Flask特殊装饰器-@app.before_request、@app.after_request、@app.errorhandler

#Flask特殊装饰器
#@app.before_request #请求进入视图函数之前
#@app.after_request  #请求结束返回响应客户端之前

    #正常  be1-be2-be3 -vf -af3-af2-af1
    #异常 be1-be2-af3-af2-af1

#重定义错误信息
#@app.errorhandler(4XX or 5XX) 错误处理，(4XX or 5XX)代表响应码


from flask import Flask,request,session,redirect,render_template,send_file
app = Flask(__name__)
app.secret_key='@HID*@#'


#
# def warp(fun):
#     def inner(*args,**kwargs):
#
#         if session.get("user"):
#             ret = fun(*args,**kwargs)
#         else:
#             return redirect("/login_se")
#         print("校验完成")
#
#         return ret
#     return inner


@app.before_request
def be1():
    print("我是be1")

@app.before_request
def be2():
    print("我是be2")
    if request.path == "/login_se":
        return None
    if session.get("user"):
        return None
    else:
        return redirect("/login_se")

@app.before_request
def be3():
    print("我是be3")



@app.after_request
def af1(res):
    print("af1")
    return res

@app.after_request
def af2(res):
    print("af2")
    return res

@app.after_request
def af3(res):
    print("af3")
    return res


@app.route("/login_se",methods=["GET","POST"])
def login_se():
    if request.method == 'GET':
        return render_template("login_new.html")
    else:
        session["user"]=request.form.get("username")
        return "登陆成功"


@app.route("/index")
def index():
    print("我是视图函数")
    return render_template("home.html")


@app.route("/index1")
def index1():
    return render_template("home.html")


@app.route("/index2")
def index2():
    return render_template("home.html")


@app.errorhandler(404)
def error404(ErrorMessgae):
    print(ErrorMessgae)
    # return f"你访问的{request.path}不存在"
    # return redirect("/login_se")
    return send_file("my_picture/111.png")

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