1 files changed, 654 insertions, 654 deletions
diff --git a/forum/models.py b/forum/models.py
index 570db274..b966ccb0 100644
--- a/forum/models.py
+++ b/forum/models.py
@@ -1,654 +1,654 @@
-# encoding:utf-8
-import datetime
-import hashlib
-from urllib import quote_plus, urlencode
-from django.db import models
-from django.utils.html import strip_tags
-from django.core.urlresolvers import reverse
-from django.contrib.auth.models import User
-from django.contrib.contenttypes import generic
-from django.contrib.contenttypes.models import ContentType
-from django.template.defaultfilters import slugify
-from django.db.models.signals import post_delete, post_save, pre_save
-from django.utils.translation import ugettext as _
-import django.dispatch
-
-from forum.managers import *
-from const import *
-
-class Tag(models.Model):
-    name       = models.CharField(max_length=255, unique=True)
-    created_by = models.ForeignKey(User, related_name='created_tags')
-    deleted         = models.BooleanField(default=False)
-    deleted_at      = models.DateTimeField(null=True, blank=True)
-    deleted_by      = models.ForeignKey(User, null=True, blank=True, related_name='deleted_tags')
-    # Denormalised data
-    used_count = models.PositiveIntegerField(default=0)
-
-    objects = TagManager()
-
-    class Meta:
-        db_table = u'tag'
-        ordering = ('-used_count', 'name')
-
-    def __unicode__(self):
-        return self.name
-
-class Comment(models.Model):
-    content_type   = models.ForeignKey(ContentType)
-    object_id      = models.PositiveIntegerField()
-    content_object = generic.GenericForeignKey('content_type', 'object_id')
-    user           = models.ForeignKey(User, related_name='comments')
-    comment        = models.CharField(max_length=300)
-    added_at       = models.DateTimeField(default=datetime.datetime.now)
-
-    class Meta:
-        ordering = ('-added_at',)
-        db_table = u'comment'
-    def __unicode__(self):
-        return self.comment
-
-class Vote(models.Model):
-    VOTE_UP = +1
-    VOTE_DOWN = -1
-    VOTE_CHOICES = (
-        (VOTE_UP,   u'Up'),
-        (VOTE_DOWN, u'Down'),
-    )
-
-    content_type   = models.ForeignKey(ContentType)
-    object_id      = models.PositiveIntegerField()
-    content_object = generic.GenericForeignKey('content_type', 'object_id')
-    user           = models.ForeignKey(User, related_name='votes')
-    vote           = models.SmallIntegerField(choices=VOTE_CHOICES)
-    voted_at       = models.DateTimeField(default=datetime.datetime.now)
-
-    objects = VoteManager()
-
-    class Meta:
-        unique_together = ('content_type', 'object_id', 'user')
-        db_table = u'vote'
-    def __unicode__(self):
-        return '[%s] voted at %s: %s' %(self.user, self.voted_at, self.vote)
-
-    def is_upvote(self):
-        return self.vote == self.VOTE_UP
-
-    def is_downvote(self):
-        return self.vote == self.VOTE_DOWN
-
-class FlaggedItem(models.Model):
-    """A flag on a Question or Answer indicating offensive content."""
-    content_type   = models.ForeignKey(ContentType)
-    object_id      = models.PositiveIntegerField()
-    content_object = generic.GenericForeignKey('content_type', 'object_id')
-    user           = models.ForeignKey(User, related_name='flagged_items')
-    flagged_at     = models.DateTimeField(default=datetime.datetime.now)
-
-    objects = FlaggedItemManager()
-
-    class Meta:
-        unique_together = ('content_type', 'object_id', 'user')
-        db_table = u'flagged_item'
-    def __unicode__(self):
-        return '[%s] flagged at %s' %(self.user, self.flagged_at)
-
-class Question(models.Model):
-    title    = models.CharField(max_length=300)
-    author   = models.ForeignKey(User, related_name='questions')
-    added_at = models.DateTimeField(default=datetime.datetime.now)
-    tags     = models.ManyToManyField(Tag, related_name='questions')
-    # Status
-    wiki            = models.BooleanField(default=False)
-    wikified_at     = models.DateTimeField(null=True, blank=True)
-    answer_accepted = models.BooleanField(default=False)
-    closed          = models.BooleanField(default=False)
-    closed_by       = models.ForeignKey(User, null=True, blank=True, related_name='closed_questions')
-    closed_at       = models.DateTimeField(null=True, blank=True)
-    close_reason    = models.SmallIntegerField(choices=CLOSE_REASONS, null=True, blank=True)
-    deleted         = models.BooleanField(default=False)
-    deleted_at      = models.DateTimeField(null=True, blank=True)
-    deleted_by      = models.ForeignKey(User, null=True, blank=True, related_name='deleted_questions')
-    locked          = models.BooleanField(default=False)
-    locked_by       = models.ForeignKey(User, null=True, blank=True, related_name='locked_questions')
-    locked_at       = models.DateTimeField(null=True, blank=True)
-    # Denormalised data
-    score                = models.IntegerField(default=0)
-    vote_up_count        = models.IntegerField(default=0)
-    vote_down_count      = models.IntegerField(default=0)
-    answer_count         = models.PositiveIntegerField(default=0)
-    comment_count        = models.PositiveIntegerField(default=0)
-    view_count           = models.PositiveIntegerField(default=0)
-    offensive_flag_count = models.SmallIntegerField(default=0)
-    favourite_count      = models.PositiveIntegerField(default=0)
-    last_edited_at       = models.DateTimeField(null=True, blank=True)
-    last_edited_by       = models.ForeignKey(User, null=True, blank=True, related_name='last_edited_questions')
-    last_activity_at     = models.DateTimeField(default=datetime.datetime.now)
-    last_activity_by     = models.ForeignKey(User, related_name='last_active_in_questions')
-    tagnames             = models.CharField(max_length=125)
-    summary              = models.CharField(max_length=180)
-    html                 = models.TextField()
-    comments             = generic.GenericRelation(Comment)
-    votes                = generic.GenericRelation(Vote)
-    flagged_items        = generic.GenericRelation(FlaggedItem)
-
-    objects = QuestionManager()
-
-    def save(self, **kwargs):
-        """
-        Overridden to manually manage addition of tags when the object
-        is first saved.
-
-        This is required as we're using ``tagnames`` as the sole means of
-        adding and editing tags.
-        """
-        initial_addition = (self.id is None)
-        super(Question, self).save(**kwargs)
-        if initial_addition:
-            tags = Tag.objects.get_or_create_multiple(self.tagname_list(),
-                                                      self.author)
-            self.tags.add(*tags)
-            Tag.objects.update_use_counts(tags)
-
-    def tagname_list(self):
-        """Creates a list of Tag names from the ``tagnames`` attribute."""
