Oort A toolkit for accessing RDF graphs as plain objects. ======================================================================== Oort ======================================================================== Oort is a a Python_-based toolkit for accessing RDF_ graphs as plain objects. It uses RDFLib_ for the heavy lifting. .. _RDF: http://www.rdfabout.net .. _Python: http://python.org .. _RDFLib: http://rdflib.net Overview ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``oort.rdfview`` Contains classes and functions used for defining RDF queries and selectors, i.e. declarations used to pick properties and associated sub-queries from a chosen resource (similar to how many ORM-toolkits work). ``oort.util.queries`` Some basic base ``RdfQuery`` subtypes for common use (e.g. getting at localized annotation properties such as ``rdfs:label`` and similar). ``oort.util.graphs`` A collection of basic "filesystem-to-graph" utilities. How? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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. Se more examples (and test source code) at the `Oort Website`_. .. _`Oort Website`: http://oort.to The latest development version can be installed from the `Oort SVN Trunk <http://oort.googlecode.com/svn/Oort/trunk#egg=Oort-dev>`_. Niklas Lindström 286e3265015ee90e52055842fc78ce6102846727 0.4