Flask 基础组件（三）：路由系统

1. 常见路由

• @app.route(‘/user/<username>‘)
• @app.route(‘/post/<int:post_id>‘)
• @app.route(‘/post/<float:post_id>‘)
• @app.route(‘/post/<path:path>‘)
• @app.route(‘/login‘, methods=[‘GET‘, ‘POST‘])

常用路由系统有以上五种，所有的路由系统都是基于一下对应关系来处理：

DEFAULT_CONVERTERS = {
    ‘default‘:          UnicodeConverter,
    ‘string‘:           UnicodeConverter,
    ‘any‘:              AnyConverter,
    ‘path‘:             PathConverter,
    ‘int‘:              IntegerConverter,
    ‘float‘:            FloatConverter,
    ‘uuid‘:             UUIDConverter,
}

2.注册路由原理

案例一：

def auth(func):
            def inner(*args, **kwargs):
                print(‘before‘)
                result = func(*args, **kwargs)
                print(‘after‘)
                return result

        return inner

        @app.route(‘/index.html‘,methods=[‘GET‘,‘POST‘],endpoint=‘index‘)
        @auth
        def index():
            return ‘Index‘

        或
        
        def index():
            return "Index"

        self.add_url_rule(rule=‘/index.html‘, endpoint="index", view_func=index, methods=["GET","POST"])
        or
        app.add_url_rule(rule=‘/index.html‘, endpoint="index", view_func=index, methods=["GET","POST"])
        app.view_functions[‘index‘] = index

案例二：

def auth(func):
            def inner(*args, **kwargs):
                print(‘before‘)
                result = func(*args, **kwargs)
                print(‘after‘)
                return result

        return inner

        class IndexView(views.View):
            methods = [‘GET‘]
            decorators = [auth, ]

            def dispatch_request(self):
                print(‘Index‘)
                return ‘Index!‘

        app.add_url_rule(‘/index‘, view_func=IndexView.as_view(name=‘index‘))  # name=endpoint



        或


        class IndexView(views.MethodView):
            methods = [‘GET‘]
            decorators = [auth, ]

            def get(self):
                return ‘Index.GET‘

            def post(self):
                return ‘Index.POST‘


        app.add_url_rule(‘/index‘, view_func=IndexView.as_view(name=‘index‘))  # name=endpoint

add_url_rule方法

@app.route和app.add_url_rule参数：
            rule,                       URL规则
            view_func,                  视图函数名称
            defaults=None,              默认值,当URL中无参数，函数需要参数时，使用defaults={‘k‘:‘v‘}为函数提供参数
            endpoint=None,              名称，用于反向生成URL，即： url_for(‘名称‘)
            methods=None,               允许的请求方式，如：["GET","POST"]
            

            strict_slashes=None,        对URL最后的 / 符号是否严格要求，
                                        如：
                                            @app.route(‘/index‘,strict_slashes=False)，
                                                访问 http://www.xx.com/index/ 或 http://www.xx.com/index均可
                                            @app.route(‘/index‘,strict_slashes=True)
                                                仅访问 http://www.xx.com/index 
            redirect_to=None,           重定向到指定地址
                                        如：
                                            @app.route(‘/index/<int:nid>‘, redirect_to=‘/home/<nid>‘)
                                            或
                                            def func(adapter, nid):
                                                return "/home/888"
                                            @app.route(‘/index/<int:nid>‘, redirect_to=func)
            subdomain=None,             子域名访问
                                                from flask import Flask, views, url_for

                                                app = Flask(import_name=__name__)
                                                app.config[‘SERVER_NAME‘] = ‘wupeiqi.com:5000‘


                                                @app.route("/", subdomain="admin")
                                                def static_index():
                                                    """Flask supports static subdomains
                                                    This is available at static.your-domain.tld"""
                                                    return "static.your-domain.tld"


                                                @app.route("/dynamic", subdomain="<username>")
                                                def username_index(username):
                                                    """Dynamic subdomains are also supported
                                                    Try going to user1.your-domain.tld/dynamic"""
                                                    return username + ".your-domain.tld"


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

3 自定义路由

from flask import Flask, views, url_for
            from werkzeug.routing import BaseConverter

            app = Flask(import_name=__name__)


            class RegexConverter(BaseConverter):
                """
                自定义URL匹配正则表达式
                """
                def __init__(self, map, regex):
                    super(RegexConverter, self).__init__(map)
                    self.regex = regex

                def to_python(self, value):
                    """
                    路由匹配时，匹配成功后传递给视图函数中参数的值
                    :param value: 
                    :return: 
                    """
                    return int(value)

                def to_url(self, value):
                    """
                    使用url_for反向生成URL时，传递的参数经过该方法处理，返回的值用于生成URL中的参数
                    :param value: 
                    :return: 
                    """
                    val = super(RegexConverter, self).to_url(value)
                    return val

            # 添加到flask中
            app.url_map.converters[‘regex‘] = RegexConverter


            @app.route(‘/index/<regex("\d+"):nid>‘)
            def index(nid):
                print(url_for(‘index‘, nid=‘888‘))
                return ‘Index‘


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

b. 自定制正则路由匹配