-        return [name for name in self.tagnames.split(u' ')]
-
-    def get_absolute_url(self):
-        return '%s%s' % (reverse('question', args=[self.id]), self.title)
-
-    def has_favorite_by_user(self, user):
-        if not user.is_authenticated():
-            return False
-        return FavoriteQuestion.objects.filter(question=self, user=user).count() > 0
-
-    def get_answer_count_by_user(self, user_id):
-        query_set = Answer.objects.filter(author__id=user_id)
-        return query_set.filter(question=self).count()
-
-    def get_question_title(self):
-        if self.closed:
-            attr = CONST['closed'] 
-        elif self.deleted:
-            attr = CONST['deleted']
-        else:
-            attr = None
-        return u'%s %s' % (self.title, attr) if attr is not None else self.title
-
-    def get_revision_url(self):
-        return reverse('question_revisions', args=[self.id])
-
-    def get_latest_revision(self):
-        return self.revisions.all()[0]
-
-    def __unicode__(self):
-        return self.title
-
-    class Meta:
-        db_table = u'question'
-
-class QuestionRevision(models.Model):
-    """A revision of a Question."""
-    question   = models.ForeignKey(Question, related_name='revisions')
-    revision   = models.PositiveIntegerField(blank=True)
-    title      = models.CharField(max_length=300)
-    author     = models.ForeignKey(User, related_name='question_revisions')
-    revised_at = models.DateTimeField()
-    tagnames   = models.CharField(max_length=125)
-    summary    = models.CharField(max_length=300, blank=True)
-    text       = models.TextField()
-
-    class Meta:
-        db_table = u'question_revision'
-        ordering = ('-revision',)
-
-    def get_question_title(self):
-        return self.question.title
-
-    def get_absolute_url(self):
-        return '/questions/%s/revisions' % (self.question.id)
-
-    def save(self, **kwargs):
-        """Looks up the next available revision number."""
-        if not self.revision:
-            self.revision = QuestionRevision.objects.filter(
-                question=self.question).values_list('revision',
-                                                    flat=True)[0] + 1
-        super(QuestionRevision, self).save(**kwargs)
-
-    def __unicode__(self):
-        return u'revision %s of %s' % (self.revision, self.title)
-
-class Answer(models.Model):
-    question = models.ForeignKey(Question, related_name='answers')
-    author   = models.ForeignKey(User, related_name='answers')
-    added_at = models.DateTimeField(default=datetime.datetime.now)
-    # Status
-    wiki        = models.BooleanField(default=False)
-    wikified_at = models.DateTimeField(null=True, blank=True)
-    accepted    = models.BooleanField(default=False)
-    accepted_at = models.DateTimeField(null=True, blank=True)
-    deleted     = models.BooleanField(default=False)
-    deleted_by  = models.ForeignKey(User, null=True, blank=True, related_name='deleted_answers')
-    locked      = models.BooleanField(default=False)
-    locked_by   = models.ForeignKey(User, null=True, blank=True, related_name='locked_answers')
-    locked_at   = models.DateTimeField(null=True, blank=True)
-    # Denormalised data
-    score                = models.IntegerField(default=0)
-    vote_up_count        = models.IntegerField(default=0)
-    vote_down_count      = models.IntegerField(default=0)
-    comment_count        = models.PositiveIntegerField(default=0)
-    offensive_flag_count = models.SmallIntegerField(default=0)
-    last_edited_at       = models.DateTimeField(null=True, blank=True)
-    last_edited_by       = models.ForeignKey(User, null=True, blank=True, related_name='last_edited_answers')
-    html                 = models.TextField()
-    comments             = generic.GenericRelation(Comment)
-    votes                = generic.GenericRelation(Vote)
-    flagged_items        = generic.GenericRelation(FlaggedItem)
-
-    objects = AnswerManager()
-
-    def get_user_vote(self, user):
-        votes = self.votes.filter(user=user)
-        if votes.count() > 0:
-            return votes[0]
-        else:
-            return None
-
-    def get_latest_revision(self):
-        return self.revisions.all()[0]
-
-    def get_question_title(self):
-        return self.question.title
-
-    def get_absolute_url(self):
-        return '%s%s#%s' % (reverse('question', args=[self.question.id]), self.question.title, self.id)
-
-    class Meta:
-        db_table = u'answer'
-
-    def __unicode__(self):
-        return self.html
-
-class AnswerRevision(models.Model):
-    """A revision of an Answer."""
-    answer     = models.ForeignKey(Answer, related_name='revisions')
-    revision   = models.PositiveIntegerField()
-    author     = models.ForeignKey(User, related_name='answer_revisions')
-    revised_at = models.DateTimeField()
-    summary    = models.CharField(max_length=300, blank=True)
-    text       = models.TextField()
-
-    def get_absolute_url(self):
-        return '/answers/%s/revisions' % (self.answer.id)
-
-    def get_question_title(self):
-        return self.answer.question.title
-
-    class Meta:
-        db_table = u'answer_revision'
-        ordering = ('-revision',)
-
-    def save(self, **kwargs):
-        """Looks up the next available revision number if not set."""
-        if not self.revision:
-            self.revision = AnswerRevision.objects.filter(
-                answer=self.answer).values_list('revision',
-                                                flat=True)[0] + 1
-        super(AnswerRevision, self).save(**kwargs)
-
-class FavoriteQuestion(models.Model):
-    """A favorite Question of a User."""
-    question      = models.ForeignKey(Question)
-    user          = models.ForeignKey(User, related_name='user_favorite_questions')
-    added_at = models.DateTimeField(default=datetime.datetime.now)
-    class Meta:
-        db_table = u'favorite_question'
-    def __unicode__(self):
-        return '[%s] favorited at %s' %(self.user, self.added_at)
-
-class Badge(models.Model):
-    """Awarded for notable actions performed on the site by Users."""
-    GOLD = 1
-    SILVER = 2
-    BRONZE = 3
-    TYPE_CHOICES = (
-        (GOLD,   _('gold')),
-        (SILVER, _('silver')),
-        (BRONZE, _('bronze')),
-    )
-
-    name        = models.CharField(max_length=50)
-    type        = models.SmallIntegerField(choices=TYPE_CHOICES)
-    slug        = models.SlugField(max_length=50, blank=True)
-    description = models.CharField(max_length=300)
-    multiple    = models.BooleanField(default=False)
-    # Denormalised data
-    awarded_count = models.PositiveIntegerField(default=0)
-
-    class Meta:
-        db_table = u'badge'
-        ordering = ('name',)
-        unique_together = ('name', 'type')
-
-    def __unicode__(self):
-        return u'%s: %s' % (self.get_type_display(), self.name)
-
-    def save(self, **kwargs):
-        if not self.slug:
-            self.slug = self.name#slugify(self.name)
-        super(Badge, self).save(**kwargs)
-
-    def get_absolute_url(self):
-        return '%s%s/' % (reverse('badge', args=[self.id]), self.slug)
-
-class Award(models.Model):
-    """The awarding of a Badge to a User."""
