models.py

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

# "Future imports"
from __future__ import unicode_literals

# "Standard libs"
import sys
from warnings import warn

# "Django imports"
from django.core.urlresolvers import reverse
from django.db import models
from django.utils import six
from django.utils.encoding import python_2_unicode_compatible
from django.utils.functional import lazy
from django.utils.safestring import mark_safe
from django.utils.timezone import now
from django.utils.translation import ugettext_lazy as _

mark_safe_lazy = lazy(mark_safe, six.text_type)
newsbox_models = []


def newsbox_mcls_processor(mcls, class_name, class_bases, class_attrs, base, newsbox_opts):
    if 'newsbox_title' not in class_attrs:
        class_attrs['newsbox_title'] = models.CharField(
            verbose_name=_('title'),
            help_text=_('The title should not be too long and should be explicit'),
            max_length=255)
        newsbox_opts['trans_fieldnames'].append('newsbox_title')
    if 'newsbox_slug' not in class_attrs:
        class_attrs['newsbox_slug'] = models.SlugField(
            verbose_name=_('slug'),
            help_text=_('The part of the title that is used in the URL. '
                        'Be aware if you change it, you will lose your SEO for this URL !'))
        newsbox_opts['trans_fieldnames'].append('newsbox_slug')
    if 'newsbox_summary' not in class_attrs:
        class_attrs['newsbox_summary'] = models.TextField(
            verbose_name=_('summary'),
            help_text=_('This text must be short, it will be displayed in the lists.'))
        newsbox_opts['trans_fieldnames'].append('newsbox_summary')
    if 'newsbox_body' not in class_attrs:
        class_attrs['newsbox_body'] = models.TextField(
            verbose_name=_('body'),
            null=False, blank=True)
        newsbox_opts['trans_fieldnames'].append('newsbox_body')


def newsboxseo_mcls_processor(mcls, class_name, class_bases, class_attrs, base, newsbox_opts):
    class_attrs['newsbox_meta_description'] = models.TextField(
        verbose_name=_('meta description'),
        help_text=mark_safe_lazy(
            _('The meta-description allow to improve your referencing and indicates to '
              'search engines a summary of your page. To draft her better, you can consult '
              '%(help_link)sthis help page%(link_end)s.') % {
                'help_link': _(
                    # Translators: This is the "help_link" URL for the meta-description help
                    '%(start_tag)s'
                    'https://support.google.com/webmasters/answer/35624?rd=1&hl=en#1'
                    '%(end_tag)s') % {'start_tag': '<a target="_blank" href="',
                                      'end_tag': '">'},
                'link_end': '</a>'}
        ),
        max_length=255, blank=True, null=True)
    class_attrs['newsbox_meta_keywords'] = models.CharField(
        verbose_name=_('meta keywords'),
        help_text=_('List of few keywords (4-5) separated by commas. These words must be relevant '
                    'with the contents of your page : they must be present in the contents of the '
                    'page where they should be put in \"bold\" to highlight their importance. '
                    'Also try to place them in the title of your page. Note that even if Google '
                    'does not use this meta anymore, other search engines still use these, like '
                    'Yandex, the most used search engine in Russia.'),
        max_length=255, blank=True, null=True)
    class_attrs['newsbox_canonical_url'] = models.URLField(
        verbose_name=_('canonical URL'),
        help_text=mark_safe_lazy(
            _('This field allows you to indicate to search engines the "official" URL of a '
              'duplicated contents. If your contents come from another page (of your website '
              'or another one), then you should indicate the URL of the "source" to avoid '
              '"duplicated contents" penalization of search engines. You can consult '
              '%(help_link_1)sthe moz dossier%(end_link)s on this matter or '
              '%(help_link_2)sGoogle help%(end_link)s.') % {
                'help_link_1': _(
                    # Translators: This is the "help_link_1" URL for the canonical URL help
                    '%(start_tag)s'
                    'https://moz.com/blog/canonical-url-tag-the-most-important-advancement-in-seo-practices-since-sitemaps'  # noqa
                    '%(end_tag)s') % {'start_tag': '<a target="_blank" href="',
                                      'end_tag': '">'},
                'help_link_2': _(
                    # Translators: This is the "help_link_2" URL for the canonical URL help
                    '%(start_tag)s'
                    'https://support.google.com/webmasters/answer/139066?hl=en#2'
                    '%(end_tag)s') % {'start_tag': '<a target="_blank" href="',
                                      'end_tag': '">'},
                'end_link': '</a>'}
        ),
        null=True, blank=True,)

    newsbox_opts['trans_fieldnames'] += [
        'newsbox_meta_description', 'newsbox_meta_keywords', 'newsbox_canonical_url']


