Routes

routes – Routes module

Provides common classes and functions most users will want access to.

Module Contents

routes.request_config(original=False)

Returns the Routes RequestConfig object.

To get the Routes RequestConfig:

>>> from routes import *
>>> config = request_config()

The following attributes must be set on the config object every request:

mapper
mapper should be a Mapper instance thats ready for use
host
host is the hostname of the webapp
protocol
protocol is the protocol of the current request
mapper_dict
mapper_dict should be the dict returned by mapper.match()
redirect
redirect should be a function that issues a redirect, and takes a url as the sole argument
prefix (optional)
Set if the application is moved under a URL prefix. Prefix will be stripped before matching, and prepended on generation
environ (optional)

Set to the WSGI environ for automatic prefix support if the webapp is underneath a ‘SCRIPT_NAME’

Setting the environ will use information in environ to try and populate the host/protocol/mapper_dict options if you’ve already set a mapper.

Using your own requst local

If you have your own request local object that you’d like to use instead of the default thread local provided by Routes, you can configure Routes to use it:

from routes import request_config()
config = request_config()
if hasattr(config, 'using_request_local'):
    config.request_local = YourLocalCallable
    config = request_config()

Once you have configured request_config, its advisable you retrieve it again to get the object you wanted. The variable you assign to request_local is assumed to be a callable that will get the local config object you wish.

This example tests for the presence of the ‘using_request_local’ attribute which will be present if you haven’t assigned it yet. This way you can avoid repeat assignments of the request specific callable.

Should you want the original object, perhaps to change the callable its using or stop this behavior, call request_config(original=True).

class routes.Mapper(controller_scan=<function controller_scan at 0x101d88b90>, directory=None, always_scan=False, register=True, explicit=False)

Mapper handles URL generation and URL recognition in a web application.

Mapper is built handling dictionary’s. It is assumed that the web application will handle the dictionary returned by URL recognition to dispatch appropriately.

URL generation is done by passing keyword parameters into the generate function, a URL is then returned.

Create a new Mapper instance

All keyword arguments are optional.

controller_scan

Function reference that will be used to return a list of valid controllers used during URL matching. If directory keyword arg is present, it will be passed into the function during its call. This option defaults to a function that will scan a directory for controllers.

Alternatively, a list of controllers or None can be passed in which are assumed to be the definitive list of controller names valid when matching ‘controller’.

directory
Passed into controller_scan for the directory to scan. It should be an absolute path if using the default controller_scan function.
always_scan
Whether or not the controller_scan function should be run during every URL match. This is typically a good idea during development so the server won’t need to be restarted anytime a controller is added.
register
Boolean used to determine if the Mapper should use request_config to register itself as the mapper. Since it’s done on a thread-local basis, this is typically best used during testing though it won’t hurt in other cases.
explicit

Boolean used to determine if routes should be connected with implicit defaults of:

{'controller':'content','action':'index','id':None}

When set to True, these defaults will not be added to route connections and url_for will not use Route memory.

Additional attributes that may be set after mapper initialization (ie, map.ATTRIBUTE = ‘something’):

encoding
Used to indicate alternative encoding/decoding systems to use with both incoming URL’s, and during Route generation when passed a Unicode string. Defaults to ‘utf-8’.
decode_errors
How to handle errors in the encoding, generally ignoring any chars that don’t convert should be sufficient. Defaults to ‘ignore’.
minimization
Boolean used to indicate whether or not Routes should minimize URL’s and the generated URL’s, or require every part where it appears in the path. Defaults to True.
hardcode_names
Whether or not Named Routes result in the default options for the route being used or if they actually force url generation to use the route. Defaults to False.
connect(*args, **kargs)

Create and connect a new Route to the Mapper.