-    user       = models.ForeignKey(User, related_name='award_user')
-    badge      = models.ForeignKey(Badge, related_name='award_badge')
-    content_type   = models.ForeignKey(ContentType)
-    object_id      = models.PositiveIntegerField()
-    content_object = generic.GenericForeignKey('content_type', 'object_id')
-    awarded_at = models.DateTimeField(default=datetime.datetime.now)
-    notified   = models.BooleanField(default=False)
-    objects = AwardManager()
-    
-    def __unicode__(self):
-        return u'[%s] is awarded a badge [%s] at %s' % (self.user.username, self.badge.name, self.awarded_at)
-
-    class Meta:
-        db_table = u'award'
-
-class Repute(models.Model):
-    """The reputation histories for user"""
-    user     = models.ForeignKey(User)
-    positive = models.SmallIntegerField(default=0)
-    negative = models.SmallIntegerField(default=0)
-    question = models.ForeignKey(Question)
-    reputed_at = models.DateTimeField(default=datetime.datetime.now)
-    reputation_type = models.SmallIntegerField(choices=TYPE_REPUTATION)
-    reputation = models.IntegerField(default=1)
-    objects = ReputeManager()
-
-    def __unicode__(self):
-        return u'[%s]\' reputation changed at %s' % (self.user.username, self.reputed_at)
-
-    class Meta:
-        db_table = u'repute'
-
-class Activity(models.Model):
-    """
-    We keep some history data for user activities
-    """
-    user = models.ForeignKey(User)
-    activity_type = models.SmallIntegerField(choices=TYPE_ACTIVITY)
-    active_at = models.DateTimeField(default=datetime.datetime.now)
-    content_type   = models.ForeignKey(ContentType)
-    object_id      = models.PositiveIntegerField()
-    content_object = generic.GenericForeignKey('content_type', 'object_id')
-    is_auditted    = models.BooleanField(default=False)
-
-    def __unicode__(self):
-        return u'[%s] was active at %s' % (self.user.username, self.active_at)
-
-    class Meta:
-        db_table = u'activity'
-
-class Book(models.Model):
-    """
-    Model for book info
-    """
-    user = models.ForeignKey(User)
-    title = models.CharField(max_length=255)
-    short_name = models.CharField(max_length=255)
-    author = models.CharField(max_length=255)
-    price = models.DecimalField(max_digits=6, decimal_places=2)
-    pages = models.SmallIntegerField()
-    published_at = models.DateTimeField()
-    publication = models.CharField(max_length=255)
-    cover_img = models.CharField(max_length=255)
-    tagnames = models.CharField(max_length=125)
-    added_at = models.DateTimeField()
-    last_edited_at = models.DateTimeField()
-    questions = models.ManyToManyField(Question, related_name='book', db_table='book_question')
-    
-    def get_absolute_url(self):
-        return '%s' % reverse('book', args=[self.short_name])
-        
-    def __unicode__(self):
-        return self.title
-    class Meta:
-        db_table = u'book'
-
-class BookAuthorInfo(models.Model):
-    """
-    Model for book author info
-    """
-    user = models.ForeignKey(User)
-    book = models.ForeignKey(Book)
-    blog_url = models.CharField(max_length=255)
-    added_at = models.DateTimeField()
-    last_edited_at = models.DateTimeField()
-    
-    class Meta:
-        db_table = u'book_author_info'
-    
-class BookAuthorRss(models.Model):
-    """
-    Model for book author blog rss
-    """
-    user = models.ForeignKey(User)
-    book = models.ForeignKey(Book)
-    title = models.CharField(max_length=255)
-    url = models.CharField(max_length=255)
-    rss_created_at = models.DateTimeField()
-    added_at = models.DateTimeField()
-    
-    class Meta:
-        db_table = u'book_author_rss'
-
-# User extend properties
-QUESTIONS_PER_PAGE_CHOICES = (
-   (10, u'10'),
-   (30, u'30'),
-   (50, u'50'),
-)
-
-User.add_to_class('reputation', models.PositiveIntegerField(default=1))
-User.add_to_class('gravatar', models.CharField(max_length=32))
-User.add_to_class('favorite_questions',
-                  models.ManyToManyField(Question, through=FavoriteQuestion,
-                                         related_name='favorited_by'))
-User.add_to_class('badges', models.ManyToManyField(Badge, through=Award,
-                                                   related_name='awarded_to'))
-User.add_to_class('gold', models.SmallIntegerField(default=0))
-User.add_to_class('silver', models.SmallIntegerField(default=0))
-User.add_to_class('bronze', models.SmallIntegerField(default=0))
-User.add_to_class('questions_per_page',
-                  models.SmallIntegerField(choices=QUESTIONS_PER_PAGE_CHOICES, default=10))
-User.add_to_class('last_seen',
-                  models.DateTimeField(default=datetime.datetime.now))
-User.add_to_class('real_name', models.CharField(max_length=100, blank=True))
-User.add_to_class('website', models.URLField(max_length=200, blank=True))
-User.add_to_class('location', models.CharField(max_length=100, blank=True))
-User.add_to_class('date_of_birth', models.DateField(null=True, blank=True))
-User.add_to_class('about', models.TextField(blank=True))
-
-# custom signal
-tags_updated = django.dispatch.Signal(providing_args=["question"])
-edit_question_or_answer = django.dispatch.Signal(providing_args=["instance", "modified_by"])
-delete_post_or_answer = django.dispatch.Signal(providing_args=["instance", "deleted_by"])
-mark_offensive = django.dispatch.Signal(providing_args=["instance", "mark_by"])
-user_updated = django.dispatch.Signal(providing_args=["instance", "updated_by"])
-def get_messages(self):
-        messages = []
-        for m in self.message_set.all():
-            messages.append(m.message)
-        return messages
-
-def delete_messages(self):
-    self.message_set.all().delete()
-
-def get_profile_url(self):
-    """Returns the URL for this User's profile."""
