[PATCH] - Enable Generic use of INavigationContributor

[ilias@…]

The following code

implements(INavigationContributor)

def get_navigation_items(self, req):
    yield 'projnav', 'guide', html.a( 'Project Guide', href=self.env.href.wiki('ProjectGuide') )

crashes within source:/trunk/trac/web/chrome.py​, as there's no Option "projnav_order" defined.

The attached patch enables that code without the need to define an Option.

This way, new custom navigation items can be generated dynamically, without any modifications in the source code / ini-files.

[Christian Boos]

A few (minor) remarks:

• in attachment:ChromeNavigationLinks.diff​, you used a "catch all" exception handler, which is generally a bad idea. Better be specific, in this case catching AttributeError is enough.
• if you can, please directly provide us with a full-contained example component, in this case something like:

  from trac.core import *
  from trac.util.html import html
  from trac.web.chrome import INavigationContributor
  
  class ProjectNavigation(Component):
      implements(INavigationContributor)
  
      def get_active_navigation_item(self, req):
          return 'guide'
      
      def get_navigation_items(self, req):
          yield 'projnav', 'guide', \
                html.a('Project Guide', href=req.href.wiki('ProjectGuide'))
  

Note also that you should get used to write req.href instead of self.env.href, as the latter form is now deprecated and will probably go away in 0.11.

As for the (fixed) patch itself, I'm +1 if you can show us how you intend to make use of the non-standard navigation category (i.e. something else than 'metanav' and 'mainnav').

[Matthew Good]

Well, if we're going to support custom navigation items then they should probably support ordering as well. However, I don't want to keep pushing back 0.10 for new features. Can we at least push this to 0.10.1 to get some more information?

[ilias@…]

Replying to cboos:

• if you can, please directly provide us with a full-contained example component,

the code is located ​here (corrected to use "self.env.href"):

As for the (fixed) patch itself, I'm +1 if you can show us how you intend to make use of the non-standard navigation category (i.e. something else than 'metanav' and 'mainnav').

You can find an example usage here (menu below project title):

​http://dev.lazaridis.com/base

I'll attach a corrected patch.

[ilias@…]

corrected to catch only AttributeError

[ilias@…]

Replying to mgood:

Well, if we're going to support custom navigation items then they should probably support ordering as well. However, I don't want to keep pushing back 0.10 for new features. Can we at least push this to 0.10.1 to get some more information?

• Custom navigation items are already supported. This patch removes just a tiny defect (possibly I should have filed a "defect" instead of "enhancement"), thus "custom navigation items" can be created again. This patch can/should be applied now, as it corrects the defect behaviour of the ordering-mechanism.

• See #3695: The ordering mechanism could be refactored in order to avoid the necessity to hardcode the option within chrome.py. This should be implemented later, as it changes behaviour and would possibly block the 0.10 release.

[Christian Boos]

Implemented slightly differently in r3717.

[ilias@…]

very nice, follow-up issue: #3704