Flask（八）

一、钩子函数与上下文处理器

from flask import Flask,Response,request,session,render_template,g
import config
from exts import db,mail
from blueprints import qa_bp
from blueprints import user_bp
from flask_migrate import Migrate
from models import UserModel

app = Flask(__name__)
app.config.from_object(config)
db.init_app(app)
mail.init_app(app)

migrate=Migrate(app,db)

app.register_blueprint(qa_bp)
app.register_blueprint(user_bp)

#钩子函数
@app.before_request
def before_request():
    user_id=session.get("user_id")
    if user_id:
        try:
            user = UserModel.query.get(user_id)
            #给g绑定一个叫做user的变量，它的值是user这个变量
            #setattr(g,"user",user)
            g.user=user
        except:
            g.user=None

#请求来了-> before_request->视图函数->视图函数中返回的模板->context_processor

#上下文处理器
@app.context_processor
def context_processor():
    if hasattr(g,"user"):
        return {"user":g.user}
    else:
        return {}


if __name__ =='__main__':
    app.run(debug=True)

    
    
    
    
  {% block head %} {% endblock %}



  

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      {% if user %}
       

       {{user.username}}
       
       

        退出登录
      
       {% else %}
       

        登录 
      
      

        注册
      
       {% endif %}
    
    
  

{% block body %}{% endblock %}

登录后会是这样的页面：

而没登陆是这样的：

 

二、退出登录功能

import random
import string

from flask import Blueprint,render_template,request,redirect,url_for,jsonify,session,flash
from exts import mail,db
from flask_mail import Message
from models import EmailCaptchaModel,UserModel
from datetime import datetime
from .forms import  RegisterForm
from werkzeug.security import generate_password_hash,check_password_hash

bp=Blueprint("user",__name__,url_prefix="/user")

#实现登录功能
@bp.route("/login",method=['GET','POST'])
def login():
    if request.method=='GET':
        return render_template("login.html")
    else:
        form = LoginForm(request.form)
        if form.validate():
            email=form.email.data
            password=form.password.data
            user=UserModel.query.filter_by(email=email).first()
            if user and check_password_hash(user.password,password):
                session['user_id']=user.id
                return redirect("/")
            else:
                flash("邮箱和密码不匹配！")
                return redirect(url_for("user.login"))
        else:
            flash("邮箱或密码格式错误！")
            return redirect(url_for("user.login"))


@bp.route("/register",methods=['GET','POST'])
def register():
    if request.method =='GET':
        return render_template("register.html")
    else:
        form = RegisterForm(request.form)
        if form.validate():
            email = form.email.data
            username = form.username.data
            password = form.password.data

            hash_password=generate_password_hash(password)   #密码加密
            user = UserModel(email=email, username=username, password=password)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for("user.login"))
        else:
            return redirect(url_for("user.register"))

#退出登录
@bp.route("/logout")
def logout():
    #清除session中所有的数据
    session.clear()
    return redirect(url_for('user.login'))

@bp.route("/captcha",methods=['POST'])
def get_captcha():
    email=request.form.get("email")
    letter=string.ascii_letters+string.digits
    captcha="".join(random.sample(letter,4))
    if email:
        message = Message(
            subject='邮箱测试',
            recipients=['[email protected]'],
            body=f"您的注册验证码是：{captcha},请不要告诉任何人哦！"
        )
        mail.send(message)
        captcha_model=EmailCaptchaModel.query.filter_by(email=email).first()
        if captcha_model:
            captcha_model.captcha=captcha
            captcha_model.create_time=datetime.now()
            db.session.commit()
        else:
            captcha_model=EmailCaptchaModel(email=email,captcha=captcha)
            db.session.add(captcha_model)
            db.session.commit()
            #code:200。成功的，正常的请求
        return jsonify({"code":200})
    else:
        #code:400  客户端错误
        return jsonify({"code":400,"message":"请先传递邮箱！"})

    
    
    
    
  {% block head %} {% endblock %}



  

  问答
  
    
  
  

    

      

        首页 (current)
      
      

        发布问答
      
         

          

            
            搜索
         
    
    
     

      {% if user %}
       

       {{user.username}}
       
       

        退出登录
      
       {% else %}
       

        登录 
      
      

        注册
      
       {% endif %}
    
    
  

{% block body %}{% endblock %}