-    return '%s%s/' % (reverse('user', args=[self.id]), self.username)
-User.add_to_class('get_profile_url', get_profile_url)
-User.add_to_class('get_messages', get_messages)
-User.add_to_class('delete_messages', delete_messages)
-
-def calculate_gravatar_hash(instance, **kwargs):
-    """Calculates a User's gravatar hash from their email address."""
-    if kwargs.get('raw', False):
-        return
-    instance.gravatar = hashlib.md5(instance.email).hexdigest()
-
-def record_ask_event(instance, created, **kwargs):
-    if created:
-        activity = Activity(user=instance.author, active_at=instance.added_at, content_object=instance, activity_type=TYPE_ACTIVITY_ASK_QUESTION)
-        activity.save()
-
-def record_answer_event(instance, created, **kwargs):
-    if created:
-        activity = Activity(user=instance.author, active_at=instance.added_at, content_object=instance, activity_type=TYPE_ACTIVITY_ANSWER)
-        activity.save()
-
-def record_comment_event(instance, created, **kwargs):
-    if created:
-        from django.contrib.contenttypes.models import ContentType
-        question_type = ContentType.objects.get_for_model(Question)
-        question_type_id = question_type.id
-        type = TYPE_ACTIVITY_COMMENT_QUESTION if instance.content_type_id == question_type_id else TYPE_ACTIVITY_COMMENT_ANSWER
-        activity = Activity(user=instance.user, active_at=instance.added_at, content_object=instance, activity_type=type)
-        activity.save()
-
-def record_revision_question_event(instance, created, **kwargs):
-    if created and instance.revision <> 1:
-        activity = Activity(user=instance.author, active_at=instance.revised_at, content_object=instance, activity_type=TYPE_ACTIVITY_UPDATE_QUESTION)
-        activity.save()
-
-def record_revision_answer_event(instance, created, **kwargs):
-    if created and instance.revision <> 1:
-        activity = Activity(user=instance.author, active_at=instance.revised_at, content_object=instance, activity_type=TYPE_ACTIVITY_UPDATE_ANSWER)
-        activity.save()
-
-def record_award_event(instance, created, **kwargs):
-    """
-    After we awarded a badge to user, we need to record this activity and notify user.
-    We also recaculate awarded_count of this badge and user information.
-    """
-    if created:
-        activity = Activity(user=instance.user, active_at=instance.awarded_at, content_object=instance,
-            activity_type=TYPE_ACTIVITY_PRIZE)
-        activity.save()
-
-        instance.badge.awarded_count += 1
-        instance.badge.save()
-
-        if instance.badge.type == Badge.GOLD:
-            instance.user.gold += 1
-        if instance.badge.type == Badge.SILVER:
-            instance.user.silver += 1
-        if instance.badge.type == Badge.BRONZE:
-            instance.user.bronze += 1
-        instance.user.save()
-
-def notify_award_message(instance, created, **kwargs):
-    """
-    Notify users when they have been awarded badges by using Django message.
-    """
-    if created:
-        user = instance.user
-        user.message_set.create(message=u"%s" % instance.badge.name)
-
-def record_answer_accepted(instance, created, **kwargs):
-    """
-    when answer is accepted, we record this for question author - who accepted it.
-    """
-    if not created and instance.accepted:
-        activity = Activity(user=instance.question.author, active_at=datetime.datetime.now(), \
-            content_object=instance, activity_type=TYPE_ACTIVITY_MARK_ANSWER)
-        activity.save()
-
-def update_last_seen(instance, created, **kwargs):
-    """
-    when user has activities, we update 'last_seen' time stamp for him
-    """
-    user = instance.user
-    user.last_seen = datetime.datetime.now()
-    user.save()
-
-def record_vote(instance, created, **kwargs):
-    """
-    when user have voted
-    """
-    if created:
-        if instance.vote == 1:
-            vote_type = TYPE_ACTIVITY_VOTE_UP
-        else:
-            vote_type = TYPE_ACTIVITY_VOTE_DOWN
-
-        activity = Activity(user=instance.user, active_at=instance.voted_at, content_object=instance, activity_type=vote_type)
-        activity.save()
-
-def record_cancel_vote(instance, **kwargs):
-    """
-    when user canceled vote, the vote will be deleted.
-    """
-    activity = Activity(user=instance.user, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_CANCEL_VOTE)
-    activity.save()
-
-def record_delete_question(instance, delete_by, **kwargs):
-    """
-    when user deleted the question
-    """
-    if instance.__class__ == "Question":
-        activity_type = TYPE_ACTIVITY_DELETE_QUESTION
-    else:
-        activity_type = TYPE_ACTIVITY_DELETE_ANSWER
-
-    activity = Activity(user=delete_by, active_at=datetime.datetime.now(), content_object=instance, activity_type=activity_type)
-    activity.save()
-
-def record_mark_offensive(instance, mark_by, **kwargs):
-    activity = Activity(user=mark_by, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_MARK_OFFENSIVE)
-    activity.save()
-
-def record_update_tags(question, **kwargs):
-    """
-    when user updated tags of the question
-    """
-    activity = Activity(user=question.author, active_at=datetime.datetime.now(), content_object=question, activity_type=TYPE_ACTIVITY_UPDATE_TAGS)
-    activity.save()
-
-def record_favorite_question(instance, created, **kwargs):
-    """
-    when user add the question in him favorite questions list.
