Source code for franz.openrdf.rio.rdfformat

################################################################################
# Copyright (c) 2006-2017 Franz Inc.  
# All rights reserved. This program and the accompanying materials are
# made available under the terms of the MIT License which accompanies
# this distribution, and is available at http://opensource.org/licenses/MIT
################################################################################

from __future__ import unicode_literals

from franz.openrdf.rio.formats import Format


class RDFFormat(Format):
    """
    Represents the concept of an RDF data serialization format. RDF formats are
    identified by a name and can have one or more associated
    MIME types, zero or more associated file extensions and can specify a
    default character encoding. Some formats are able to encode context
    information while others are not; this is indicated by the value of
    supports_contexts field. Similaraly, formats for which the
    supports_attributes flag is `True` are capable of encoding triple 
    attributes.
    """
    # A global dictionary mapping extensions to formats
    # Used by Format.format_for_file_name
    _ext_map = {}

    def __init__(self, name, mime_types=None, charset="UTF-8",
                 file_extensions=None, supports_namespaces=False,
                 supports_contexts=False, supports_attributes=False,
                 register=True):
        """
        Initialize a new RDF format object.

        :param name: Human-readable name of the format.
        :param mime_types: A list of MIME types used for this format.
                           The first element of this list will be used
                           as the content-type header during uploads.
        :param charset: Character set used by the format.
        :param file_extensions: List of file extensions for this format.
        :param supports_namespaces: If true, the format supports namespaces
                                    and qualified names. This has no impact
                                    on the Python API.
        :param supports_contexts: If True the format can store quads
                                  (and not just triples).
        :param supports_attributes: If True the format can represent triple
                                    attributes.
        :param register: If True file extensions will be added to the map
                         used by :meth:`Format.format_for_file_name`.
        """
        Format.__init__(self, name, mime_types, charset, file_extensions, register)
        self.supports_namespaces = supports_namespaces
        self.supports_contexts = supports_contexts
        self.supports_attributes = supports_attributes

    # These will be automatically converted to RDFFormat instances
        
    RDFXML = dict(
        name="RDF/XML",
        mime_types=["application/rdf+xml", "application/xml"],
        file_extensions=["rdf", "rdfs", "owl", "xml"],
        supports_namespaces=True, supports_contexts=False)

    NTRIPLES = dict(
        name="N-Triples",
        mime_types=["application/n-triples", "text/plain"],
        file_extensions=["nt", "ntriples"],
        supports_namespaces=False, supports_contexts=False)

    NQUADS = dict(
        name="N-Quads",
        mime_types=["application/n-quads"],
        file_extensions=["nq", "nquads"],
        supports_namespaces=False, supports_contexts=True)

    NQX = dict(
        name="Extended N-Quads (with attributes)",
        mime_types=["application/x-extended-nquads"],
        file_extensions=["nqx"],
        supports_namespaces=False, supports_contexts=True,
        supports_attributes=True)

    TURTLE = dict(
        name="Turtle",
        mime_types=["text/turtle"],
        file_extensions=["ttl", "turtle"],
        supports_namespaces=True,
        supports_contexts=False)

    TRIG = dict(
        name="TriG",
        mime_types=["application/trig"],
        file_extensions=["trig"],
        supports_namespaces=True,
        supports_contexts=True)

    TRIX = dict(
        name="TriX",
        mime_types=["application/trix"],
        file_extensions=["trix"],
        supports_namespaces=True,
        supports_contexts=True)

    TABLE = dict(
        name="Table",
        mime_types=["text/table"],
        file_extensions=[],
        supports_namespaces=False,
        supports_contexts=True)