Source code for publiforge.models.processors

"""SQLAlchemy-powered model definition for processors."""
# pylint: disable = super-on-old-class

from time import time
from os.path import join, dirname
from cStringIO import StringIO
from lxml import etree

from sqlalchemy import Column, types

from ..lib.xml import local_text, load_xml
from . import Base, DBSession, ID_LEN


# =============================================================================
class Processor(Base):
    """SQLAlchemy-powered processor model."""

    __tablename__ = 'processor'
    __table_args__ = {'mysql_engine': 'InnoDB'}

    processor_id = Column(types.String(ID_LEN), primary_key=True)
    xml = Column(types.Text())
    updated = Column(types.Float())

    # -------------------------------------------------------------------------
    def __init__(self, processor_id):
        """Constructor method."""
        super(Processor, self).__init__()
        self.processor_id = processor_id.strip()[0:ID_LEN]
        self.updated = time()

    # -------------------------------------------------------------------------
    @classmethod
    def load(cls, processor_id, xml):
        """Load a processor from a XML string.

        :param processor_id: (string)
            Processor ID.
        :param xml: (string)
            XML string.
        :return: (string, :class:`pyramid.i18n.TranslationString` or
            :class:`Processor`)
            Error message or processor object.
        """
        if isinstance(xml, unicode):
            xml = xml.encode('utf8')
        tree = load_xml('%s processor.xml' % processor_id, {
            'publiforge':
            join(dirname(__file__), '..', 'RelaxNG', 'publiforge.rng')}, xml)
        if isinstance(tree, basestring):
            return tree

        # Check if already exists
        processor = DBSession.query(cls).filter_by(
            processor_id=processor_id).first()
        if processor is None:
            processor = cls(processor_id)

        processor.xml = xml.decode('utf8')
        processor.updated = time()

        return processor

    # -------------------------------------------------------------------------
    @classmethod
    def ids(cls, request):
        """ID of all processors.

        :param request: (:class:`pyramid.request.Request` instance)
            Current request.
        :return: (list)
        """
        request.registry['fbuild'].refresh_agent_list(request)
        return [k[0] for k in DBSession.query(cls.processor_id).all()]

    # -------------------------------------------------------------------------
    @classmethod
    def labels(cls, request):
        """Label of all processors in local language or default language.

        :param request: (:class:`pyramid.request.Request` instance)
            Current request.
        :return: (dictionary)
            A dictionary such as ``{<processor_id>:
            <processor_label>,...}``.

        If some labels do not exist in the asked language, this method returns
        the label in default language or ``processor_id``.
        """
        request.registry['fbuild'].refresh_agent_list(request)
        labels = {}
        for processor in DBSession.query(cls.processor_id, cls.xml):
            tree = etree.parse(StringIO(processor[1].encode('utf8')))
            labels[processor[0]] = local_text(
                tree.find('processor'), 'label', request, default=processor[0])

        return labels

    # -------------------------------------------------------------------------
    @classmethod
    def description(cls, request, processor_id=None, xml=None):
        """Description of processor ``processor_id`` in local language or
        default language.

        :param request: (:class:`pyramid.request.Request` instance)
            Current request.
        :param processor_id: (string, optional)
            Processor ID.
        :param xml: (:class:`lxml.etree.ElementTree` instance, optional)
            Processor XML.
        :return: (string)
            Description.

        If some labels do not exist in the asked language, this method returns
        the label in default language or ``processor_id``.
        """
        if processor_id is not None:
            request.registry['fbuild'].refresh_agent_list(request)
            xml = DBSession.query(cls.xml).filter_by(
                processor_id=processor_id).first()
            if xml is not None:
                xml = etree.parse(StringIO(xml[0].encode('utf8')))
        if xml:
            return local_text(xml.find('processor'), 'description', request)
        return None