## Écrire des templates { #writing-templates }

Vous pouvez ensuite écrire un template dans `templates/item.html`, par exemple :

```jinja hl_lines="7"
{!../../docs_src/templates/templates/item.html!}
```

### Valeurs de contexte du template { #template-context-values }

Dans le HTML qui contient :

{% raw %}

```jinja
Item ID: {{ id }}
```

{% endraw %}

                        },
                        "summary": "Create Item",
                        "operationId": "create_item_items__post",
                        "requestBody": {
                            "content": {
                                "application/json": {
                                    "schema": {"$ref": "#/components/schemas/Item"}
                                }
                            },

                        },
                        "summary": "Update Item",
                        "operationId": "update_item_items__item_id__put",
                        "requestBody": {
                            "content": {
                                "application/json": {
                                    "schema": {"$ref": "#/components/schemas/Item"}
                                }
                            },

# ---------------
constraints.AssertFalse.message = {item} は false にしてください。
constraints.AssertTrue.message = {item} は true にしてください。
constraints.DecimalMax.message = {item} は {value} より小さくしてください。
constraints.DecimalMin.message = {item} は {value} より大きくしてください。
constraints.Digits.message = {item} は数値でなければなりません。(期待値: <数値>.<数値>)
constraints.Future.message = {item}は将来の値にする必要があります。
constraints.Max.message = {item} は {value} 以下にしてください。

from pydantic.v1 import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    size: float


class ItemV2(BaseModelV2):
    name: str
    description: str | None = None
    size: float


app = FastAPI()


@app.post("/items/", response_model=ItemV2)
async def create_item(item: Item):

 *
 * <p>Advantages compared to {@code double[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third
 *       edition, Item 17).
 *   <li>Has the value-based (not identity-based) {@link #equals}, {@link #hashCode}, and {@link
 *       #toString} behavior you expect.

 *
 * <p>Advantages compared to {@code int[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third
 *       edition, Item 17).
 *   <li>Has the value-based (not identity-based) {@link #equals}, {@link #hashCode}, and {@link
 *       #toString} behavior you expect.

          nextStart = offset;
          continue;
        }

        if (limit == 1) {
          // The limit has been reached, return the rest of the string as the
          // final item. This is tested after empty string removal so that
          // empty strings do not count towards the limit.
          end = toSplit.length();
          offset = -1;

Y si revisas todos los esquemas disponibles (JSON Schemas) en OpenAPI, verás que hay dos, uno `Item-Input` y uno `Item-Output`.

Para `Item-Input`, `description` **no es requerido**, no tiene un asterisco rojo.

Pero para `Item-Output`, `description` **es requerido**, tiene un asterisco rojo.

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image04.png">

def process_item(item: int | str):