-    """
-    if created:
-        activity = Activity(user=instance.user, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_FAVORITE)
-        activity.save()
-
-def record_user_full_updated(instance, **kwargs):
-    activity = Activity(user=instance, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_USER_FULL_UPDATED)
-    activity.save()
-
-#signal for User modle save changes
-pre_save.connect(calculate_gravatar_hash, sender=User)
-post_save.connect(record_ask_event, sender=Question)
-post_save.connect(record_answer_event, sender=Answer)
-post_save.connect(record_comment_event, sender=Comment)
-post_save.connect(record_revision_question_event, sender=QuestionRevision)
-post_save.connect(record_revision_answer_event, sender=AnswerRevision)
-post_save.connect(record_award_event, sender=Award)
-post_save.connect(notify_award_message, sender=Award)
-post_save.connect(record_answer_accepted, sender=Answer)
-post_save.connect(update_last_seen, sender=Activity)
-post_save.connect(record_vote, sender=Vote)
-post_delete.connect(record_cancel_vote, sender=Vote)
-delete_post_or_answer.connect(record_delete_question, sender=Question)
-delete_post_or_answer.connect(record_delete_question, sender=Answer)
-mark_offensive.connect(record_mark_offensive, sender=Question)
-mark_offensive.connect(record_mark_offensive, sender=Answer)
-tags_updated.connect(record_update_tags, sender=Question)
-post_save.connect(record_favorite_question, sender=FavoriteQuestion)
-user_updated.connect(record_user_full_updated, sender=User)
+# encoding:utf-8
+import datetime
+import hashlib
+from urllib import quote_plus, urlencode
+from django.db import models
+from django.utils.html import strip_tags
+from django.core.urlresolvers import reverse
+from django.contrib.auth.models import User
+from django.contrib.contenttypes import generic
+from django.contrib.contenttypes.models import ContentType
+from django.template.defaultfilters import slugify
+from django.db.models.signals import post_delete, post_save, pre_save
+from django.utils.translation import ugettext as _
+import django.dispatch
+
+from forum.managers import *
+from const import *
+
+class Tag(models.Model):
+    name       = models.CharField(max_length=255, unique=True)
+    created_by = models.ForeignKey(User, related_name='created_tags')
+    deleted         = models.BooleanField(default=False)
+    deleted_at      = models.DateTimeField(null=True, blank=True)
+    deleted_by      = models.ForeignKey(User, null=True, blank=True, related_name='deleted_tags')
+    # Denormalised data
+    used_count = models.PositiveIntegerField(default=0)
+
+    objects = TagManager()
+
+    class Meta:
+        db_table = u'tag'
+        ordering = ('-used_count', 'name')
+
+    def __unicode__(self):
+        return self.name
+
+class Comment(models.Model):
+    content_type   = models.ForeignKey(ContentType)
+    object_id      = models.PositiveIntegerField()
+    content_object = generic.GenericForeignKey('content_type', 'object_id')
+    user           = models.ForeignKey(User, related_name='comments')
+    comment        = models.CharField(max_length=300)
+    added_at       = models.DateTimeField(default=datetime.datetime.now)
+
+    class Meta:
+        ordering = ('-added_at',)
+        db_table = u'comment'
+    def __unicode__(self):
+        return self.comment
+
+class Vote(models.Model):
+    VOTE_UP = +1
+    VOTE_DOWN = -1
+    VOTE_CHOICES = (
+        (VOTE_UP,   u'Up'),
+        (VOTE_DOWN, u'Down'),
+    )
+
+    content_type   = models.ForeignKey(ContentType)
+    object_id      = models.PositiveIntegerField()
+    content_object = generic.GenericForeignKey('content_type', 'object_id')
+    user           = models.ForeignKey(User, related_name='votes')
+    vote           = models.SmallIntegerField(choices=VOTE_CHOICES)
+    voted_at       = models.DateTimeField(default=datetime.datetime.now)
+
+    objects = VoteManager()
+
+    class Meta:
+        unique_together = ('content_type', 'object_id', 'user')
+        db_table = u'vote'
+    def __unicode__(self):
+        return '[%s] voted at %s: %s' %(self.user, self.voted_at, self.vote)
+
+    def is_upvote(self):
+        return self.vote == self.VOTE_UP
+
+    def is_downvote(self):
+        return self.vote == self.VOTE_DOWN
+
+class FlaggedItem(models.Model):
+    """A flag on a Question or Answer indicating offensive content."""
+    content_type   = models.ForeignKey(ContentType)
+    object_id      = models.PositiveIntegerField()
+    content_object = generic.GenericForeignKey('content_type', 'object_id')
+    user           = models.ForeignKey(User, related_name='flagged_items')
+    flagged_at     = models.DateTimeField(default=datetime.datetime.now)
+
+    objects = FlaggedItemManager()
+
+    class Meta:
+        unique_together = ('content_type', 'object_id', 'user')
+        db_table = u'flagged_item'
+    def __unicode__(self):
+        return '[%s] flagged at %s' %(self.user, self.flagged_at)
+
+class Question(models.Model):
+    title    = models.CharField(max_length=300)
+    author   = models.ForeignKey(User, related_name='questions')
+    added_at = models.DateTimeField(default=datetime.datetime.now)
+    tags     = models.ManyToManyField(Tag, related_name='questions')
+    # Status
+    wiki            = models.BooleanField(default=False)
+    wikified_at     = models.DateTimeField(null=True, blank=True)
+    answer_accepted = models.BooleanField(default=False)
+    closed          = models.BooleanField(default=False)
+    closed_by       = models.ForeignKey(User, null=True, blank=True, related_name='closed_questions')
+    closed_at       = models.DateTimeField(null=True, blank=True)
+    close_reason    = models.SmallIntegerField(choices=CLOSE_REASONS, null=True, blank=True)
+    deleted         = models.BooleanField(default=False)
+    deleted_at      = models.DateTimeField(null=True, blank=True)
+    deleted_by      = models.ForeignKey(User, null=True, blank=True, related_name='deleted_questions')
+    locked          = models.BooleanField(default=False)
+    locked_by       = models.ForeignKey(User, null=True, blank=True, related_name='locked_questions')
+    locked_at       = models.DateTimeField(null=True, blank=True)
+    # Denormalised data
+    score                = models.IntegerField(default=0)
+    vote_up_count        = models.IntegerField(default=0)
+    vote_down_count      = models.IntegerField(default=0)
+    answer_count         = models.PositiveIntegerField(default=0)
+    comment_count        = models.PositiveIntegerField(default=0)
+    view_count           = models.PositiveIntegerField(default=0)
+    offensive_flag_count = models.SmallIntegerField(default=0)
+    favourite_count      = models.PositiveIntegerField(default=0)
+    last_edited_at       = models.DateTimeField(null=True, blank=True)
+    last_edited_by       = models.ForeignKey(User, null=True, blank=True, related_name='last_edited_questions')
+    last_activity_at     = models.DateTimeField(default=datetime.datetime.now)
+    last_activity_by     = models.ForeignKey(User, related_name='last_active_in_questions')
+    tagnames             = models.CharField(max_length=125)
+    summary              = models.CharField(max_length=180)
+    html                 = models.TextField()
+    comments             = generic.GenericRelation(Comment)
+    votes                = generic.GenericRelation(Vote)
+    flagged_items        = generic.GenericRelation(FlaggedItem)
+
+    objects = QuestionManager()
+
+    def save(self, **kwargs):
+        """
+        Overridden to manually manage addition of tags when the object
+        is first saved.
+
+        This is required as we're using ``tagnames`` as the sole means of
+        adding and editing tags.
+        """
+        initial_addition = (self.id is None)
+        super(Question, self).save(**kwargs)
+        if initial_addition:
+            tags = Tag.objects.get_or_create_multiple(self.tagname_list(),
+                                                      self.author)
+            self.tags.add(*tags)
+            Tag.objects.update_use_counts(tags)
+
+    def tagname_list(self):
+        """Creates a list of Tag names from the ``tagnames`` attribute."""