Usage:

m = Mapper()
m.connect(':controller/:action/:id')
m.connect('date/:year/:month/:day', controller="blog", action="view")
m.connect('archives/:page', controller="blog", action="by_page",
requirements = { 'page':'\d{1,2}' })
m.connect('category_list', 'archives/category/:section', controller='blog', action='category',
section='home', type='list')
m.connect('home', '', controller='blog', action='view', section='home')
create_regs(*args, **kwargs)
Atomically creates regular expressions for all connected routes
generate(*args, **kargs)

Generate a route from a set of keywords

Returns the url text, or None if no URL could be generated.

m.generate(controller='content',action='view',id=10)
match(url)

Match a URL against against one of the routes contained.

Will return None if no valid match is found.

resultdict = m.match('/joe/sixpack')
redirect(match_path, destination_path, *args, **kwargs)

Add a redirect route to the mapper

Redirect routes bypass the wrapped WSGI application and instead result in a redirect being issued by the RoutesMiddleware. As such, this method is only meaningful when using RoutesMiddleware.

By default, a 302 Found status code is used, this can be changed by providing a _redirect_code keyword argument which will then be used instead. Note that the entire status code string needs to be present.

When using keyword arguments, all arguments that apply to matching will be used for the match, while generation specific options will be used during generation. Thus all options normally available to connected Routes may be used with redirect routes as well.

Example:

map = Mapper()
map.redirect('/legacyapp/archives/{url:.*}, '/archives/{url})
map.redirect('/home/index', '/', _redirect_code='301 Moved Permanently')
resource(member_name, collection_name, **kwargs)

Generate routes for a controller resource

The member_name name should be the appropriate singular version of the resource given your locale and used with members of the collection. The collection_name name will be used to refer to the resource collection methods and should be a plural version of the member_name argument. By default, the member_name name will also be assumed to map to a controller you create.

The concept of a web resource maps somewhat directly to ‘CRUD’ operations. The overlying things to keep in mind is that mapping a resource is about handling creating, viewing, and editing that resource.

All keyword arguments are optional.

controller
If specified in the keyword args, the controller will be the actual controller used, but the rest of the naming conventions used for the route names and URL paths are unchanged.
collection

Additional action mappings used to manipulate/view the entire set of resources provided by the controller.

Example:

map.resource('message', 'messages', collection={'rss':'GET'})
# GET /message/rss (maps to the rss action)
# also adds named route "rss_message"
member

Additional action mappings used to access an individual ‘member’ of this controllers resources.

Example:

map.resource('message', 'messages', member={'mark':'POST'})
# POST /message/1/mark (maps to the mark action)
# also adds named route "mark_message"
new

Action mappings that involve dealing with a new member in the controller resources.

Example:

map.resource('message', 'messages', new={'preview':'POST'})
# POST /message/new/preview (maps to the preview action)
# also adds a url named "preview_new_message"
path_prefix
Prepends the URL path for the Route with the path_prefix given. This is most useful for cases where you want to mix resources or relations between resources.
name_prefix

Perpends the route names that are generated with the name_prefix given. Combined with the path_prefix option, it’s easy to generate route names and paths that represent resources that are in relations.

Example:

map.resource('message', 'messages', controller='categories', 
    path_prefix='/category/:category_id', 
    name_prefix="category_")
# GET /category/7/message/1
# has named route "category_message"
parent_resource

A dict containing information about the parent resource, for creating a nested resource. It should contain the member_name and collection_name of the parent resource. This dict will be available via the associated Route object which can be accessed during a request via request.environ['routes.route']

If parent_resource is supplied and path_prefix isn’t, path_prefix will be generated from parent_resource as “<parent collection name>/:<parent member name>_id”.

If parent_resource is supplied and name_prefix isn’t, name_prefix will be generated from parent_resource as “<parent member name>_”.

