版权声明:FatPuffer https://blog.csdn.net/qq_42517220/article/details/88743922
请求钩子(hook),类似于Django中的中间件。
(1)before_first_request:在处理第一个
请求前运行
# coding:utf-8
from flask import Flask
app = Flask(__name__)
@app.route('/index')
def index():
print("index 被执行")
return "index page"
@app.before_first_request
def handle_before_first_request():
"""在第一次请求被被处理前执行"""
print("你要先通过我")
if __name__ == "__main__":
app.run(debug=True)
我们再次访问
(2)before_request:在每次请求前运行
# coding:utf-8
from flask import Flask
app = Flask(__name__)
@app.route('/index')
def index():
print("index 被执行")
return "index page"
@app.before_request
def handle_before_request():
"""在每次请求前都被执行"""
print("每次请求前都必须通过我才可以")
if __name__ == "__main__":
app.run(debug=True)
(3)after_request:如果没有未处理的异常抛出,在每次请求后运行,必须return
# coding:utf-8
from flask import Flask
app = Flask(__name__)
@app.route('/index')
def index():
print("index 被执行")
return "index page"
@app.after_request
def handle_after_request(response):
"""如果没出错,每次请求后都要通过我"""
print("如果没出错,每次请求后都要通过我")
return response
if __name__ == "__main__":
app.run(debug=True)
# coding:utf-8
from flask import Flask
app = Flask(__name__)
@app.route('/index')
def index():
print("index 被执行")
info = 100 / 0
return info
@app.after_request
def handle_after_request(response):
"""如果没出错,每次请求后都要通过我"""
print("如果没出错,每次请求后都要通过我")
if __name__ == "__main__":
app.run(debug=True)
(4)teardown_request:在每次请求后运行,即使有未处理的异常抛出(但必须在生产模式下),必须return
# coding:utf-8
from flask import Flask
app = Flask(__name__)
@app.route('/index')
def index():
print("index 被执行")
return "index page"
@app.teardown_request
def handle_teardown_request(response):
"""不管是否出错,每次请求后都要调用我"""
print("不管是否出错,每次请求后都要调用我")
return response
if __name__ == "__main__":
app.run(debug=True)
# coding:utf-8
from flask import Flask
app = Flask(__name__)
@app.route('/index')
def index():
print("index 被执行")
info = 100 / 0
return info
@app.teardown_request
def handle_teardown_request(response):
"""不管是否出错,每次请求后都要调用我"""
print("不管是否出错,每次请求后都要调用我")
return response
if __name__ == "__main__":
app.run()
以上请求钩子方法对全局
视图生效,那么我们如何对特定的视图处理函数进行定制?
针对指定视图处理函数定制请求钩子方法
通过request.path来区分请求路径进行定制
# coding:utf-8
from flask import Flask, url_for, request
app = Flask(__name__)
@app.route('/index')
def index():
print("index 被执行")
return "index page"
@app.route('/hello')
def hello():
print("hello 被执行")
return "hello page"
@app.teardown_request
def handle_teardown_request(response):
"""不管是否出错,每次请求后都要调用我"""
# 对多个视图做定制
# if path in [url_for("index"), url_for("register"), url_for("login")]:
# 对单个视图做定制
path = request.path
if path == url_for("index"):
print("不管是否出错,每次请求后都要调用我")
return response
if __name__ == "__main__":
app.run(debug=True)