How do I rebuild my django-mptt tree?
Solution 1
AttributeError: Manager isn't accessible via MyObj instances
mptt Manager
inherits from django.db.models.Manager
which can not be accessed via model instances but only via model classes. More infos:Retrieving objects
The model class here is MyObj
. You are using a model instance my_rootnode
the correct usage is:
MyObj.tree.rebuild()
(documentation link)
this will build MyObj tree.
Solution 2
work for me:
MenuItem.objects.rebuild()
Solution 3
Recent MPTT version seem to require the following command. At least it worked for me today, although dash in front indicates that tree manager is private, and probably should not be accessed directly:
MyObj._tree_manager.rebuild()
Solution 4
manji is indeed right, you need to use the model class to call rebuild.
However, if you want to rebuild the tree only for a specific object and its descendants, you can use :
MyObj.tree.partial_rebuild(tree_id)
.
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Hobhouse
Updated on May 27, 2022Comments
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Hobhouse over 1 year
I'm using django-mptt 0.4.2, and want to rebuild a tree.
The tree manager has a method rebuild() which I try to access like this:
>>> my_rootnode = MyObj.objects.get(id=12) >>> my_rootnode.tree.rebuild() Traceback (most recent call last): File "<console>", line 1, in <module> File "/usr/local/lib/python2.6/dist-packages/django/db/models/manager.py", line 211, in __get__ raise AttributeError("Manager isn't accessible via %s instances" % type.__name__) AttributeError: Manager isn't accessible via MyObj instances
I'm obviously doing this wrong. How should I access the rebuild method?
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Thomas Kremmel over 10 yearsNote that partial_rebuild is not yet part of an official release which is as of today 0.5.5. Thus if you install via pip partial_rebuild will not be available. Anyhow you could use the master branch directly from github. See this: github.com/django-mptt/django-mptt/issues/250 ..
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chhantyal almost 10 yearsIt's now part of 0.6.0 release.
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JxAxMxIxN over 6 yearsNote that MyObj should be the actual Model Class and not an object. Tested with Django-MPTT 0.8.7 - It rebuilt my broken relations, but there was still an issue with my root categories which were parentless.
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partofthething about 5 yearsIn Django-MPTT 0.9.1 this gives an AttributeError:
AttributeError: type object 'Node' has no attribute 'tree'
. Looks likeMyObj.objects.rebuild()
is the way to go now, though that doesn't seem to work in a migration script because for some reason the Manager isn't a TreeManager then. In the shell all is good. Odd.