flaskweb开发实战，入门进阶和原理解析第二章，http部分实例

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 = '
Hello %s!' % 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/')
def go_back(year):
    return "
welcome to %d"%(2018-year)


@app.route('/colors/')
def three_color(color):
    return "
Love is patient and kind. Love is not jealous or boastful or pround or rude."


@app.route('/brew/')
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/')
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 = '''



  
Note
  
to: Peter
  
from: Jane
  
heading: Reminder
  
body: Don't forget the party!


'''
        response = make_response(body)
        response.mimetype = 'text/html'
    elif content_type == 'xml':
        body = '''

  Peter
  Jane
  Reminder
  Don't forget the party!

'''
        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/')
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 '
Foo page
 Do something and redirect'\
            % url_for('do_something', next=request.full_path)


@app.route('/bar')
def bar():
    return '
Bar page
  Do something and redicrect'\
            % 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 '''
    
A very long post
    
%s
    Load More
    
    ''' % post_body


@app.route('/more')
def load_post():
    return generate_lorem_ipsum(n=1)

 

转载于:https://www.cnblogs.com/dairuiquan/p/10328129.html