import os
from jinja2 import escape
from flask import Flask, make_response,request, redirect,url_for,abort,session,jsonify
from urllib.parse import urlparse, urljoin
from jinja2.utils import generate_lorem_ipsum
app = Flask(__name__)
app.secret_key = os.getenv('SECRET_KEY', ' secret string')
# 从查询字段和cookies 获取名字
@app.route('/')
@app.route('/hello')
def hello():
name = request.args.get('name')
if name is None:
name = request.cookies.get('name', 'Human')
response = '<h1>Hello %s!</h1>' % escape(name)
# return different response according to the user's authentication status
if 'logged_in' in session:
response += '[Authenticated]'
else:
response += '[Not Authenticated]'
return response
# 重定向例子
@app.route('/hi')
def hi():
return redirect(url_for('hello')) # url_for表示程序内路径，去找hello函数
@app.route('/goback/<int:year>')
def go_back(year):
return "<h1>welcome to %d"%(2018-year)
@app.route('/colors/<any(blue, white, red):color>')
def three_color(color):
return "<p>Love is patient and kind. Love is not jealous or boastful or pround or rude.</p>"
@app.route('/brew/<drink>')
def reapot(drink):
if drink == 'coffee':
abort(418)
else:
return 'a drink of tea'
@app.route('/404')
def not_found():
abort(404)
# 返回不同的数据类型(MIME类型)
@app.route('/note', defaults={'content_type': 'text'})
@app.route('/note/<content_type>')
def note(content_type):
content_type = content_type.lower()
if content_type == 'text':
body = '''Note
to: Peter
from: Jane
heading: Reminder
body: Don't forget the party!
'''
response = make_response(body)
response.mimetype = 'text/plain'
elif content_type == 'html':
body = '''<!DOCTYPE html>
<html>
<head></head>
<body>
<h1>Note</h1>
<p>to: Peter</p>
<p>from: Jane</p>
<p>heading: Reminder</p>
<p>body: <strong>Don't forget the party!</strong></p>
</body>
</html>
'''
response = make_response(body)
response.mimetype = 'text/html'
elif content_type == 'xml':
body = '''<?xml version="1.0" encoding="UTF-8"?>
<note>
<to>Peter</to>
<from>Jane</from>
<heading>Reminder</heading>
<body>Don't forget the party!</body>
</note>
'''
response = make_response(body)
response.mimetype = 'application/xml'
elif content_type == 'json':
body = {"note": {
"to": "Peter",
"from": "Jane",
"heading": "Remider",
"body": "Don't forget the party!"
}
}
response = jsonify(body)
# equal to:
# response = make_response(json.dumps(body))
# response.mimetype = "application/json"
else:
abort(400)
return response
# 设置cookie
@app.route('/set/<name>')
def set_cookies(name):
response = make_response(redirect(url_for('hello')))
response.set_cookie('name', name)
return response
# 实现用户登录 2-5
@app.route('/login')
def login():
session['logged_in'] = True
return redirect(url_for('hello'))
# 保护视图
@app.route('/admin')
def admin():
if 'logged_in' not in session:
abort(403)
return 'welcome to admin page'
@app.route('/logout')
def logout():
if 'logged_in' in session:
session.pop('logged_in')
return redirect(url_for('hello'))
# 返回上一个页面
@app.route('/foo')
def foo():
return '<h1>Foo page</h1><a href="%s"> Do something and redirect</a>'\
% url_for('do_something', next=request.full_path)
@app.route('/bar')
def bar():
return '<h1>Bar page</h1> <a href="%s"> Do something and redicrect</a>'\
% url_for('do_something', next=request.full_path)
@app.route('/do-something')
def do_something():
# do something
return redirect_back()
def is_safe_url(target):
ref_url = urlparse(request.host_url) # 获取主机url
test_url = urlparse(urljoin(request.host_url, target))
return test_url.scheme in ('http', 'https') and \
ref_url.netloc == test_url.netloc
def redirect_back(default='hello', **kwargs):
for target in request.args.get('next'), request.referrer:
if not target:
continue
if is_safe_url(target):
return redirect(target)
return redirect(url_for('default', **kwargs))
# AJAX 点击按钮加载更多文本
@app.route('/post')
def show_post():
post_body = generate_lorem_ipsum(n=2) # 生成两段随即文本
return '''
<h1>A very long post</h1>
<div class="body">%s</div>
<button id="load">Load More</button>
<script src="http://code.jquery.com/jquery-3.3.1.min.js"></script>
<script type="text/javascript">
$(function(){
$('#load').click(function(){
$.ajax({
url:'/more',
type:'get',
success:function(data){
$('.body').append(data);
}
})
})
})
</script>''' % post_body
@app.route('/more')
def load_post():
return generate_lorem_ipsum(n=1)