+        return [name for name in self.tagnames.split(u' ')]
+
+    def get_absolute_url(self):
+        return '%s%s' % (reverse('question', args=[self.id]), self.title.replace(' ', '-'))
+
+    def has_favorite_by_user(self, user):
+        if not user.is_authenticated():
+            return False
+        return FavoriteQuestion.objects.filter(question=self, user=user).count() > 0
+
+    def get_answer_count_by_user(self, user_id):
+        query_set = Answer.objects.filter(author__id=user_id)
+        return query_set.filter(question=self).count()
+
+    def get_question_title(self):
+        if self.closed:
+            attr = CONST['closed'] 
+        elif self.deleted:
+            attr = CONST['deleted']
+        else:
+            attr = None
+        return u'%s %s' % (self.title, attr) if attr is not None else self.title
+
+    def get_revision_url(self):
+        return reverse('question_revisions', args=[self.id])
+
+    def get_latest_revision(self):
+        return self.revisions.all()[0]
+
+    def __unicode__(self):
+        return self.title
+
+    class Meta:
+        db_table = u'question'
+
+class QuestionRevision(models.Model):
+    """A revision of a Question."""
+    question   = models.ForeignKey(Question, related_name='revisions')
+    revision   = models.PositiveIntegerField(blank=True)
+    title      = models.CharField(max_length=300)
+    author     = models.ForeignKey(User, related_name='question_revisions')
+    revised_at = models.DateTimeField()
+    tagnames   = models.CharField(max_length=125)
+    summary    = models.CharField(max_length=300, blank=True)
+    text       = models.TextField()
+
+    class Meta:
+        db_table = u'question_revision'
+        ordering = ('-revision',)
+
+    def get_question_title(self):
+        return self.question.title
+
+    def get_absolute_url(self):
+        return '/questions/%s/revisions' % (self.question.id)
+
+    def save(self, **kwargs):
+        """Looks up the next available revision number."""
+        if not self.revision:
+            self.revision = QuestionRevision.objects.filter(
+                question=self.question).values_list('revision',
+                                                    flat=True)[0] + 1
+        super(QuestionRevision, self).save(**kwargs)
+
+    def __unicode__(self):
+        return u'revision %s of %s' % (self.revision, self.title)
+
+class Answer(models.Model):
+    question = models.ForeignKey(Question, related_name='answers')
+    author   = models.ForeignKey(User, related_name='answers')
+    added_at = models.DateTimeField(default=datetime.datetime.now)
+    # Status
+    wiki        = models.BooleanField(default=False)
+    wikified_at = models.DateTimeField(null=True, blank=True)
+    accepted    = models.BooleanField(default=False)
+    accepted_at = models.DateTimeField(null=True, blank=True)
+    deleted     = models.BooleanField(default=False)
+    deleted_by  = models.ForeignKey(User, null=True, blank=True, related_name='deleted_answers')
+    locked      = models.BooleanField(default=False)
+    locked_by   = models.ForeignKey(User, null=True, blank=True, related_name='locked_answers')
+    locked_at   = models.DateTimeField(null=True, blank=True)
+    # Denormalised data
+    score                = models.IntegerField(default=0)
+    vote_up_count        = models.IntegerField(default=0)
+    vote_down_count      = models.IntegerField(default=0)
+    comment_count        = models.PositiveIntegerField(default=0)
+    offensive_flag_count = models.SmallIntegerField(default=0)
+    last_edited_at       = models.DateTimeField(null=True, blank=True)
+    last_edited_by       = models.ForeignKey(User, null=True, blank=True, related_name='last_edited_answers')
+    html                 = models.TextField()
+    comments             = generic.GenericRelation(Comment)
+    votes                = generic.GenericRelation(Vote)
+    flagged_items        = generic.GenericRelation(FlaggedItem)
+
+    objects = AnswerManager()
+
+    def get_user_vote(self, user):
+        votes = self.votes.filter(user=user)
+        if votes.count() > 0:
+            return votes[0]
+        else:
+            return None
+
+    def get_latest_revision(self):
+        return self.revisions.all()[0]
+
+    def get_question_title(self):
+        return self.question.title
+
+    def get_absolute_url(self):
+        return '%s%s#%s' % (reverse('question', args=[self.question.id]), self.question.title, self.id)
+
+    class Meta:
+        db_table = u'answer'
+
+    def __unicode__(self):
+        return self.html
+
+class AnswerRevision(models.Model):
+    """A revision of an Answer."""
+    answer     = models.ForeignKey(Answer, related_name='revisions')
+    revision   = models.PositiveIntegerField()
+    author     = models.ForeignKey(User, related_name='answer_revisions')
+    revised_at = models.DateTimeField()
+    summary    = models.CharField(max_length=300, blank=True)
+    text       = models.TextField()
+
+    def get_absolute_url(self):
+        return '/answers/%s/revisions' % (self.answer.id)
+
+    def get_question_title(self):
+        return self.answer.question.title
+
+    class Meta:
+        db_table = u'answer_revision'
+        ordering = ('-revision',)
+
+    def save(self, **kwargs):
+        """Looks up the next available revision number if not set."""
+        if not self.revision:
+            self.revision = AnswerRevision.objects.filter(
+                answer=self.answer).values_list('revision',
+                                                flat=True)[0] + 1
+        super(AnswerRevision, self).save(**kwargs)
+
+class FavoriteQuestion(models.Model):
+    """A favorite Question of a User."""
+    question      = models.ForeignKey(Question)
+    user          = models.ForeignKey(User, related_name='user_favorite_questions')
+    added_at = models.DateTimeField(default=datetime.datetime.now)
+    class Meta:
+        db_table = u'favorite_question'
+    def __unicode__(self):
+        return '[%s] favorited at %s' %(self.user, self.added_at)
+
+class Badge(models.Model):
+    """Awarded for notable actions performed on the site by Users."""
+    GOLD = 1
+    SILVER = 2
+    BRONZE = 3
+    TYPE_CHOICES = (
+        (GOLD,   _('gold')),
+        (SILVER, _('silver')),
+        (BRONZE, _('bronze')),
+    )
+
+    name        = models.CharField(max_length=50)
+    type        = models.SmallIntegerField(choices=TYPE_CHOICES)
+    slug        = models.SlugField(max_length=50, blank=True)
+    description = models.CharField(max_length=300)
+    multiple    = models.BooleanField(default=False)
+    # Denormalised data
+    awarded_count = models.PositiveIntegerField(default=0)
+
+    class Meta:
+        db_table = u'badge'
+        ordering = ('name',)
+        unique_together = ('name', 'type')
+
+    def __unicode__(self):
+        return u'%s: %s' % (self.get_type_display(), self.name)
+
+    def save(self, **kwargs):
+        if not self.slug:
+            self.slug = self.name#slugify(self.name)
+        super(Badge, self).save(**kwargs)
+
+    def get_absolute_url(self):
+        return '%s%s/' % (reverse('badge', args=[self.id]), self.slug)
+
+class Award(models.Model):
+    """The awarding of a Badge to a User."""
