findig.dispatcher – Low-level dispatchers for Findig applications

This low-level module defines the Dispatcher class, from which findig.App derives.

class findig.dispatcher.Dispatcher(formatter=None, parser=None, error_handler=None, pre_processor=None, post_processor=None)

A Dispatcher creates resources and routes requests to them.

Parameters:

• formatter – A function that converts resource data to a string string suitable for output. It returns a 2-tuple: (mime_type, output). If not given, a generic findig.content.Formatter is used.
• parser – A function that parses request input and returns a 2-tuple: (mime_type, data). If not given, a generic findig.content.Parser.
• error_handler – A function that converts an exception to a Response. If not given, a generic findig.content.ErrorHandler is used.
• pre_processor – A function that is called on request data just after is is parsed.
• post_processor – A function that is called on resource data just before it is formatted.

This class is fairly low-level and shouldn’t be instantiated directly in application code. It does however serve as a base for findig.App.

formatter

If a formatter function was given to the constructor, then that is used. Otherwise, a generic findig.content.Formatter is used.

parser

The value that was passed for parser to the constructor. If no argument for parser was given to the constructor, then a generic findig.content.Parser is used.

error_handler

The value that was passed for error_handler to the constructor, or if None was given, then a generic findig.content.ErrorHandler.

response_class

A class that is used to construct responses after they’re returned from formatters.

alias of Response

build_rules()

Return a generator for all of the url rules collected by the Dispatcher.

Return type:Iterable of werkzeug.routing.Rule

Note

This method will ‘freeze’ resource names; do not change resource names after this function is invoked.

dispatch()

Dispatch the current request to the appropriate resource, based on which resource the rule applies to.

This function requires an active request context in order to work.

resource(wrapped, **args)

Create a findig.resource.Resource instance.

Parameters:wrapped – A wrapped function for the resource. In most cases, this should be a function that takes named route arguments for the resource and returns a dictionary with the resource’s data.

The keyword arguments are passed on directly to the constructor for Resource, with the exception that name will default to {module}.{name} of the wrapped function if not given.

This method may also be used as a decorator factory:

@dispatcher.resource(name='my-very-special-resource')
def my_resource(route, param):
    return {'id': 10, ... }

In this case the decorated function will be replaced by a Resource instance that wraps it. Any keyword arguments passed to the decorator factory will be handed over to the Resource constructor. If no keyword arguments are required, then @resource may be used instead of @resource().

Note

If this function is used as a decorator factory, then a keyword parameter for wrapped must not be used.

route(resource, rulestr, **ruleargs)

Add a route to a resource.

Adding a URL route to a resource allows Findig to dispatch incoming requests to it.

Parameters:

• resource (Resource or function) – The resource that the route will be created for.
• rulestr (str) – A URL rule, according to werkzeug’s specification.

See werkzeug.routing.Rule for valid rule parameters.

This method can also be used as a decorator factory to assign route to resources using declarative syntax:

@route("/index")
@resource(name='index')
def index_generator():
    return ( ... )

unrouted_resources

A list of resources created by the dispatcher which have no routes to them.