Gluon

See the Oort website for specification and examples.

SparqlTree

An implementation of the SparqlTree mechanism for writing and digesting SPARQL queries into JSON.

A "SPARQL tree" is a processed SPARQL query result which combines bound variables into trees of data. It uses regular SPARQL queries with variables named according to a special convention.

RDFView

By subclassing oort.rdfview.RdfQuery and adding attributes which are instances of one of the Selector subclasses from that package, you define a set of rdf properties which are to be retrieved about a given subject (from a given graph, in a given language). The selectors are given a URIRef which determines the property. Or a Namespace, in which case the name of the attribute will be used.

These are some of the predefined classes from oort.util.queries:

class Typed(RdfQuery):
    rdfType = one(RDF.type)

class Labelled(RdfQuery):
    label = localized(RDFS)

class Annotated(Labelled):
    comment = localized(RDFS)

class Resource(Annotated, Typed):
    pass

Selectors can also be given RdfQuery types (or names of types, to enable e.g. cyclic references) which are used to describe their selected resources recursively. Use like this:

SIOC = Namespace("http://rdfs.org/sioc/ns#")

class Item(Annotated):
    _rdfbase_ = SIOC # sets default namespace base for this RdfQuery
    name = localized()
    description = localized()
    seeAlso = each(RDFS) >> Annotated

The overloaded >> is just sugar for:

seeAlso = each(RDFS).viewed_as(Annotated)

Predefined selectors in oort.rdfview are: one, each, one_where_self_is, each_where_self_is, collection, localized, i18n_dict, each_localized and localized_xml.

RdfQueries are either directly instantiated with an RDFLib Graph instance, language (string) and URIRef instance, or used via QueryContext, which facilitates this and other things.