Flask——特殊的装饰器

app.before_request

from flask import Flask,render_template,send_file,request,redirect,session

app = Flask(__name__,template_folder="templates")
app.secret_key="henry"

@app.before_request 
def auth():
    # 白名单放行
    if request.path == "/login":
        return None
    # 判断是否是登录用户
    if session.get("username"):
        return None
    else:
        # 如果不是登录页面就会跳转到登录页面
        return redirect("login")

@app.route("/login",methods=["GET","POST"])
def login():
    if request.method=="GET":
        return render_template("login.html")
    username = request.form.get("username")
    password = request.form.get("password")
    # 判断用户名和密码是否正确
    if username=="henry" and password=="123456":
        # 登录成功后设置session
        session["username"] = username
        # 访问home页面之前会先走before_request装饰器,每个请求都会完整的走一遍before_request装饰器
        return redirect("home")
    else:
        return "用户名或密码错误"

@app.route('/home')
def home():
    return "home"

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

app.before_after

@app.after_request
def foot_log(environ):
    if request.path != "/login":
        print("有客人访问了",request.path)
    return environ