome.org/mailman/listinfo/dashboard-hackers
beagle-rdf.diff
(text/x-patch, 3.8 KB)
Index: BeagleClient/Query.cs
===================================================================
--- BeagleClient/Query.cs (Revision 4490)
+++ BeagleClient/Query.cs (Arbeitskopie)
@@ -283,13 +283,29 @@
Keepalive = false;
}
- public RDFQuery (Uri subject, string predicate, PropertyType predicate_type, string _object) : this ()
+ public RDFQuery (Uri subject, string predicate, string _object) : this ()
{
+ // extract the property type from the property, and remove the prop:?: prefix
+ // e.g. from prop:k:beagle:MimeType
+ PropertyType ptype = PropertyType.Internal;
+
+ if (predicate != null) {
+ if ((predicate.Length > 7) && predicate.StartsWith ("prop:")) {
+ switch (predicate [5]) {
+ case 't': ptype = PropertyType.Text; break;
+ case 'k': ptype = PropertyType.Keyword; break;
+ case 'd': ptype = PropertyType.Date; break;
+ }
+ // remove the prop:?:, which will be added by beagle later
+ predicate = predicate.Substring (7);
+ }
+ }
+
this.Subject = subject;
this.Predicate = (predicate == null ? String.Empty : predicate);
- this.PredicateType = predicate_type;
+ this.PredicateType = ptype;
this.Object = (_object == null ? String.Empty : _object);
-
+
// FIXME: the query contains a dummy part that will make the query
// pass even if it is empty. Empty queries are not handled by default.
//
Index: RDFAdapter/BeagleSource.cs
===================================================================
--- RDFAdapter/BeagleSource.cs (Revision 4490)
+++ RDFAdapter/BeagleSource.cs (Arbeitskopie)
@@ -76,23 +76,7 @@
}
}
- // extract the property type from the property
- // e.g. from prop:k:beagle:MimeType
- PropertyType ptype = PropertyType.Internal;
-
- if (p != null) {
- if ((p.Length > 7) && p.StartsWith ("prop:")) {
- switch (p [5]) {
- case 't': ptype = PropertyType.Text; break;
- case 'k': ptype = PropertyType.Keyword; break;
- case 'd': ptype = PropertyType.Date; break;
- }
- // remove the prop:?:, which will be added by beagle later
- p = p.Substring (7);
- }
- }
-
- RDFQuery query = new RDFQuery (s, p, ptype, o);
+ RDFQuery query = new RDFQuery (s, p, o);
RDFQueryResult result = (RDFQueryResult) query.Send ();
foreach (Hit hit in result.Hits) {
Index: tools/RdfQueryTool.cs
===================================================================
--- tools/RdfQueryTool.cs (Revision 4490)
+++ tools/RdfQueryTool.cs (Arbeitskopie)
@@ -8,11 +8,10 @@
public static void Main (string[] args)
{
- if (args.Length != 4) {
+ if (args.Length != 3) {
Console.WriteLine ("Usage: program-name <subject> <predicate> <predicate-type> <object>");
Console.WriteLine (" <subject> : URI or path");
Console.WriteLine (" <predicate> : property name (string)");
- Console.WriteLine (" <predicate-type> : property type (Internal,Text,Keyword,Date)");
Console.WriteLine (" <object> : object (string)");
Console.WriteLine (" Use \"\" (empty string) for unspecified subject, predicate, type or object");
return;
@@ -20,17 +19,13 @@
RDFQueryResult result;
- Console.WriteLine ("subject:'{0}' predicate:'{1}'({3}) object:'{2}'", args [0], args [1], args [3], args [2]);
+ Console.WriteLine ("subject:'{0}' predicate:'{1}' object:'{2}'", args [0], args [1], args [2]);
Uri subject = null;
if (args [0] != String.Empty)
subject = new Uri (args [0]);
- PropertyType type = PropertyType.Text;
- if (args [2] != String.Empty)
- type = (PropertyType) Enum.Parse (typeof (PropertyType), args [2], true);
-
- RDFQuery query = new RDFQuery (subject, args [1], type, args [3]);
+ RDFQuery query = new RDFQuery (subject, args [1], args [2]);
result = (RDFQueryResult) query.Send ();
if (result == null) {