###################################################################################################
###################################################################################################
class NewsboxManager(models.Manager):
    """
    Filter published news
    """

    def published(self):
        q = self.model.q_published()
        return super(NewsboxManager, self).get_queryset().filter(q)


###################################################################################################
###################################################################################################
class NewsboxModelBase(models.base.ModelBase):
    """
    Metaclass used to inject django-newsboxfunctionalities into django
    orm.
    """

    def __new__(mcls, class_name, class_bases, class_attrs):
        super_new = super(NewsboxModelBase, mcls).__new__

        # six.with_metaclass() inserts an extra class called 'NewBase' in the
        # inheritance tree: Model -> NewBase -> object. But the initialization
        # should be executed only once for a given model class.

        # attrs will never be empty for classes declared in the standard way
        # (ie. with the `class` keyword). This is quite robust.
        if class_name == 'NewBase' and class_attrs == {}:
            return super_new(mcls, class_name, class_bases, class_attrs)

        # Also ensure initialization is only performed for subclasses of Model
        # (excluding Model class itself).
        # parents = [b for b in class_bases
        #            if isinstance(b, NewsboxModelBase) and
        #            not (b.__name__ == 'NewBase' and b.__mro__ == (b, object))]

        # retrieve newsbox options in Meta class and delete these from the
        # Meta class to avoid django complain about unsupported keys.
        # We register our meta options in `_newsbox_meta`
        attr_meta = class_attrs.get('Meta', None)
        if attr_meta and not getattr(attr_meta, 'ordering', None):
            class_attrs['Meta'].ordering = ('-newsbox_publication_start_date',)
        abstract = getattr(attr_meta, 'abstract', False)
        newsbox_opts = {}
        newsbox_opts_keys = [
            'detail_url_name',
            'list_url_name',
            'metaclass_base_processor',
            'metaclass_final_processor',
            'trans_fieldnames']
        for opt in newsbox_opts_keys:
            newsbox_opt = 'newsbox_' + opt
            if hasattr(attr_meta, newsbox_opt):
                newsbox_opts[opt] = getattr(attr_meta, newsbox_opt)
                delattr(attr_meta, newsbox_opt)

        if 'trans_fieldnames' not in newsbox_opts:
            newsbox_opts['trans_fieldnames'] = []

        # register newsbox_objects manager
        class_attrs['newsbox_objects'] = NewsboxManager()

        # Call specific metaclass processor of all bases
        if not abstract:
            for base in class_bases:
                try:
                    processor = base._newsbox_meta['metaclass_base_processor']
                except (AttributeError, KeyError):
                    continue
                processor = getattr(sys.modules[base.__module__], processor)
                processor(mcls, class_name, class_bases, class_attrs, base, newsbox_opts)

            for base in class_bases:
                try:
                    processor = base._newsbox_meta['metaclass_final_processor']
                except (AttributeError, KeyError):
                    continue
                processor = getattr(sys.modules[base.__module__], processor)
                processor(mcls, class_name, class_bases, class_attrs, base, newsbox_opts)

        if 'default_manager' not in class_attrs:
            class_attrs['default_manager'] = class_attrs['newsbox_objects']
        if 'objects' not in class_attrs:
            class_attrs['objects'] = class_attrs['newsbox_objects']
        # contructs class
        cls = super_new(mcls, class_name, class_bases, class_attrs)

        # Add the detail_url_name to _newsbox_meta. if not defined, we build the
        # default one with this format : <app_label>:<model_name>_detail
        # Names ar lowered.
        if not abstract:
            if 'detail_url_name' not in newsbox_opts:
                newsbox_opts['detail_url_name'] = '%s:%s_detail' % (cls._meta.app_label.lower(),
                                                                    cls._meta.model_name.lower())
            if 'list_url_name' not in newsbox_opts:
                newsbox_opts['list_url_name'] = '%s:%s_list' % (cls._meta.app_label.lower(),
                                                                cls._meta.model_name.lower())
            newsbox_models.append(cls)
        cls.add_to_class('_newsbox_meta', newsbox_opts)
        return cls


