Cannot add custom plugins that implement INavigationContributor

[ebcom]

In chrome.py, line 146

items.sort(lambda x,y: cmp(order.index(x[0]), order.index(y[0])))

fails to execute with the following dump:

Traceback (most recent call last):
  File "D:\tmp\trac\current\Lib\site-packages\trac\web\standalone.py", line 213, in _do_trac_req
    dispatch_request(path_info, req, env)
  File "D:\tmp\trac\current\Lib\site-packages\trac\web\main.py", line 419, in dispatch_request
    dispatcher.dispatch(req)
  File "D:\tmp\trac\current\Lib\site-packages\trac\web\main.py", line 276, in dispatch
    chrome.populate_hdf(req, chosen_handler)
  File "D:\tmp\trac\current\Lib\site-packages\trac\web\chrome.py", line 146, in populate_hdf
    items.sort(lambda x,y: cmp(order.index(x[0]), order.index(y[0])))
  File "D:\tmp\trac\current\Lib\site-packages\trac\web\chrome.py", line 146, in <lambda>
    items.sort(lambda x,y: cmp(order.index(x[0]), order.index(y[0])))
ValueError: list.index(x): x not in list

This error comes from the fact that navigation.items() contains statically defined items (categories: mainnav and metanav). These items are defined in trac.ini.

When the user adds a plugin that provides a navigation item, this item is not automatically registered into the appropriate category. This makes the sort method fail as the new navigation item is not part of the list.

Perharps this is not really a bug, if the plugin is expected to be registered into the appropriate trac.ini [trac] section.

However, I don't understand why the same information is duplicated:

• in the plugin python code, where get_navigation_items should return the navigation category as the first item
• in the trac.ini file, where it should be statically added to the same navigation category

[Emmanuel Blot]

sorry about emails: eblot and ebcom are the same person: myself ;-)

[Christopher Lenz]

This should be fixed in [1695].

To answer your question: the trac/mainnav and trac/metanav options are not for registering navigation contributors, it's for defining the order in which nav items appear. If a navigation item is not in the respective list, it just gets appended at the end.