Flask learning framework (c)

@ App.route this section we do not have to write routing, but by add_url_rule

Traditional writing ( Int type parameter passing, endpoint is aliased)

@app.route('/detail/<int:nid>',methods=['GET'],endpoint='detail')

The default converter

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

Nature routing system (source code analysis)

From the start of the route @ app.route

App.py source (the source can be seen from the following route is essentially add_url_rule. Self Here the object is instantiated, that is, before the app)

    def route(self, rule, **options)：

        def decorator(f):
            endpoint = options.pop("endpoint", None)
            self.add_url_rule(rule, endpoint, f, **options)
            return f

        return decorator

Then jump to add_url_rule in

@setupmethod
    def add_url_rule(
        self,
        rule,  #视图函数路由
        endpoint=None,  #取别名（非必填）
        view_func=None,  #这个就是上一个跳转过来的f,就是视图函数名（必填）
        provide_automatic_options=None,
        **options
    ):
   
        if endpoint is None:  #如果endpoint(别名)没填，就进入_endpoint_from_view_func看看
            endpoint = _endpoint_from_view_func(view_func)
        options["endpoint"] = endpoint
        methods = options.pop("methods", None)
        if methods is None:
            methods = getattr(view_func, "methods", None) or ("GET",)
        if isinstance(methods, string_types):
            raise TypeError(
                "Allowed methods have to be iterables of strings, "
                'for example: @app.route(..., methods=["POST"])'
            )
        methods = set(item.upper() for item in methods)

        # Methods that should always be added
        required_methods = set(getattr(view_func, "required_methods", ()))

        if provide_automatic_options is None:
            provide_automatic_options = getattr(
                view_func, "provide_automatic_options", None
            )

        if provide_automatic_options is None:
            if "OPTIONS" not in methods:
                provide_automatic_options = True
                required_methods.add("OPTIONS")
            else:
                provide_automatic_options = False

        # Add the required methods now.
        methods |= required_methods

        rule = self.url_rule_class(rule, methods=methods, **options)
        rule.provide_automatic_options = provide_automatic_options

        self.url_map.add(rule)
        if view_func is not None:
            old_func = self.view_functions.get(endpoint)
            if old_func is not None and old_func != view_func:
                raise AssertionError(
                    "View function mapping is overwriting an "
                    "existing endpoint function: %s" % endpoint
                )
            self.view_functions[endpoint] = view_func

Enter ** _ endpoint_from_view_func ** Take a look at how the alias ()

assert view_func is not None, "expected view func if endpoint is not provided."
return view_func.__name__

The first sentence was never carried out, to see the second sentence, the name is the view of the function name, this is login

Use alias (url_for): login access path, returns 123

from flask import Flask,url_for
app=Flask(__name__)
app.debug=True
def index():
    return '123'
app.add_url_rule('/index',view_func=index,endpoint='sb',methods=['POST',"GET"])


def login():
    real_url=url_for("sb")
    return real_url
app.add_url_rule('/login',view_func=index,methods=['POST',"GET"])
if __name__ == '__main__': 
　　app.run()

add_url_rule parameters are summarized:

rule:必填参数，就是跳转路由
endpoint:非必填参数，如果不填就是视图函数名。如果设置了endpoint，就在视图函数中通过url_for使用，不能设置重复,用于反向生成URL,即： url_for('名称')
view_func:也就是请求该路由时，相应的视图函数名称
methods:设置请求方式，默认是get请求，如：['GET','POST']

add_url_rule additional parameters:

defaults = None, 默认值, 当URL中无参数，函数需要参数时，使用defaults = {'k': 'v'}

#对URL最后的 / 符号是否严格要求，False是非严格模式，True严格模式，默认是严格模式
strict_slashes = None
  '''
        @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
    '''
#重定向到指定地址
redirect_to = None, 
    '''
        @app.route('/index/<int:nid>', redirect_to='/home/<nid>')
    '''

Summary code examples:

from  flask import Flask,url_for
app=Flask(__name__)
app.debug=True

def login(nid):
    print(type(nid),nid)
    return "ojbk_login"
app.add_url_rule('/login/<string:nid>',view_func=login,endpoint="sb",methods=['POST',"GET"])

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

Known parameters may also be provided: adding known parameter data type, transmission parameters view function