Blocks selected by categories

[tazogil]

Please,
I want to give the possibility for a admin user to add some blocks in his pages through a select menu of (blocks) categories.
I think a injection field is the solution, so in my settings :
EXTRA_MODEL_FIELDS = (
(
"mezzanine.pages.models.Page.blocks",
"django.db.models.ManyToManyField",
("mezzanine_blocks.models.BlockCategory",),
{},
),
)
ERROR when running dev server :
pages.page: 'blocs' has an m2m relation with model mezzanine_blocks.models.BlockCategory, which has either not been installed or is abstract.
No error if I replace "mezzanine_blocks.models.BlockCategory" by "mezzanine_blocks.BlockCategory" .
But :
python manage.py schemamigration pages -v=3 --auto --stdout > mymigration.py
fails :
TypeError: 'NoneType' object has no attribute 'getitem'

am I missing something ? Is theire a better way to get that ?

[renyi]

Will take a look over the weekend.

[whardier]

How did this turn out?