06 flask源码剖析之路由加载

06 Flask源码之：路由加载

目录

• 06 Flask源码之：路由加载
  • 1.示例代码
  • 2.路由加载源码分析

1.示例代码

from flask import Flask

app = Flask(__name__,static_url_path='/xx')

@app.route('/index')
def index():
    return 'hello world'

2.路由加载源码分析

1. 先执行route函数

   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
   

2. 执行add_url_rule函数

   def add_url_rule(
       self,
       rule,
       endpoint=None,
       view_func=None,
       provide_automatic_options=None,
       **options
   ):
       if endpoint is None:
           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",)
   
               rule = self.url_rule_class(rule, methods=methods, **options)
   
               self.url_map.add(rule)
               if view_func is not None:
                   self.view_functions[endpoint] = view_func
   

   1. 将 url = /index 和 methods = [GET,POST] 和 endpoint = "index"封装到Rule对象
   2. 将Rule对象添加到 app.url_map中。
   3. 把endpoint和函数的对应关系放到 app.view_functions中。
   4. 当一个请求过来时，先拿路由在app.url_map找对应的别名，再在app.view_functions中找到别名对应的视图函数