tornado.web.Application类配置及使用

Posted 2020-08-05 gold叠

Application configuration

classtornado.web.Application(handlers=None, default_host=‘‘, transforms=None, **settings)[source]

A collection of request handlers that make up a web application.

Instances of this class are callable and can be passed directly to HTTPServer to serve the application:

application = web.Application([
    (r"/", MainPageHandler),
])
http_server = httpserver.HTTPServer(application)
http_server.listen(8080)
ioloop.IOLoop.current().start()

The constructor for this class takes in a list of URLSpec objects or (regexp, request_class) tuples. When we receive requests, we iterate over the list in order and instantiate an instance of the first request class whose regexp matches the request path. The request class can be specified as either a class object or a (fully-qualified) name.

Each tuple can contain additional elements, which correspond to the arguments to the URLSpecconstructor. (Prior to Tornado 3.2, only tuples of two or three elements were allowed).

A dictionary may be passed as the third element of the tuple, which will be used as keyword arguments to the handler’s constructor and initialize method. This pattern is used for theStaticFileHandler in this example (note that a StaticFileHandler can be installed automatically with the static_path setting described below):

application = web.Application([
    (r"/static/(.*)", web.StaticFileHandler, {"path": "/var/www"}),
])

We support virtual hosts with the add_handlers method, which takes in a host regular expression as the first argument:

application.add_handlers(r"www\.myhost\.com", [
    (r"/article/([0-9]+)", ArticleHandler),
])

You can serve static files by sending the static_path setting as a keyword argument. We will serve those files from the /static/ URI (this is configurable with the static_url_prefix setting), and we will serve /favicon.ico and /robots.txt from the same directory. A custom subclass ofStaticFileHandler can be specified with the static_handler_class setting.

settings

Additional keyword arguments passed to the constructor are saved in the settingsdictionary, and are often referred to in documentation as “application settings”. Settings are used to customize various aspects of Tornado (although in some cases richer customization is possible by overriding methods in a subclass of RequestHandler). Some applications also like to use the settings dictionary as a way to make application-specific settings available to handlers without using global variables. Settings used in Tornado are described below.

一般设置:

• autoreload: 如果设置 True,如果文件有变化进程将自动重启, 在 Debug mode and automatic reloading（DeBug模式和自动装载的情况下自动开启）.
• debug: 几种配置的集合, 具体查看 Debug mode and automatic reloading. 设置 debug=True 相当于设置 autoreload=True,compiled_template_cache=False, static_hash_cache=False, serve_traceback=True.
• default_handler_class and default_handler_args: 在页面没有找到（404错误的时候）自定义404错误页视图动作类及参数
• compress_response: 如果设置 True, responses（响应）将被自动压缩
• gzip: 在Tornado 4.0被compress_response代替
• log_function: 这个函数用来回调 RequestHandler 对象的处理结果，默认主程序导入logging并配置好的话会自动记录.也可以定制Application.log_request这个方法.
• serve_traceback: 如果设置 true,错误页面将包含错误跟踪
• ui_modules and ui_methods: 配置 UIModule 或 UI methods配置模版可用的帮助方法. 可以是一个模块、字典或一个模块或者字典的列表. 更多细节查看 UI modules

认证和安全设置:

• cookie_secret: 被 RequestHandler.get_secure_cookie和set_secure_cookie用来配置cookie的标志
• key_version: 被 set_secure_cookie 用来配置cookie的标志时cookie_secret的一个key
• login_url: 如果没有用户登录这个 authenticated 装饰器将被重新定义到. 可以进一步重写 RequestHandler.get_login_url
• xsrf_cookies: If true, Cross-site request forgery protection will be enabled.
• xsrf_cookie_version: Controls the version of new XSRF cookies produced by this server. Should generally be left at the default (which will always be the highest supported version), but may be set to a lower value temporarily during version transitions. New in Tornado 3.2.2, which introduced XSRF cookie version 2.
• xsrf_cookie_kwargs: May be set to a dictionary of additional arguments to be passed toRequestHandler.set_cookie for the XSRF cookie.
• twitter_consumer_key, twitter_consumer_secret, friendfeed_consumer_key,friendfeed_consumer_secret, google_consumer_key, google_consumer_secret, facebook_api_key,facebook_secret: Used in the tornado.auth module to authenticate to various APIs.

模版设置:

• autoescape: 制对模板的自动转义. 可以被设置为 None 以禁止转义, 或设置为一个所有输出都该传递过数 name . 默认是 "xhtml_escape". 可以在每个模板中改变使用 {% autoescape %} 指令.
• compiled_template_cache:  默认 True; 如果 False 每次请求将重新加载模版
• template_path: 模版文件目录. 可以被 RequestHandler.get_template_path获取进行重写
• template_loader: 分配一个 tornado.template.BaseLoader进行模版加载.如果设置了template_path和 autoescape将失效. 可以被 RequestHandler.create_template_loader进一步重写.
• template_whitespace: 对于模板中的空白处理; 详细用法请看tornado.template.filter_whitespace

静态文件设置:

• static_hash_cache: 默认 True; 如果 False 静态 urls 将重新加载静态文件
• static_path: 静态文件的目录
• static_url_prefix: 静态文件的Url前缀, 默认为 "/static/".
• static_handler_class, static_handler_args: 可以自定义处理静态文件的动作和参数，而不是默认的 tornado.web.StaticFileHandler. static_handler_args, 如果设置了，应该有一个字典被传入到动作类的 initialize 方法中

listen(port, address=‘‘, **kwargs)[source]

Starts an HTTP server for this application on the given port.

This is a convenience alias for creating an HTTPServer object and calling its listen method. Keyword arguments not supported by HTTPServer.listen are passed to the HTTPServerconstructor. For advanced uses (e.g. multi-process mode), do not use this method; create anHTTPServer and call its TCPServer.bind/TCPServer.start methods directly.

Note that after calling this method you still need to call IOLoop.current().start() to start the server.

Returns the HTTPServer object.

Changed in version 4.3: Now returns the HTTPServer object.

add_handlers(host_pattern, host_handlers)[source]

Appends the given handlers to our handler list.

Host patterns are processed sequentially in the order they were added. All matching patterns will be considered.

reverse_url(name, *args)[source]

Returns a URL path for handler named name

The handler must be added to the application as a named URLSpec.

Args will be substituted for capturing groups in the URLSpec regex. They will be converted to strings if necessary, encoded as utf8, and url-escaped.

log_request(handler)[source]

Writes a completed HTTP request to the logs.

By default writes to the python root logger. To change this behavior either subclass Application and override this method, or pass a function in the application settings dictionary as log_function.