Example:

>>> from routes.util import url_for 
>>> m = Mapper() 
>>> m.resource('location', 'locations', 
...            parent_resource=dict(member_name='region', 
...                                 collection_name='regions'))
>>> # path_prefix is "regions/:region_id" 
>>> # name prefix is "region_"  
>>> url_for('region_locations', region_id=13) 
'/regions/13/locations'
>>> url_for('region_new_location', region_id=13) 
'/regions/13/locations/new'
>>> url_for('region_location', region_id=13, id=60) 
'/regions/13/locations/60'
>>> url_for('region_edit_location', region_id=13, id=60) 
'/regions/13/locations/60/edit'

Overriding generated path_prefix:

>>> m = Mapper()
>>> m.resource('location', 'locations',
...            parent_resource=dict(member_name='region',
...                                 collection_name='regions'),
...            path_prefix='areas/:area_id')
>>> # name prefix is "region_"
>>> url_for('region_locations', area_id=51)
'/areas/51/locations'

Overriding generated name_prefix:

>>> m = Mapper()
>>> m.resource('location', 'locations',
...            parent_resource=dict(member_name='region',
...                                 collection_name='regions'),
...            name_prefix='')
>>> # path_prefix is "regions/:region_id" 
>>> url_for('locations', region_id=51)
'/regions/51/locations'
routematch(url)

Match a URL against against one of the routes contained.

Will return None if no valid match is found, otherwise a result dict and a route object is returned.

resultdict, route_obj = m.match('/joe/sixpack')
class routes.URLGenerator(mapper, environ)

The URL Generator generates URL’s

It is automatically instantiated by the RoutesMiddleware and put into the wsgiorg.routing_args tuple accessible as:

url = environ['wsgiorg.routing_args'][0][0]

Or via the routes.url key:

url = environ['routes.url']

The url object may be instantiated outside of a web context for use in testing, however sub_domain support and fully qualified URL’s cannot be generated without supplying a dict that must contain the key HTTP_HOST.

Instantiate the URLGenerator

mapper
The mapper object to use when generating routes.
environ
The environment dict used in WSGI, alternately, any dict that contains at least an HTTP_HOST value.
routes.url_for(*args, **kargs)

Generates a URL

All keys given to url_for are sent to the Routes Mapper instance for generation except for:

anchor          specified the anchor name to be appened to the path
host            overrides the default (current) host if provided
protocol        overrides the default (current) protocol if provided
qualified       creates the URL with the host/port information as 
                needed

The URL is generated based on the rest of the keys. When generating a new URL, values will be used from the current request’s parameters (if present). The following rules are used to determine when and how to keep the current requests parameters:

  • If the controller is present and begins with ‘/’, no defaults are used
  • If the controller is changed, action is set to ‘index’ unless otherwise specified

For example, if the current request yielded a dict of {‘controller’: ‘blog’, ‘action’: ‘view’, ‘id’: 2}, with the standard ‘:controller/:action/:id’ route, you’d get the following results:

url_for(id=4)                    =>  '/blog/view/4',
url_for(controller='/admin')     =>  '/admin',
url_for(controller='admin')      =>  '/admin/view/2'
url_for(action='edit')           =>  '/blog/edit/2',
url_for(action='list', id=None)  =>  '/blog/list'

Static and Named Routes

If there is a string present as the first argument, a lookup is done against the named routes table to see if there’s any matching routes. The keyword defaults used with static routes will be sent in as GET query arg’s if a route matches.

If no route by that name is found, the string is assumed to be a raw URL. Should the raw URL begin with / then appropriate SCRIPT_NAME data will be added if present, otherwise the string will be used as the url with keyword args becoming GET query args.

routes.redirect_to(*args, **kargs)

Issues a redirect based on the arguments.

Redirect’s should occur as a “302 Moved” header, however the web framework may utilize a different method.

All arguments are passed to url_for to retrieve the appropriate URL, then the resulting URL it sent to the redirect function as the URL.

routes.mapper.strip_slashes(name)
Remove slashes from the beginning and end of a part/URL.
class routes.middleware.RoutesMiddleware(wsgi_app, mapper, use_method_override=True, path_info=True)

Routing middleware that handles resolving the PATH_INFO in addition to optionally recognizing method overriding.

Create a Route middleware object

Using the use_method_override keyword will require Paste to be installed, and your application should use Paste’s WSGIRequest object as it will properly handle POST issues with wsgi.input should Routes check it.

If path_info is True, then should a route var contain path_info, the SCRIPT_NAME and PATH_INFO will be altered accordingly. This should be used with routes like:

map.connect('blog/*path_info', controller='blog', path_info='')

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