###################################################################################################
###################################################################################################
@python_2_unicode_compatible
class NewsboxBase(six.with_metaclass(NewsboxModelBase, models.Model)):
    """
    Abstract class to build your own news
    """

    STATUS_DRAFT = 'draft'
    STATUS_PUBLISHED = 'published'
    STATUS_ARCHIVED = 'archived'
    STATUS_CHOICES = (
        (STATUS_DRAFT, _('draft')),
        (STATUS_PUBLISHED, _('published')),
        (STATUS_ARCHIVED, _('archived')),
    )

    # Automatic fields
    newsbox_creation_date = models.DateTimeField(
        verbose_name=_('creation date'),
        auto_now_add=True,
        editable=False)
    newsbox_changed_date = models.DateTimeField(
        verbose_name=_('last update date'),
        auto_now=True,
        editable=False)

    # event datetime
    newsbox_date = models.DateTimeField(
        verbose_name=_('datetime'),
        help_text=_('Datetime of the event related to this news'),
        default=None, db_index=False,
        null=True, blank=True,
    )

    # Basic Publication Fields
    newsbox_publication_start_date = models.DateTimeField(
        verbose_name=_('publication start date'),
        default=now, db_index=True,
        help_text=_(
            'When the news should go live. '
            'Status must be "Published" for news to go live.'),
        null=False, blank=False)
    newsbox_status = models.CharField(
        verbose_name=_('status'), max_length=10,
        choices=STATUS_CHOICES, default=STATUS_DRAFT,
        help_text=_('Use "Draft" to prepare your content before publishing and "Archived" to '
                    'unpublish content without deleting it'))

    default_manager = NewsboxManager()
    objects = default_manager

    class Meta:
        abstract = True
        verbose_name = _('news')
        verbose_name_plural = _('news')
        ordering = ('-newsbox_publication_start_date', )
        newsbox_metaclass_base_processor = 'newsbox_mcls_processor'
        permissions = (
            ('publish', _('Can publish')),
        )

    @classmethod
    def q_published(cls):
        # Only published News
        q = models.Q(newsbox_status=cls.STATUS_PUBLISHED)
        # exclude news with publication start date in the future
        q &= models.Q(newsbox_publication_start_date__lte=now())
        return q

    @classmethod
    def _has_perm(cls, action, user, obj=None):
        if user.is_superuser:
            return True
        return user.has_perm('%s.%s_%s' % (cls._meta.app_label, action, cls._meta.model_name), obj)

    @classmethod
    def has_publish_permission(cls, user, obj=None):
        return cls._has_perm('publish', user, obj) or cls._has_perm('change', user, obj)

    @classmethod
    def has_change_permission(cls, user, obj=None):
        return cls._has_perm('change', user, obj)

    @classmethod
    def is_future(cls, obj):
        return obj.newsbox_publication_start_date > now()

    def __str__(self):
        return six.text_type(self.newsbox_title)

    @property
    def newsbox_published(self):
        warn(('newsbox_published field is deprecated in favor of newsbox_status. '
              'Please upgrade your code.'),
             DeprecationWarning)
        return self.is_published

    @newsbox_published.setter
    def newsbox_published(self, val):
        warn(('newsbox_published field is deprecated in favor of newsbox_status. '
              'Please upgrade your code.'),
             DeprecationWarning)
        self.newsbox_status = self.STATUS_PUBLISHED

    @property
    def is_published(self):
        if self.newsbox_status != self.STATUS_PUBLISHED:
            return False
        return not self.is_future(self)

    @property
    def is_draft(self):
        return self.newsbox_status == self.STATUS_DRAFT

    @property
    def is_archived(self):
        return self.newsbox_status == self.STATUS_ARCHIVED

    def get_publication_status_explanation(self):
        """
        Get an explication about the current status to help manager to know why
        a content is (or not) published.
        for eg: publication date in the future, end publication date expired etc.
        This property must be overided if you have more complicated publication status management
        than just the status field.
        """
        if self.is_published:
            explanation = _('This content "%s" is published')
        elif self.is_draft:
            explanation = _('This content "%s" is not published because '
                            'it is currently in draft status')
        elif self.is_archived:
            explanation = _('This content "%s" is not published because '
                            'it is currently archived')
        elif self.is_future:
            explanation = _('This content "%s" is not published because '
                            'its publication start date is in the future')
        return explanation % self._meta.verbose_name

