wikipedia-transifex

# -*- coding: utf-8 -*-

"""

Module to abstract the mapping of languages used locally versus the language

codes used in Transifex.

"""

class Language(object):

    """A language class.

    It supports defining a Trasnifex and a local language code.

    """

    def __init__(self, tx_code, local_code=None):

        """Initializer.

        Initialize the Tx and local codes. If no local_code is defined, we

        set it to tx_code.

        Args:

            tx_code: The language code as used by Transifex.

            local_code: The language code as used locally.

        """

        self._tx_code = tx_code

        if local_code is not None:

            self._local_code = local_code

        else:

            self._local_code = self._tx_code

    @property

    def local_code(self):

        return self._local_code

    @property

    def tx_code(self):

        return self._tx_code

    def __unicode__(self):

        return u"<Language: %s-%s>" % (self._tx_code, self._local_code)

    def __str__(self):

        return self.__unicode__().encode('UTF-8')

class LanguageContainer(object):

    """A container for Language objects."""

    def __init__(self):

        """Initializer."""

        self._tx = {}

        self._local = {}

    def add(self, lang):

        """Add a language to the collection.

        It will not add it, if the langauge exists already.

        Args:

            lang: The Language object to add.

        Raises:

            ValueError, if the language already exists in the collection.

        """

        self._insert_lang(lang, overwrite=False)

    def insert(self, lang):

        """Insert a language to the collection.

        This operation will override existing languages.

        Args:

            lang: The Language object to add.

        """

        self._insert_lang(lang, overwrite=True)

    def _insert_lang(self, lang, overwrite):

        """Insert a language to the collection.

        If overwrite is True, the overwrite any existing langauage. Else, raise

        a ValueError.

        Args:

            lang: The Language object to add.

            overwrite: A boolean flag, indicating whether to override existing

                values or raise an exception.

        Raises:

            ValueError, if overwrite is False and the lang object exists.

        """

        tx_key = lang.tx_code

        local_key = lang.local_code

        error_msg = "Language %s already exists."

        if tx_key in self._tx:

            if overwrite:

                old_lang = self._tx[tx_key]

                self.remove(old_lang)

            else:

                raise ValueError(error_msg % lang)

        if local_key in self._local:

            if overwrite:

                old_lang = self._local[local_key]

                self.remove(old_lang)

            else:

                raise ValueError(error_msg % lang)

        self._tx[tx_key] = lang

        self._local[local_key] = lang

    def remove(self, lang):

        """Remove a language from the collection.

        The method guarantees that the collection will always be at a

        consistent state.

        Args:

            lang: A Language object to remove.

        Raises:

            ValueError, if lang is not in the collection.

        """

        if lang.tx_code not in self._tx or lang.local_code not in self._local:

            raise ValueError("Language does not exist: %s." % lang)

        del self._tx[lang.tx_code]

        del self._local[lang.local_code]

    def __contains__(self, item):

        """Support the in operator.

        Args:

            item: A language object.

        Returns:

            True, if the language exists. False, otherwise.

        """

        return item.tx_code in self._tx or item.local_code in self._local

    def __len__(self):

        """Support the len function on the container."""

        assert len(self._tx) == len(self._local)

        return len(self._tx)

def iter_tx_codes(lang_container):

    """Iterator to iterate over the language codes as used in Transifex.

    Args:

        lang_container: The LanguageContainer object to iterate over.

    """

    for key in lang_container._tx.iterkeys():

        yield key

def iter_local_codes(lang_container):

    """Iterator to iterate over the language codes as used locally.

    Args:

        lang_container: The LanguageContainer object to iterate over.

    """

    for key in lang_container._local.iterkeys():

        yield key