We could do better.

We can declare a `UserBase` model that serves as a base for our other models. And then we can make subclasses of that model that inherit its attributes (type declarations, validation, etc).

All the data conversion, validation, documentation, etc. will still work as normally.

That way, we can declare just the differences between the models (with plaintext `password`, with `hashed_password` and without password):

                                    (problemsService as InternalProblems).internalReporter.create {
                                        id("invalid-dependency", "Property cannot carry dependency", GradleCoreProblemGroup.validation().property())
                                        contextualLabel("Property '$propertyName' cannot carry a dependency on $dependency as these are not yet supported.")
                                        severity(Severity.ERROR)

With `Form` you can declare the same configurations as with `Body` (and `Query`, `Path`, `Cookie`), including validation, examples, an alias (e.g. `user-name` instead of `username`), etc.

!!! info
    `Form` is a class that inherits directly from `Body`.

!!! tip

  // Multiple endpoints which use the same hostname should be considered
  // fungible (e.g. multiple A values in DNS). Must be lowercase and pass DNS
  // Label (RFC 1123) validation.
  // +optional
  optional string hostname = 3;

  // targetRef is a reference to a Kubernetes object that represents this
  // endpoint.
  // +optional
  optional .k8s.io.api.core.v1.ObjectReference targetRef = 4;

                `embedded-kotlin`
            }

            $repositoriesBlock

            tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {
                // Work around JVM validation issue: https://youtrack.jetbrains.com/issue/KT-66919
                jvmTargetValidationMode = org.jetbrains.kotlin.gradle.dsl.jvm.JvmTargetValidationMode.WARNING
            }

            """
        )

  // Multiple endpoints which use the same hostname should be considered
  // fungible (e.g. multiple A values in DNS). Must be lowercase and pass DNS
  // Label (RFC 1123) validation.
  // +optional
  optional string hostname = 3;

  // targetRef is a reference to a Kubernetes object that represents this
  // endpoint.
  // +optional
  optional k8s.io.api.core.v1.ObjectReference targetRef = 4;

the schema must be added here, otherwise istioctl users will see errors.
Once the schema file is updated, run:

```bash
$ make operator-proto
```

This will regenerate the Go structs used for schema validation.

## Step 4. Update the generated manifests

Tests of istioctl use the auto-generated manifests to ensure that the istioctl binary has the correct version of the charts.
To regenerate the manifests, run:

```bash

These handlers are in charge of returning the default JSON responses when you `raise` an `HTTPException` and when the request has invalid data.

You can override these exception handlers with your own.

### Override request validation exceptions

When a request contains invalid data, **FastAPI** internally raises a `RequestValidationError`.

And it also includes a default exception handler for it.

使用上面的任何方法，它在 `/docs` 中看起来都是这样的:

<img src="/img/tutorial/body-fields/image01.png">

## 技术细节

关于 `example` 和 `examples`...

JSON Schema在最新的一个版本中定义了一个字段 <a href="https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.5" class="external-link" target="_blank">`examples`</a> ，但是 OpenAPI 基于之前的一个旧版JSON Schema，并没有 `examples`.

Cela vous donne beaucoup de flexibilité. Vous pouvez retourner n'importe quel type de données, surcharger n'importe quelle déclaration ou validation de données.

## Utiliser le `jsonable_encoder` dans une `Response`