    def publish(self, commit=True):
        updated = False
        if self.newsbox_status != self.STATUS_PUBLISHED:
            self.newsbox_status = self.STATUS_PUBLISHED
            updated = True
        if self.newsbox_publication_start_date:
            now_datetime = now()
            if now_datetime < self.newsbox_publication_start_date:
                self.newsbox_publication_start_date = now_datetime
                updated = True
        if updated and commit:
            self.save()
        return updated

    def unpublish(self, commit=True):
        updated = False
        if self.newsbox_status != self.STATUS_ARCHIVED:
            self.newsbox_status = self.STATUS_ARCHIVED
            updated = True
        if updated and commit:
            self.save()
        return updated

    def get_slug(self, *args, **kwargs):
        return self.newsbox_slug

    def get_absolute_url(self, *args, **kwargs):
        return reverse(self._newsbox_meta['detail_url_name'], args=(
            self.newsbox_publication_start_date.strftime("%Y"),
            self.newsbox_publication_start_date.strftime("%m"),
            self.newsbox_publication_start_date.strftime("%d"),
            self.get_slug(),))

    def save(self, *args, **kwargs):
        # be sure to have a publication start date
        if not self.newsbox_publication_start_date:
            self.newsbox_publication_start_date = self.newsbox_creation_date
        super(NewsboxBase, self).save(*args, **kwargs)


###################################################################################################
###################################################################################################
class NewsboxExpiredBase(six.with_metaclass(NewsboxModelBase, models.Model)):
    """
    Define News which expires in time and will not be displayed in front
    """
    newsbox_publication_end_date = models.DateTimeField(
        verbose_name=_('publication end date'),
        null=True, blank=True, db_index=True,
        help_text=_('When the news will expire. Leave empty to never expire.'))

    class Meta:
        abstract = True

    @classmethod
    def q_published(cls):
        q = super(NewsboxExpiredBase, cls).q_published()
        # exclude news which are obsolete
        q &= (models.Q(newsbox_publication_end_date__gt=now()) |
              models.Q(newsbox_publication_end_date__isnull=True))
        return q

    @classmethod
    def is_expired(cls, obj):
        return obj.newsbox_publication_end_date and obj.newsbox_publication_end_date < now()

    @property
    def is_published(self):
        if not super(NewsboxExpiredBase, self).is_published:
            return False
        return not self.is_expired(self)

    def get_publication_status_explanation(self):
        """
        Get an explication about the current status to help manager to know why
        a content is (or not) published.
        for eg: publication date in the future, end publication date expired etc.
        This property must be overided if you have more complicated publication status management
        than just the status field.
        """
        if not self.is_draft and not self.is_archived and self.is_expired:
            explanation = _('This content "%s" is not published because '
                            'its publication end date is in the past')
            return explanation % self._meta.verbose_name
        return super(NewsboxExpiredBase, self).get_publication_status_explanation()

    def publish(self, commit=True):
        updated = super(NewsboxExpiredBase, self).publish(commit=False)
        if self.newsbox_publication_end_date:
            if now() > self.newsbox_publication_end_date:
                self.newsbox_publication_end_date = None
                updated = True
        if updated and commit:
            self.save()
        return updated


###################################################################################################
###################################################################################################
class NewsboxSEOBase(six.with_metaclass(NewsboxModelBase, models.Model)):
    """
    Define News which have SEO fields
    """

    # SEO Fields
    newsbox_indexed = models.PositiveSmallIntegerField(
        verbose_name=_('indexed'),
        default=1,
        choices=((0, _('Not indexed on search engines'), ),
                 (1, _('Indexed on search engines'), )),
        help_text=_('An unindexed news will not be indexed by search engines.'))

    class Meta:
        abstract = True
        newsbox_metaclass_base_processor = 'newsboxseo_mcls_processor'

    def get_meta_informations(self):
        if not hasattr(self, '_meta_informations'):
            self._meta_informations = {
                'description': self.newsbox_meta_description,
                'keywords': self.newsbox_meta_keywords,
                'robots': [],
                'title': '%s' % self,
            }
            if not self.newsbox_indexed:
                self._meta_informations['robots'].append('noindex')
            if self.newsbox_meta_description:
                self._meta_informations['robots'].append('noodp')
        return self._meta_informations