1.装饰器装饰多个视图函数出现的问题
代码实例:
from flask import Flask, request, render_template, session, redirect
app = Flask(__name__)
app.secret_key = "$%@&!**" # $%@&!**是加密字符串,可随意设置
@app.route("/login", methods=["GET", "POST"])
def login():
if request.method == "GET":
return render_template("login.html")
else:
session["username"] = request.form.get("username")
return redirect("/detail")
# 自定义装饰器
def outer(func):
def inner(*args, **kwargs):
if session.get("username"):
ret = func(*args, **kwargs)
return ret
else:
return redirect("/login")
return inner
@app.route("/detail", methods=["GET", ])
@outer
def detail():
return render_template("detail.html")
@app.route("/detail2", methods=["GET", ])
@outer
def detail2():
return "this is detail2"
if __name__ == '__main__':
app.run(debug=True)
"""
执行结果:
AssertionError: View function mapping is overwriting an existing endpoint function: inner
结论: 用装饰器装饰多个视图函数会抛出异常, 原因是多次出现了innner函数,产生覆盖现象
"""
2.使用装饰器修复技术解决该问题
from flask import Flask, request, render_template, session, redirect
from functools import wraps
app = Flask(__name__)
app.secret_key = "~!@#$%^"
@app.route("/login", methods=["GET", "POST"])
def login():
if request.method == "GET":
return render_template("login.html")
else:
session["username"] = request.form.get("username")
return redirect("/detail")
# 自定义装饰器
def outer(func):
@wraps(func) # 装饰器修复技术
def inner(*args, **kwargs):
if session.get("username"):
ret = func(*args, **kwargs)
return ret
else:
return redirect("/login")
return inner
@app.route("/detail", methods=["GET", ])
@outer
def detail():
return "this is detail"
@app.route("/detail2", methods=["GET", ])
@outer
def detail2():
return "this is detail2"
if __name__ == '__main__':
app.run()