你的第一个博客-第一弹

使用 Flask 开发博客

Flask 是一个轻量级的 Web 框架，适合小型应用和学习项目。我们将通过 Flask 开发一个简单的博客系统，支持用户注册、登录、发布文章等功能。

步骤：

安装 Flask 和其他必要库：

在开发博客之前，首先需要安装 Flask。可以使用 pip 安装 Flask 和其他依赖：
```
pip install Flask Flask-SQLAlchemy Flask-WTF Flask-Login email-validator 
```

项目结构：

项目结构如下：

/blog/templatesbase.htmlcreate_post.htmledit_post.htmlindex.htmllayout.htmllogin.htmlregister.htmlpost.html/static/cssstyle.cssapp.pymodels.pyforms.py

创建数据库模型 (models.py)：

使用 Flask 的 SQLAlchemy 扩展来进行数据库操作。我们首先定义用户和文章的数据库模型。

python"># models.py
from flask_sqlalchemy import SQLAlchemy
from datetime import datetime  # 导入 datetime
from flask_login import UserMixindb = SQLAlchemy()class User(UserMixin, db.Model):id = db.Column(db.Integer, primary_key=True)username = db.Column(db.String(80), unique=True, nullable=False)email = db.Column(db.String(120), unique=True, nullable=False)password = db.Column(db.String(120), nullable=False)date_registered = db.Column(db.DateTime, default=datetime.utcnow)is_active = db.Column(db.Boolean, default=True)  # 默认值设置为True，表示用户激活def get_id(self):return str(self.id)  # 或者返回其他唯一标识符，如 email 等posts = db.relationship('Post', back_populates='user', lazy=True)class Post(db.Model):id = db.Column(db.Integer, primary_key=True)title = db.Column(db.String(100), nullable=False)content = db.Column(db.Text, nullable=False)date_posted = db.Column(db.DateTime, default=datetime.utcnow)# 外键关联用户表user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)# 修改 backref 名称，避免与 User 模型中的属性冲突user = db.relationship('User', back_populates='posts')def __init__(self, title, content, user):self.title = titleself.content = contentself.user = user  # author 参数应该作为 user

创建 Flask 应用 (app.py)：

在 app.py 中初始化 Flask 应用，配置数据库，处理用户请求和路由。

python"># app.py
from flask import Flask, render_template, url_for, redirect, request, flash
from models import db, User, Post
from flask_login import LoginManager, login_user, login_required, current_user, logout_user
from forms import RegistrationForm, LoginForm, PostForm
from datetime import datetimeapp = Flask(__name__)
app.config['SECRET_KEY'] = '123456'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///site.db'
db.init_app(app)with app.app_context():db.create_all()  # 创建数据库表login_manager = LoginManager(app)
login_manager.login_view = 'login'@login_manager.user_loader
def load_user(user_id):return db.session.get(User, int(user_id))@app.route('/')
def index():posts = Post.query.all()print(current_user.is_authenticated)return render_template('index.html', posts=posts)@app.route('/register', methods=['GET', 'POST'])
def register():form = RegistrationForm()if form.validate_on_submit():user = User(username=form.username.data, email=form.email.data, password=form.password.data)db.session.add(user)db.session.commit()flash('Your account has been created!', 'success')return redirect(url_for('login'))return render_template('register.html', form=form)@app.route('/login', methods=['GET', 'POST'])
def login():form = LoginForm()if form.validate_on_submit():user = User.query.filter_by(username=form.username.data).first()if user and user.password == form.password.data:login_user(user)return redirect(url_for('index'))else:flash('Login Unsuccessful. Please check username and password', 'danger')return render_template('login.html', form=form)@app.route('/logout')
def logout():logout_user()return redirect(url_for('index'))@app.route('/post/new', methods=['GET', 'POST'])
@login_required
def new_post():form = PostForm()if form.validate_on_submit():post = Post(title=form.title.data, content=form.content.data, user=current_user)db.session.add(post)db.session.commit()flash('Your post has been created!', 'success')return redirect(url_for('index'))return render_template('create_post.html', title='New Post', form=form)@app.route("/post/<int:post_id>")
def post(post_id):post = Post.query.get_or_404(post_id)return render_template('post.html', post=post)@app.route('/post/edit/<int:post_id>', methods=['GET', 'POST'])
@login_required
def edit_post(post_id):post = Post.query.get_or_404(post_id)# 确保只能编辑自己的博客if post.user != current_user:flash('You cannot edit this post.', 'danger')return redirect(url_for('index'))form = PostForm()if form.validate_on_submit():post.title = form.title.datapost.content = form.content.datadb.session.commit()flash('Your post has been updated!', 'success')return redirect(url_for('index'))# 使用现有的博客数据填充表单elif request.method == 'GET':form.title.data = post.titleform.content.data = post.contentreturn render_template('edit_post.html', title='Edit Post', form=form, post=post)@app.route("/post/delete/<int:post_id>", methods=["Get", `"POST"])
def delete_post(post_id):post = Post.query.get_or_404(post_id)db.session.delete(post)db.session.commit()flash("Post has been deleted!", "success")return redirect(url_for('index'))  # 或者返回其他页面if __name__ == '__main__':app.run(debug=True)

创建表单 (forms.py)：

使用 Flask-WTF 扩展来创建用户注册、登录和文章发布的表单。

python"># forms.py
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, TextAreaField
from wtforms.validators import DataRequired, Length, Email, EqualToclass RegistrationForm(FlaskForm):username = StringField('Username', validators=[DataRequired(), Length(min=2, max=20)])email = StringField('Email', validators=[DataRequired(), Email()])password = PasswordField('Password', validators=[DataRequired()])confirm_password = PasswordField('Confirm Password', validators=[DataRequired(), EqualTo('password')])class LoginForm(FlaskForm):username = StringField('Username', validators=[DataRequired()])password = PasswordField('Password', validators=[DataRequired()])class PostForm(FlaskForm):title = StringField('Title', validators=[DataRequired()])content = TextAreaField('Content', validators=[DataRequired()])

创建模板 (HTML)：

在 templates 文件夹中，创建 HTML 模板来展示博客页面。

<!-- index.html -->
{% extends 'base.html' %}
{% block content %}
<h1>Blog Posts</h1>
<ul>{% for post in posts %}<li><h2>{{ post.title }}</h2><p>{{ post.content }}</p><p><small>Posted on {{ post.date_posted }}</small></p></li>{% endfor %}
</ul>
{% endblock %}