+    user       = models.ForeignKey(User, related_name='award_user')
+    badge      = models.ForeignKey(Badge, related_name='award_badge')
+    content_type   = models.ForeignKey(ContentType)
+    object_id      = models.PositiveIntegerField()
+    content_object = generic.GenericForeignKey('content_type', 'object_id')
+    awarded_at = models.DateTimeField(default=datetime.datetime.now)
+    notified   = models.BooleanField(default=False)
+    objects = AwardManager()
+    
+    def __unicode__(self):
+        return u'[%s] is awarded a badge [%s] at %s' % (self.user.username, self.badge.name, self.awarded_at)
+
+    class Meta:
+        db_table = u'award'
+
+class Repute(models.Model):
+    """The reputation histories for user"""
+    user     = models.ForeignKey(User)
+    positive = models.SmallIntegerField(default=0)
+    negative = models.SmallIntegerField(default=0)
+    question = models.ForeignKey(Question)
+    reputed_at = models.DateTimeField(default=datetime.datetime.now)
+    reputation_type = models.SmallIntegerField(choices=TYPE_REPUTATION)
+    reputation = models.IntegerField(default=1)
+    objects = ReputeManager()
+
+    def __unicode__(self):
+        return u'[%s]\' reputation changed at %s' % (self.user.username, self.reputed_at)
+
+    class Meta:
+        db_table = u'repute'
+
+class Activity(models.Model):
+    """
+    We keep some history data for user activities
+    """
+    user = models.ForeignKey(User)
+    activity_type = models.SmallIntegerField(choices=TYPE_ACTIVITY)
+    active_at = models.DateTimeField(default=datetime.datetime.now)
+    content_type   = models.ForeignKey(ContentType)
+    object_id      = models.PositiveIntegerField()
+    content_object = generic.GenericForeignKey('content_type', 'object_id')
+    is_auditted    = models.BooleanField(default=False)
+
+    def __unicode__(self):
+        return u'[%s] was active at %s' % (self.user.username, self.active_at)
+
+    class Meta:
+        db_table = u'activity'
+
+class Book(models.Model):
+    """
+    Model for book info
+    """
+    user = models.ForeignKey(User)
+    title = models.CharField(max_length=255)
+    short_name = models.CharField(max_length=255)
+    author = models.CharField(max_length=255)
+    price = models.DecimalField(max_digits=6, decimal_places=2)
+    pages = models.SmallIntegerField()
+    published_at = models.DateTimeField()
+    publication = models.CharField(max_length=255)
+    cover_img = models.CharField(max_length=255)
+    tagnames = models.CharField(max_length=125)
+    added_at = models.DateTimeField()
+    last_edited_at = models.DateTimeField()
+    questions = models.ManyToManyField(Question, related_name='book', db_table='book_question')
+    
+    def get_absolute_url(self):
+        return '%s' % reverse('book', args=[self.short_name])
+        
+    def __unicode__(self):
+        return self.title
+    class Meta:
+        db_table = u'book'
+
+class BookAuthorInfo(models.Model):
+    """
+    Model for book author info
+    """
+    user = models.ForeignKey(User)
+    book = models.ForeignKey(Book)
+    blog_url = models.CharField(max_length=255)
+    added_at = models.DateTimeField()
+    last_edited_at = models.DateTimeField()
+    
+    class Meta:
+        db_table = u'book_author_info'
+    
+class BookAuthorRss(models.Model):
+    """
+    Model for book author blog rss
+    """
+    user = models.ForeignKey(User)
+    book = models.ForeignKey(Book)
+    title = models.CharField(max_length=255)
+    url = models.CharField(max_length=255)
+    rss_created_at = models.DateTimeField()
+    added_at = models.DateTimeField()
+    
+    class Meta:
+        db_table = u'book_author_rss'
+
+# User extend properties
+QUESTIONS_PER_PAGE_CHOICES = (
+   (10, u'10'),
+   (30, u'30'),
+   (50, u'50'),
+)
+
+User.add_to_class('reputation', models.PositiveIntegerField(default=1))
+User.add_to_class('gravatar', models.CharField(max_length=32))
+User.add_to_class('favorite_questions',
+                  models.ManyToManyField(Question, through=FavoriteQuestion,
+                                         related_name='favorited_by'))
+User.add_to_class('badges', models.ManyToManyField(Badge, through=Award,
+                                                   related_name='awarded_to'))
+User.add_to_class('gold', models.SmallIntegerField(default=0))
+User.add_to_class('silver', models.SmallIntegerField(default=0))
+User.add_to_class('bronze', models.SmallIntegerField(default=0))
+User.add_to_class('questions_per_page',
+                  models.SmallIntegerField(choices=QUESTIONS_PER_PAGE_CHOICES, default=10))
+User.add_to_class('last_seen',
+                  models.DateTimeField(default=datetime.datetime.now))
+User.add_to_class('real_name', models.CharField(max_length=100, blank=True))
+User.add_to_class('website', models.URLField(max_length=200, blank=True))
+User.add_to_class('location', models.CharField(max_length=100, blank=True))
+User.add_to_class('date_of_birth', models.DateField(null=True, blank=True))
+User.add_to_class('about', models.TextField(blank=True))
+
+# custom signal
+tags_updated = django.dispatch.Signal(providing_args=["question"])
+edit_question_or_answer = django.dispatch.Signal(providing_args=["instance", "modified_by"])
+delete_post_or_answer = django.dispatch.Signal(providing_args=["instance", "deleted_by"])
+mark_offensive = django.dispatch.Signal(providing_args=["instance", "mark_by"])
+user_updated = django.dispatch.Signal(providing_args=["instance", "updated_by"])
+def get_messages(self):
+        messages = []
+        for m in self.message_set.all():
+            messages.append(m.message)
+        return messages
+
+def delete_messages(self):
+    self.message_set.all().delete()
+
+def get_profile_url(self):
+    """Returns the URL for this User's profile."""
+    return '%s%s/' % (reverse('user', args=[self.id]), self.username)
+User.add_to_class('get_profile_url', get_profile_url)
+User.add_to_class('get_messages', get_messages)
+User.add_to_class('delete_messages', delete_messages)
+
+def calculate_gravatar_hash(instance, **kwargs):
+    """Calculates a User's gravatar hash from their email address."""
