URL publishing

(cubicweb_web.views.urlpublishing)

You can write your own URLPathEvaluator class to handle custom paths. For instance, if you want /my-card-id to redirect to the corresponding card’s primary view, you would write:

class CardWikiidEvaluator(URLPathEvaluator):
    priority = 3 # make it be evaluated *before* RestPathEvaluator

    def evaluate_path(self, req, segments):
        if len(segments) != 1:
            raise PathDontMatch()
        rset = req.execute('Any C WHERE C wikiid %(w)s',
                           {'w': segments[0]})
        if len(rset) == 0:
            # Raise NotFound if no card is found
            raise PathDontMatch()
        return None, rset

On the other hand, you can also deactivate some of the standard evaluators in your final application. The only thing you have to do is to unregister them, for instance in a registration_callback in your cube:

def registration_callback(vreg):
    vreg.unregister(RestPathEvaluator)

You can even replace the cubicweb_web.views.urlpublishing.URLPublisherComponent class if you want to customize the whole toolchain process or if you want to plug into an early enough extension point to control your request parameters:

class SanitizerPublisherComponent(URLPublisherComponent):
    """override default publisher component to explicitly ignore
    unauthorized request parameters in anonymous mode.
    """
    unauthorized_form_params = ('rql', 'vid', '__login', '__password')

    def process(self, req, path):
        if req.session.anonymous_session:
            self._remove_unauthorized_params(req)
        return super(SanitizerPublisherComponent, self).process(req, path)

    def _remove_unauthorized_params(self, req):
        for param in req.form.keys():
            if param in self.unauthorized_form_params:
                 req.form.pop(param)


def registration_callback(vreg):
    vreg.register_and_replace(SanitizerPublisherComponent, URLPublisherComponent)

URL rewriting

(cubicweb_web.views.urlrewrite)

class cubicweb_web.views.urlrewrite.URLRewriter(req, **extra)

Base class for URL rewriters.

Url rewriters should have a rules dict that maps an input URI to something that should be used for rewriting.

The actual logic that defines how the rules dict is used is implemented in the rewrite method.

A priority attribute might be used to indicate which rewriter should be tried first. The higher the priority is, the earlier the rewriter will be tried.

class cubicweb_web.views.urlrewrite.SimpleReqRewriter(req, **extra)

The SimpleReqRewriters uses a rules dict that maps input URI (regexp or plain string) to a dictionary to update the request’s form.

If the input uri is a regexp, group substitution is allowed.

rewrite(req, uri)

for each input, output `in rules, if `uri matches input, req’s form is updated with output

class cubicweb_web.views.urlrewrite.SchemaBasedRewriter(req, **extra)

Here, the rules dict maps regexps or plain strings to callbacks that will be called with inputurl, uri, req, schema as parameters.

SimpleReqRewriter is enough for a certain number of simple cases. If it is not sufficient, SchemaBasedRewriter allows to do more elaborate things.

Here is an example of SimpleReqRewriter usage with plain string:

from cubicweb_web.views.urlrewrite import SimpleReqRewriter
class TrackerSimpleReqRewriter(SimpleReqRewriter):
    rules = [
     ('/versions', dict(vid='versionsinfo')),
     ]

When the url is <base_url>/versions, the view with the __regid__ versionsinfo is displayed.

Here is an example of SimpleReqRewriter usage with regular expressions:

from cubicweb_web.views.urlrewrite import (
    SimpleReqRewriter, rgx)

class BlogReqRewriter(SimpleReqRewriter):
    rules = [
        (rgx('/blogentry/([a-z_]+)\.rss'),
         dict(rql=('Any X ORDERBY CD DESC LIMIT 20 WHERE X is BlogEntry,'
                   'X creation_date CD, X created_by U, '
                   'U login "%(user)s"'
                   % {'user': r'\1'}), vid='rss'))
        ]

When a url matches the regular expression, the view with the __regid__ rss which match the result set is displayed.

To deal with URL rewriting with an underlying RQL query, it is possible to specify the behaviour in the case of an empty rset with the option empty_rset_raises_404.

The following example shows a SimpleReqRewriter usage with the empty_rset_raises_404 option set to True. In this case, the path mycwetypeurl/pouet will return a 404. Without this option, it would return a 200.

from cubicweb_web.views.urlrewrite import (
    SimpleReqRewriter, rgx)

class MyRewriter(SimpleReqRewriter):
    rules = [(rgx(r'/mycwetypeurl/([^/]+)'),
                                dict(vid='primary',
                                     rql=r'Any T WHERE T is CWEType, T name "\1"',
                                     empty_rset_raises_404=True),)]

Here is an example of SchemaBasedRewriter usage:

from cubicweb_web.views.urlrewrite import (
    SchemaBasedRewriter, rgx, build_rset)

class TrackerURLRewriter(SchemaBasedRewriter):
    rules = [
        (rgx('/project/([^/]+)/([^/]+)/tests'),
         build_rset(rql='Version X WHERE X version_of P, P name %(project)s, X num %(num)s',
                    rgxgroups=[('project', 1), ('num', 2)], vid='versiontests')),
        ]