Source code for surf.plugin

# Copyright (c) 2009, Digital Enterprise Research Institute (DERI),
# NUI Galway
# All rights reserved.

# author: Cosmin Basca
# email: cosmin.basca@gmail.com

# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#    * Redistributions of source code must retain the above copyright
#      notice, this list of conditions and the following disclaimer.
#    * Redistributions in binary form must reproduce the above copyright
#      notice, this list of conditions and the following disclaimer
#      in the documentation and/or other materials provided with
#      the distribution.
#    * Neither the name of DERI nor the
#      names of its contributors may be used to endorse or promote
#      products derived from this software without specific prior
#      written permission.

# THIS SOFTWARE IS PROVIDED BY DERI ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DERI BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
# OF THE POSSIBILITY OF SUCH DAMAGE.

# -*- coding: utf-8 -*-
from abc import ABCMeta
import logging

__author__ = 'Cosmin Basca'


class Plugin(object):
    """
    Super class for all SuRF plugins, provides basic instantiation and `logging`.
    """

    __metaclass__ = ABCMeta

    def __init__(self, *args, **kwargs):
        super(Plugin, self).__init__()
        self._inference = False

    def close(self):
        """
        Close the `plugin` and free any resources it may hold
        """

    @property
    def inference(self):
        """
        Toggle `logical inference` on / off. The property has any effect only if such functionality is supported by
        the underlying  :class:`surf.store.Store` store
        """
        return self._inference

    @inference.setter
    def inference(self, val):
        if not isinstance(val, bool):
            val = False
        self._inference = val