wsgi_tools.routing module¶

With routing you can forward your request to specific WSGI-apps.

There are two main classes in this module: Router() and Rule()

The Router() is the WSGI-app, which uses rules to identify, to which WSGI-app it should forward.

You construct the Router() with a list of all rules you use and with an arg for each route and rule.

The Rule() defines if the request and the (arg of this rule in the) route match.

Example

>>> from wsgi_tools.routing import CONTENT_TYPE_RULE, METHOD_RULE, PathRule, Router

>>> path_rule = PathRule()

>>> app = Router(
...     [path_rule, METHOD_RULE, CONTENT_TYPE_RULE],
...     {
...         (('/create',), 'POST', 'json'): create_app,
...         (('/', int, '/options'), 'GET', None): options_app
...     }
... )

wsgi_tools.routing.CONTENT_TYPE_RULE = <wsgi_tools.routing.ContentTypeRule object>¶

A rule which checks whether the content_types match.

The arg you have to specifiy in each route is a str which represents the content-type or None if you do not expect content in this route (e.g. for a GET request).

If the arg is a str and includes a /, the rule will match, if arg and content-type match exactly.

If the arg is a str, but it does not includes any /, the rule will match, if the arg is located at any place after the / in the content type.

For example:

json matches application/json, application/foo+json, hello/foo+json+bar, etc.

application/json only matches application/json.

class wsgi_tools.routing.ContentTypeRule¶

Bases: wsgi_tools.routing.Rule

A rule which checks whether the content_types match.

The arg you have to specifiy in each route is a str which represents the content-type or None if you do not expect content in this route (e.g. for a GET request).

If the arg is a str and includes a /, the rule will match, if arg and content-type match exactly.

If the arg is a str, but it does not includes any /, the rule will match, if the arg is located at any place after the / in the content type.

For example:

json matches application/json, application/foo+json, hello/foo+json+bar, etc.

application/json only matches application/json.

Note

You can use the constant CONTENT_TYPE_RULE(), because this rule does not have any attributes.

check(environ, value)¶

The Method, which controls, whether a request and a route are matching this rule.

Parameters

environ (dict) – A WSGI-environ
value – the value of this rule for a route

Returns

True if environ and value are matching, False otherwise

Return type

bool

get_exception()¶

If no route matches this rule, an exception has to be thrown.

Returns: The exception which will be thrown, if no route supports thie rule.
Return type: HTTPException

wsgi_tools.routing.METHOD_RULE = <wsgi_tools.routing.MethodRule object>¶

A rule which checks whether the http methods match.

The arg you have to specifiy in each route is a str representing the http-method (e.g. 'GET', 'POST' or 'DELETE').

class wsgi_tools.routing.MethodRule¶

Bases: wsgi_tools.routing.Rule

A rule which checks whether the http methods match.

The arg you have to specifiy in each route is a str representing the http-method (e.g. 'GET', 'POST' or 'DELETE').

Note

You can use the constant METHOD_RULE(), because this rule does not have any attributes.

check(environ, value)¶

The Method, which controls, whether a request and a route are matching this rule.

Parameters

environ (dict) – A WSGI-environ
value – the value of this rule for a route

Returns

True if environ and value are matching, False otherwise

Return type

bool

get_exception()¶

If no route matches this rule, an exception has to be thrown.

Returns: The exception which will be thrown, if no route supports thie rule.
Return type: HTTPException

class wsgi_tools.routing.PathRule¶

Bases: wsgi_tools.routing.Rule

A Rule, which controls the path of the request.

The arg you have to specifiy in each route is a tuple or a list. This tuple or list has to begin with a string.

The simplest arg is a tuple, which is only one string.

('/',) is the root document.

('/hello',) is http://{host}/hello

You get an generic path, if you include callables, which have a str as the only arg and raise a ValueError if the input is wrong.

Examples for these callables are int and float, but you can create your own functions as well.

It is not allowed that two of these callables are directly follow upon each other.

('/', str, '/foo') for /bar/foo and args is ['bar'] or /hello/foo and args is ['hello'].

('/id/', int, '/user/', str, '/create') for /id/321/user/root/create and args is [321, 'root'].

args¶

The list of the generic parts of the path.

Type: list

check(environ, value)¶

The Method, which controls, whether a request and a route are matching this rule.

Parameters

environ (dict) – A WSGI-environ
value – the value of this rule for a route

Returns

True if environ and value are matching, False otherwise

Return type

bool

get_exception()¶

If no route matches this rule, an exception has to be thrown.

Returns: The exception which will be thrown, if no route supports thie rule.
Return type: HTTPException

class wsgi_tools.routing.Router(rules, routes)¶

Bases: object

The WSGI-app, which forwards requests on their environ.

Parameters

rules (list(Rule)) – A list of the rules you want to use.
routes (dict) – A dict representing the routes. A route is a dict-entry with a tuple or list with the args for all rules for this route as the key and the WSGI-app the router should forward to as the value.

class wsgi_tools.routing.Rule¶

Bases: object

A Rule is an object, which defines if requests can be forwarded to a route.

Some Rules also store data of the current request which are accessible from the code which is executed at this request.

abstract check(environ, value)¶

The Method, which controls, whether a request and a route are matching this rule.

Parameters

environ (dict) – A WSGI-environ
value – the value of this rule for a route

Returns

True if environ and value are matching, False otherwise

Return type

bool

abstract get_exception()¶

If no route matches this rule, an exception has to be thrown.

Returns: The exception which will be thrown, if no route supports thie rule.
Return type: HTTPException