Mongoframes

Previous to this release projections within `$sub` or `$sub.` where simply ignored and the projection was converted to True for the key, for example:

python
lairs = Lair.many(
projection={
'_id': True,
'inventory': {
'$sub': Inventory,
'gold': True
}
)


Previously used the projection:


{
'_id: True,
'inventory': True
}


In this release this will now project to:



{
'_id: True,
'inventory.gold': True
}


NOTE: This release is a minor release as whilst this should effect existing code if you've previous been setting projections (which simply were ignored before) this could potentially break this code.

For example this is now possible:


projection={
'employees': {
'$ref': Employee,
'$slice': 2,
'name': True
}
}


So get the first 2 employee Ids in an array of employee Ids stored against the field `employees` and project them as Employee documents selecting only the name field for each.