CRUDLookup

The CRUDLookup wasn't easy to implement, but it is now working like a charm (or kinda actually, I'm not really satisfied on how it's working).

You can't define your 'lookup' relation directly inside your model, and I'm really sorry about that, but it's the only way I found to make it work for the moment.

I'm still working on it, and I hope to find a better way to do it, but for now, it's working .

How to use it ?

The parent model should have a field with an Union type, which means that it should look like below :

# Parent
class ParentModel(MongoModel):
    id: Annotated[ObjectId, MongoObjectId] | None = None
    childs: Optional[Union[list[ChildModel], ChildModel]] = None

# Child
class ChildModel(MongoModel):
    id: Annotated[ObjectId, MongoObjectId] | None = None
    parent_id: Annotated[ObjectId, MongoObjectId]

Then, you can define your lookup like this :

from fastapi_crudrouter_mongodb import (
    ObjectId,
    MongoObjectId,
    MongoModel,
    CRUDRouter,
    CRUDLookup)

# Define your lookup
child_lookup = CRUDLookup(
    model=ChildModel,
    collection_name="childrens",
    prefix="childrens",
    local_field="_id",
    foreign_field="parent_id"
)

# Then, you can use it in your CRUDRouter
parent_controller = CRUDRouter(
    model=ParentModel,
    db=db,
    collection_name="parents",
    lookups=[child_lookup],
    prefix="/parents",
    tags=["parents"],
)

The type should look like above because if you want to use the following route : /parents/{id}/childrens/{id} , it will return the child item as an object an not a list.

Output Schemas

---

If you've perused the CRUDRouter documentation, you may have observed the option to utilize an output schema in response to your API requests. I've extended this capability to CRUDLookups as well in version 0.1.0. ✨

How to use output schema ?

In this example, both the parent and the child have an output schema. As illustrated, the child utilizes the parent's output schema as a foundation.

    # Database Model
    class MessageModel(MongoModel):
        id: Annotated[ObjectId, MongoObjectId] | None = None
        message: str
        user_id: Annotated[ObjectId, MongoObjectId]
        created_at: str | None = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
        updated_at: str | None = datetime.now().strftime("%Y-%m-%d %H:%M:%S")

    class UserModel(MongoModel):
        id: Annotated[ObjectId, MongoObjectId] | None = None
        name: str
        email: str
        password: str
        addresses: Optional[list[AddressModel]] = []
        messages: Optional[Union[list[MessageModel], MessageModel]] = None

    # Model Out -> Schema
    class UserModelOut(MongoModel):
        id: str
        name: str
        email: str
        addresses: list[AddressModel] = []


    class LookupModelOut(UserModelOut):
        messages: list[MessageModel] | MessageModel


    messages_lookup = CRUDLookup(
    model=MessageModel,
    model_out=LookupModelOut,
    collection_name="messages",
    prefix="messages",
    local_field="_id",
    foreign_field="user_id",
    )

    users_router = CRUDRouter(
        model=UserModel,
        model_out=UserModelOut,
        db=db,
        collection_name="users",
        lookups=[messages_lookup],
        prefix="/users",
        tags=["users"],
    )

Routes

---

The CRUDRouter will automatically build the following routes :

Route	Method	Description
/parents	GET	Get all documents
/parents	POST	Create a new document
/parents/{id}	GET	Get a document by id
/parents/{id}	PUT	Update a document by id
/parents/{id}	DELETE	Delete a document by id
/parents/{id}/childrens	GET	Get all childrens of a parent
/parents/{id}/childrens/{lookup_id}	GET	Get a child of a parent by id
/parents/{id}/childrens	POST	Create a new child document
/parents/{id}/childrens/{lookup_id}	PUT	Replace a child document by id and lookup_id
/parents/{id}/childrens/{lookup_id}	PATCH	Update a child document by id and lookup_id
/parents/{id}/childrens/{lookup_id}	DELETE	Delete a document by id

If you want to respect the RESTfull

Make sure to add an s to the end of prefix, so that the route will be /childrens instead of /children (which is not correct, I know, but you see the point here ).

OpenAPI Result

---

The CRUDRouter will also generate the OpenAPI schema for you, and document the routes for you.

If you are looking for a way to make the CRUDRouter work with an embed model, don't worry I got your back .

https://pierrod.github.io/fastapi-crudrouter-mongodb-doc/features/CRUDEmbed/