+    if kwargs.get('raw', False):
+        return
+    instance.gravatar = hashlib.md5(instance.email).hexdigest()
+
+def record_ask_event(instance, created, **kwargs):
+    if created:
+        activity = Activity(user=instance.author, active_at=instance.added_at, content_object=instance, activity_type=TYPE_ACTIVITY_ASK_QUESTION)
+        activity.save()
+
+def record_answer_event(instance, created, **kwargs):
+    if created:
+        activity = Activity(user=instance.author, active_at=instance.added_at, content_object=instance, activity_type=TYPE_ACTIVITY_ANSWER)
+        activity.save()
+
+def record_comment_event(instance, created, **kwargs):
+    if created:
+        from django.contrib.contenttypes.models import ContentType
+        question_type = ContentType.objects.get_for_model(Question)
+        question_type_id = question_type.id
+        type = TYPE_ACTIVITY_COMMENT_QUESTION if instance.content_type_id == question_type_id else TYPE_ACTIVITY_COMMENT_ANSWER
+        activity = Activity(user=instance.user, active_at=instance.added_at, content_object=instance, activity_type=type)
+        activity.save()
+
+def record_revision_question_event(instance, created, **kwargs):
+    if created and instance.revision <> 1:
+        activity = Activity(user=instance.author, active_at=instance.revised_at, content_object=instance, activity_type=TYPE_ACTIVITY_UPDATE_QUESTION)
+        activity.save()
+
+def record_revision_answer_event(instance, created, **kwargs):
+    if created and instance.revision <> 1:
+        activity = Activity(user=instance.author, active_at=instance.revised_at, content_object=instance, activity_type=TYPE_ACTIVITY_UPDATE_ANSWER)
+        activity.save()
+
+def record_award_event(instance, created, **kwargs):
+    """
+    After we awarded a badge to user, we need to record this activity and notify user.
+    We also recaculate awarded_count of this badge and user information.
+    """
+    if created:
+        activity = Activity(user=instance.user, active_at=instance.awarded_at, content_object=instance,
+            activity_type=TYPE_ACTIVITY_PRIZE)
+        activity.save()
+
+        instance.badge.awarded_count += 1
+        instance.badge.save()
+
+        if instance.badge.type == Badge.GOLD:
+            instance.user.gold += 1
+        if instance.badge.type == Badge.SILVER:
+            instance.user.silver += 1
+        if instance.badge.type == Badge.BRONZE:
+            instance.user.bronze += 1
+        instance.user.save()
+
+def notify_award_message(instance, created, **kwargs):
+    """
+    Notify users when they have been awarded badges by using Django message.
+    """
+    if created:
+        user = instance.user
+        user.message_set.create(message=u"%s" % instance.badge.name)
+
+def record_answer_accepted(instance, created, **kwargs):
+    """
+    when answer is accepted, we record this for question author - who accepted it.
+    """
+    if not created and instance.accepted:
+        activity = Activity(user=instance.question.author, active_at=datetime.datetime.now(), \
+            content_object=instance, activity_type=TYPE_ACTIVITY_MARK_ANSWER)
+        activity.save()
+
+def update_last_seen(instance, created, **kwargs):
+    """
+    when user has activities, we update 'last_seen' time stamp for him
+    """
+    user = instance.user
+    user.last_seen = datetime.datetime.now()
+    user.save()
+
+def record_vote(instance, created, **kwargs):
+    """
+    when user have voted
+    """
+    if created:
+        if instance.vote == 1:
+            vote_type = TYPE_ACTIVITY_VOTE_UP
+        else:
+            vote_type = TYPE_ACTIVITY_VOTE_DOWN
+
+        activity = Activity(user=instance.user, active_at=instance.voted_at, content_object=instance, activity_type=vote_type)
+        activity.save()
+
+def record_cancel_vote(instance, **kwargs):
+    """
+    when user canceled vote, the vote will be deleted.
+    """
+    activity = Activity(user=instance.user, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_CANCEL_VOTE)
+    activity.save()
+
+def record_delete_question(instance, delete_by, **kwargs):
+    """
+    when user deleted the question
+    """
+    if instance.__class__ == "Question":
+        activity_type = TYPE_ACTIVITY_DELETE_QUESTION
+    else:
+        activity_type = TYPE_ACTIVITY_DELETE_ANSWER
+
+    activity = Activity(user=delete_by, active_at=datetime.datetime.now(), content_object=instance, activity_type=activity_type)
+    activity.save()
+
+def record_mark_offensive(instance, mark_by, **kwargs):
+    activity = Activity(user=mark_by, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_MARK_OFFENSIVE)
+    activity.save()
+
+def record_update_tags(question, **kwargs):
+    """
+    when user updated tags of the question
+    """
+    activity = Activity(user=question.author, active_at=datetime.datetime.now(), content_object=question, activity_type=TYPE_ACTIVITY_UPDATE_TAGS)
+    activity.save()
+
+def record_favorite_question(instance, created, **kwargs):
+    """
+    when user add the question in him favorite questions list.
+    """
+    if created:
+        activity = Activity(user=instance.user, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_FAVORITE)
+        activity.save()
+
+def record_user_full_updated(instance, **kwargs):
+    activity = Activity(user=instance, active_at=datetime.datetime.now(), content_object=instance, activity_type=TYPE_ACTIVITY_USER_FULL_UPDATED)
+    activity.save()
+
+#signal for User modle save changes
+pre_save.connect(calculate_gravatar_hash, sender=User)
+post_save.connect(record_ask_event, sender=Question)
+post_save.connect(record_answer_event, sender=Answer)
+post_save.connect(record_comment_event, sender=Comment)
+post_save.connect(record_revision_question_event, sender=QuestionRevision)
+post_save.connect(record_revision_answer_event, sender=AnswerRevision)
+post_save.connect(record_award_event, sender=Award)
+post_save.connect(notify_award_message, sender=Award)
+post_save.connect(record_answer_accepted, sender=Answer)
+post_save.connect(update_last_seen, sender=Activity)
+post_save.connect(record_vote, sender=Vote)
+post_delete.connect(record_cancel_vote, sender=Vote)
+delete_post_or_answer.connect(record_delete_question, sender=Question)
+delete_post_or_answer.connect(record_delete_question, sender=Answer)
+mark_offensive.connect(record_mark_offensive, sender=Question)
+mark_offensive.connect(record_mark_offensive, sender=Answer)
+tags_updated.connect(record_update_tags, sender=Question)
+post_save.connect(record_favorite_question, sender=FavoriteQuestion)
+user_updated.connect(record_user_full_updated, sender=User)