models.py

import datetime, re
from app import db, login_manager, bcrypt


def slugify(s):
    """Helper function which uses a regular expression to generate a string that can be used as URL."""
    return re.sub('[^\w]+', '-', s).lower()


entry_tags = db.Table('entry_tags',
                      db.Column('tag_id', db.Integer, db.ForeignKey('tag.id')),
                      db.Column('entry_id', db.Integer, db.ForeignKey('entry.id'))
                      )


@login_manager.user_loader
def _user_loader(user_id):
    return User.query.get(int(user_id))


class Entry(db.Model):
    """Model of blog entry. It can be saved as a draft or published. After deleting it stays in the database.
    It does have a title, body, time of creation and publication.
    It can be tagged."""

    STATUS_PUBLIC = 0
    STATUS_DRAFT = 1
    STATUS_DELETED = 2

    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(100))
    slug = db.Column(db.String(100), unique=True)
    body = db.Column(db.Text)
    status = db.Column(db.SmallInteger, default=STATUS_PUBLIC)
    created_timestamp = db.Column(db.DateTime, default=datetime.datetime.now)
    modified_timestamp = db.Column(db.DateTime, default=datetime.datetime.now, onupdate=datetime.datetime.now)
    author_id = db.Column(db.Integer, db.ForeignKey("user.id"))
    tags = db.relationship('Tag', secondary=entry_tags, lazy='dynamic', backref=db.backref('entries', lazy='dynamic'))

    def __init__(self, *args, **kwargs):
        super(Entry, self).__init__(*args, **kwargs)  # Call parent constructor.
        self.generate_slug()

    def generate_slug(self):
        self.slug = ''
        if self.title:
            self.slug = slugify(self.title)

    def __repr__(self):
        return '<Entry: {}>'.format(self.title)

    @property
    def tag_list(self):
        return ', '.join(tag.name for tag in self.tags)

    @property
    def tease(self):
        return self.body[:100]


class Tag(db.Model):
    """Model of a tag with which the entries can be connected."""
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64))
    slug = db.Column(db.String(64), unique=True)

    def __init__(self, *args, **kwargs):
        super(Tag, self).__init__(*args, **kwargs)
        self.slug = slugify(self.name)

    def __repr__(self):
        return '<Tag {}>'.format(self.name)


class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(64), unique=True)
    password_hash = db.Column(db.String(255))
    name = db.Column(db.String(64))
    slug = db.Column(db.String(64), unique=True)
    active = db.Column(db.Boolean, default=True)
    admin = db.Column(db.Boolean, default=False)
    created_timestamp = db.Column(db.DateTime, default=datetime.datetime.now)

    entries = db.relationship('Entry', backref='author', lazy='dynamic')

    def __init__(self, *args, **kwargs):
        super(User, self).__init__(*args, **kwargs)
        self.generate_slug()

    def generate_slug(self):
        if self.name:
            self.slug = slugify(self.name)

    # Flask-Login interface.
    def get_id(self):
        return str(self.id)

    def is_authenticated(self):
        return True

    def is_active(self):
        return self.active

    def is_anonymous(self):
        return False

    def is_admin(self):
        return self.admin

    @staticmethod
    def make_password(plaintext):
        return bcrypt.generate_password_hash(plaintext).decode('utf-8')

    def check_password(self, raw_password):
        return bcrypt.check_password_hash(self.password_hash, raw_password)

    @classmethod
    def create(cls, email, password, **kwargs):
        return cls(
            email=email,
            password_hash=cls.make_password(password),
            **kwargs)

    @staticmethod
    def authenticate(email, password):
        user = User.query.filter(User.email == email).first()
        if user and user.check_password(password):
            return user
        return False