# Extra Models

Continuing with the previous example, it will be common to have more than one related model.

This is especially the case for user models, because:

* The **input model** needs to be able to have a password.
* The **output model** should not have a password.
* The **database model** would probably need to have a hashed password.

/// danger

Never store user's plaintext passwords. Always store a "secure hash" that you can then verify.

This ADR does not specify the owner of this new architecture module. However, as a separate module, it can be assigned ownership independently of the other core services.

## Status

ACCEPTED

## Consequences

- Introduce the module and move the services and their implementations.

  <modelVersion>4.0.0</modelVersion>

  <groupId>inheritance</groupId>
  <artifactId>parent</artifactId>
  <version>11-SNAPSHOT</version>

  <name>Model inheritance test parent: module path != artifactId</name>

  <modules>
    <module>child</module>
  </modules>

  <!-- 5 URLs in the pom will be inherited with path added -->
  <url>http://www.apache.org/</url>
  <scm>

## Composition by architecture modules

Each [architecture module and platform](platforms.md) can contribute code to any of the elements.
Not every module contributes to every element.

# Modelos de Parâmetros de Cookie

Se você possui um grupo de **cookies** que estão relacionados, você pode criar um **modelo Pydantic** para declará-los. 🍪

Isso lhe permitiria **reutilizar o modelo** em **diversos lugares** e também declarar validações e metadata para todos os parâmetros de uma vez. 😎

/// note | Nota

Isso é suportado desde a versão `0.115.0` do FastAPI. 🤓

///

/// tip | Dica

    <version>11-SNAPSHOT</version>
  </parent>

  <artifactId>child-artifact-id</artifactId>
  <name>Model inheritance test parent: module directory != artifactId</name>
  <description>
    artifactId == "child-artifact-id"
    but expect path on SCM and site == "child"
    feature: support "project.directory" property, ressembling future model addition of "directory" element along "artifactId"
  </description>

  <properties>

  <artifactId>child-artifact-id</artifactId>
  <version>11-SNAPSHOT</version>
  <name>Model inheritance test parent: module directory != artifactId</name>
  <description>
    artifactId == "child-artifact-id"
    but expect path on SCM and site == "child"
    feature: support "project.directory" property, ressembling future model addition of "directory" element along "artifactId"
  </description>

# Cookie Parameter Models

If you have a group of **cookies** that are related, you can create a **Pydantic model** to declare them. 🍪

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

/// tip

This same technique applies to `Query`, `Cookie`, and `Header`. 😎

///

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Model(BaseModel):
    pass


class Model2(BaseModel):
    a: Model


class Model3(BaseModel):
    c: Model
    d: Model2


@app.get("/", response_model=Model3)
def f():
    return {"c": {}, "d": {"a": {}}}


client = TestClient(app)


def test_get_api_route():

## Nested Models

Each attribute of a Pydantic model has a type.

But that type can itself be another Pydantic model.

So, you can declare deeply nested JSON "objects" with specific attribute names, types and validations.

All that, arbitrarily nested.

### Define a submodel

For example, we can define an `Image` model:

//// tab | Python 3.10+