root/trac-plugins/navaddplugin/navadd/navadd.py

from trac.core import *
from trac.web.chrome import INavigationContributor, ITemplateProvider
from trac.util import Markup
from trac.web.href import Href
from trac.ticket.report import ReportModule

class NavAdd(Component):
    """ Allows to add items to main and meta navigation bar"""
    implements(INavigationContributor)

    nav_contributors = ExtensionPoint(INavigationContributor)

    # INavigationContributor methods
    def get_active_navigation_item(self, req):
        return ''
                
    def get_navigation_items(self, req):
        add = self.env.config.get('navadd', 'add_items', ''). \
                replace(',', ' ').split()

        items = []
        for a in add:
            title = self.env.config.get('navadd', '%s.title' % a)
            url = self.env.config.get('navadd', '%s.url' % a)
            perm = self.env.config.get('navadd', '%s.perm' % a)
            target = self.env.config.get('navadd', '%s.target' % a)

            if url == '/report':
                url = self.get_first_report_url()

            if perm and not req.perm.has_permission(perm):
                continue

            if target not in ('mainnav', 'metanav'):
                target = 'mainnav'

            # the conditional below was added to make sure that we got the correct links in our multi-trac setup
            if url.startswith('/'):
                url = req.href.wiki().replace('/wiki', '') + url

            items.append((target, a, Markup('<a href="%s">%s</a>' % (url, title))))

        return items

    # The following method makes sure that we always get the first report for a given trac instance
    def get_first_report_url(self):
        db = self.env.get_db_cnx()
        cursor = db.cursor()
        cursor.execute('SELECT id AS report FROM report ORDER BY report LIMIT 1')
        row = cursor.fetchone()
        return '/report/' + str(row[0]);