BlueBream The Web Component Framework

11.3. Retrieving absolute URL for an object

BlueBream has a different, cleaner approach on how to handle URLs of objects. This recipe presents how to retrieve an URL for a given object, and the logic behind. This HOWTO assume that you have included zope.traversing.browser in your etc/site.zcml like this:

<include package="zope.traversing.browser" />

11.3.1. Understanding URLs

Each persistent object stored in the ZODB is reached through views, that handles its display. The URL is the location from wich the object is reached through the browser. For example, is the user tries to display foo , which is in bar , she will type: http://server/foo/bar. The object is pulled by the publisher which traverses the tree of objects from the root. In our case, it traverses foo , ask it for bar , and so on. foo will point bar to the publisher, because its __name__ property is bar .

Getting an object URL is done by doing the back trip from the object to the root, building the string with the names of all traversed objects.

The main difference with older behaviors is that bar doesn’t hold its URL.

11.3.2. Getting an object URL

The URL of all publishable objects can be retrieved this way, and a generic view class, called AbsoluteURL provide this feature under the absolute_url name.

In a ZPT for instance, a given object URL can be retrieved with: my_object/@@absolute_url. In Python code, a call to the zope.traversing.browser.absoluteurl.absoluteURL function can be used.

To try this function, open the debug shell:

$ ./bin/paster shell debug.ini

You can retrieve the root object URL, like this:

>>> from zope.publisher.browser import TestRequest
>>> from zope.traversing.browser.absoluteurl import absoluteURL
>>> request = TestRequest()
>>> absoluteURL(root, request)

In the above example, root is the root folder object.

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