Source code for sylib.calculator.plugins

# -*- coding:utf-8 -*-
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from sympathy.utils.components import get_components


class ICalcPlugin(object):
    """Interface for calculator plugins."""

    WEIGHT = 10000

    @staticmethod
    def gui_dict(generic):
        """
        Return a dictionary with functions that will be shown in the
        configuration gui for the calculator node.
        """
        return {}

    @staticmethod
    def globals_dict():
        """
        Return a dictionary that will be added to the globals dictionary
        when executing calculations.
        """
        return {}

    @staticmethod
    def imports():
        """
        Return a dictionary with extra imports that will be available in
        the calculator.
        For example, add the imports::

            import math
            import scipy.integrate
            import scipy.signal as sig

        to your plugin, and return a dictionary like this::

            return {'math': math,
                    'spint': scipy.integrate,
                    'sig': sig}

        and math, spint and sig will be available as modules in the calculator.
        """
        return {}

    @staticmethod
    def signals_dict():
        """
        Define signals that are needed to run the functions as written in
        eval texts, when running the tests.
        Must have the same length.
        """
        return {}

    @staticmethod
    def variables_dict():
        """
        Define variables that are needed to run the functions as written in
        eval texts, when running the tests.
        """
        return {}


class MatlabCalcPlugin(object):
    """Interface for calculator plugins."""

    WEIGHT = 10000

    @staticmethod
    def gui_dict(generic):
        """
        Return a dictionary with functions that will be shown in the
        configuration gui for the calculator node.
        """
        return {}

    @staticmethod
    def globals_dict():
        """
        Return a dictionary that will be added to the globals dictionary
        when executing calculations.
        """
        return {}


def available_plugins(backend='python'):
    """Return all available plugins derived for a specific backend."""
    plugin_classes = {'python': ICalcPlugin,
                      'matlab': MatlabCalcPlugin}
    return get_components('plugin_*.py', plugin_classes[backend])


class PluginWrapper(object):
    """
    Merge two or more module-like objects into one.

    getattr calls on PluginWrapper objects are passed on to the module-like
    objects and the first one which doesn't raise AttributeError gets to return
    its result.
    """

    def __init__(self, *namespaces):
        self._namespaces = list(namespaces)

    def __getattr__(self, attr):
        for ns in self._namespaces:
            try:
                return getattr(ns, attr)
            except AttributeError:
                pass

        raise AttributeError(attr)