app.py

import os
import sys

from flask import Flask, render_template, request, url_for, redirect, flash
from flask_sqlalchemy import SQLAlchemy

import click

from werkzeug.security import generate_password_hash, check_password_hash

from flask_login import UserMixin

from flask_login import login_user, current_user

from flask_login import login_required, logout_user

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////' + os.path.join(app.root_path, 'data.db')
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False  # 关闭对模型修改的监控
app.config['SECRET_KEY'] = 'dev'

db = SQLAlchemy(app)

@app.route('/logout')
@login_required  # 用于视图保护，后面会详细介绍
def logout():
	logout_user()  # 登出用户
	flash('Goodbye.')
	return redirect(url_for('index'))  # 重定向回首页

@app.cli.command()  # 注册为命令
@click.option('--drop', is_flag=True, help='Create after drop.')  # 设置选项
def initdb(drop):
	"""Initialize the database."""
	if drop:  # 判断是否输入了选项
		db.drop_all()
	db.create_all()
	click.echo('Initialized database.')  # 输出提示信息

class User(db.Model, UserMixin):
	id = db.Column(db.Integer, primary_key=True)  # 主键
	name = db.Column(db.String(20))  # 名字
	username = db.Column(db.String(20))
	password_hash = db.Column(db.String(128))

	def set_password(self, password):  # 用来设置密码的方法，接受密码作为参数
		self.password_hash = generate_password_hash(password)  # 将生成的密码保持到对应字段

	def validate_password(self, password):  # 用于验证密码的方法，接受密码作为参数
		return check_password_hash(self.password_hash, password)  # 返回布尔值

class Movie(db.Model):  # 表名将会是 movie
	id = db.Column(db.Integer, primary_key=True)  # 主键
	title = db.Column(db.String(60))  # 电影标题
	year = db.Column(db.String(4))  # 电影年份

@app.cli.command()
def forge():
	db.create_all()

	name = 'Grey Li'
	movies = [
		{'title': 'My Neighbor Totoro', 'year': '1988'},
		{'title': 'Dead Poets Society', 'year': '1989'},
		{'title': 'A Perfect World', 'year': '1993'},
		{'title': 'Leon', 'year': '1994'},
		{'title': 'Mahjong', 'year': '1996'},
		{'title': 'Swallowtail Butterfly', 'year': '1996'},
		{'title': 'King of Comedy', 'year': '1999'},
		{'title': 'Devils on the Doorstep', 'year': '1999'},
		{'title': 'WALL-E', 'year': '2008'},
		{'title': 'The Pork of Music', 'year': '2012'},
	]

	user = User(name=name)
	db.session.add(user)
	for m in movies:
		movie = Movie(title=m['title'], year=m['year'])
		db.session.add(movie)

	db.session.commit()
	click.echo('Done.')

@app.route('/', methods=['GET', 'POST'])
def index():
	if request.method == 'POST':
		if not current_user.is_authenticated:  # 如果当前用户未认证
			return redirect(url_for('index'))
		title = request.form.get('title')
		year = request.form.get('year')
		if not title or not year or len(year) > 4 or len(title) > 60:
			flash('Invalid input.')
			return redirect(url_for('index'))
		movie = Movie(title=title, year=year)
		db.session.add(movie)
		db.session.commit()
		flash('Item created.')
		return redirect(url_for('index'))
	user = User.query.first()
	movies = Movie.query.all()
	return render_template('index.html', user=user, movies=movies)

@app.errorhandler(404)
def page_not_found(e):
	return render_template('404.html'), 404

@app.context_processor
def inject_user():
	user = User.query.first()
	return dict(user=user)

@app.route('/movie/edit/<int:movie_id>', methods=['GET', 'POST'])
@login_required
def edit(movie_id):
	movie = Movie.query.get_or_404(movie_id)

	if request.method == 'POST':  # 处理编辑表单的提交请求
		title = request.form['title']
		year = request.form['year']

		if not title or not year or len(year) > 4 or len(title) > 60:
			flash('Invalid input.')
			return redirect(url_for('edit', movie_id=movie_id))  # 重定向回对应的编辑页面

		movie.title = title  # 更新标题
		movie.year = year  # 更新年份
		db.session.commit()  # 提交数据库会话
		flash('Item updated.')
		return redirect(url_for('index'))  # 重定向回主页

	return render_template('edit.html', movie=movie)  # 传入被编辑的电影记录

@app.route('/movie/delete/<int:movie_id>', methods=['POST'])  # 限定只接受 POST 请求
@login_required
def delete(movie_id):
	movie = Movie.query.get_or_404(movie_id)  # 获取电影记录
	db.session.delete(movie)  # 删除对应的记录
	db.session.commit()  # 提交数据库会话
	flash('Item deleted.')
	return redirect(url_for('index'))  # 重定向回主页

@app.cli.command()
@click.option('--username', prompt=True, help='The username used to login.')
@click.option('--password', prompt=True, hide_input=True, confirmation_prompt=True, help='The password used to login.')
def admin(username, password):
	"""Create user."""
	db.create_all()

	user = User.query.first()
	if user is not None:
		click.echo('Updating user...')
		user.username = username
		user.set_password(password)  # 设置密码
	else:
		click.echo('Creating user...')
		user = User(username=username, name='Admin')
		user.set_password(password)  # 设置密码
		db.session.add(user)

	db.session.commit()  # 提交数据库会话
	click.echo('Done.')

from flask_login import LoginManager

login_manager = LoginManager(app)  # 实例化扩展类

login_manager.login_view = 'login'

@login_manager.user_loader
def load_user(user_id):  # 创建用户加载回调函数，接受用户 ID 作为参数
	user = User.query.get(int(user_id))  # 用 ID 作为 User 模型的主键查询对应的用户
	return user  # 返回用户对象

@app.route('/login', methods=['GET', 'POST'])
def login():
	if request.method == 'POST':
		username = request.form['username']
		password = request.form['password']

		if not username or not password:
			flash('Invalid input.')
			return redirect(url_for('login'))

		user = User.query.first()
		# 验证用户名和密码是否一致
		if username == user.username and user.validate_password(password):
			login_user(user)  # 登入用户
			flash('Login success.')
			return redirect(url_for('index'))  # 重定向到主页

		flash('Invalid username or password.')  # 如果验证失败，显示错误消息
		return redirect(url_for('login'))  # 重定向回登录页面

	return render_template('login.html')

@app.route('/settings', methods=['GET', 'POST'])
@login_required
def settings():
	if request.method == 'POST':
		name = request.form['name']

		if not name or len(name) > 20:
			flash('Invalid input.')
			return redirect(url_for('settings'))

		current_user.name = name
		# current_user 会返回当前登录用户的数据库记录对象
		# 等同于下面的用法
		# user = User.query.first()
		# user.name = name
		db.session.commit()
		flash('Settings updated.')
		return redirect(url_for('index'))

	return render_template('settings.html')