rebuild mptt tree

gistfile1.py

# -*- coding: UTF-8 -*-
from django.core.management.base import BaseCommand, CommandError
from cms.models.pagemodel import Page
from optparse import make_option


def rebuild_tree(parent, left=1, recursion_level=0, commit=False):

    right = left + 1

    page = Page.objects.filter(id=parent).get()

    # element header
    print "%s(%02d) %s" % ('\t' * recursion_level, page.id, page.get_title())

    children = Page.objects.filter(parent=parent)
    for child in children:
        right = rebuild_tree(child.id, left=right, recursion_level=recursion_level + 1, commit=commit)

    # element footer
    print "%s%s-%s=>%s-%s " % ('\t' * recursion_level, page.lft, page.rght, left, right)

    # save
    page.lft = left
    page.rght = right
    if commit:
        page.save()

    return right + 1


class Command(BaseCommand):

    args = '<page_id page_id ...> [--dry-run]'
    help = """
This script attempts to rebuild a malformed django-cms-mptt tree. It checks the
parent_id field only. This means it will potentially reorder elements of the
same level as it does not check their left and right values. The output might
appear somewhat counter-intuitive to you, an element with children will have its
body split by children elements. Have a look at the example:

(id) parent_element_title
        (id) child_element_title
        13-14=>13-14  # child element footer
12-15=>12-15  # parent element footer

Numbers' format: left_before-right_before=>left_after-right_after.

You may either provide a list of ids that you want to rebuild (and children thereof)
or parse all top level elements by providing no command line arguments.

Adapted for python from http://www.sitepoint.com/hierarchical-data-database-3/
by tu-br, 1338913297 ;)
    """
    option_list = BaseCommand.option_list + (
    make_option('--dry-run',
        action='store_true',
        dest='dry-run',
        default=False,
        help='Don\'t commit, just list the tree with proposed changes. '),
    )

    def handle(self, *args, **options):

        commit = False if options['dry-run'] else True  # whether to commit changes

        commit or self.stdout.write("### This is a dry run only. No changes will be made to the database. ###\n")

        if len(args) > 0:
            for page_id in args:
                try:
                    page = Page.objects.get(pk=int(page_id))
                    rebuild_tree(page.id, commit=commit)
                except Page.DoesNotExist:
                    raise CommandError('Page "%s" does not exist' % page_id)
        else:
            top_level_cms_pages = Page.objects.all().filter(parent=None)
            for top_level_cms_page in top_level_cms_pages:
                    rebuild_tree(top_level_cms_page.id, commit=commit)

        commit or self.stdout.write("### This is a dry run only. No changes will be made to the database. ###\n")