Eğer tarayıcınızda <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a> sayfasını açarsanız, şuna benzer güzel bir HTTP hatası ile karşılaşırsınız:

```JSON
{
  "detail": [
    {
      "type": "int_parsing",
      "loc": [
        "path",
        "item_id"
      ],
      "msg": "Input should be a valid integer, unable to parse string as an integer",
      "input": "foo"
    }

Якщо ж відкрити у браузері посилання <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, то побачимо цікаву HTTP-помилку:

```JSON
{
  "detail": [
    {
      "type": "int_parsing",
      "loc": [
        "path",
        "item_id"
      ],
      "msg": "Input should be a valid integer, unable to parse string as an integer",
      "input": "foo"
    }

ここで、クエリパラメータ `needy` は `str` 型の必須のクエリパラメータです

以下のURLをブラウザで開くと:

```
http://127.0.0.1:8000/items/foo-item
```

...必須のパラメータ `needy` を加えなかったので、以下の様なエラーが表示されます:

```JSON
{
    "detail": [
        {
            "loc": [
                "query",
                "needy"
            ],
            "msg": "field required",
            "type": "value_error.missing"
        }
    ]
}

                _src = _src.deferred;
                name = _src.dec_ndr_string();

            }
        }
    }

    /**
     * RPC message for retrieving server information at various detail levels.
     */
    public static class ServerGetInfo extends DcerpcMessage {

        @Override
        public int getOpnum() {
            return 0x15;
        }

        /**

            [*] https://code.google.com/p/google-web-toolkit/wiki/ResourceOracle#When_multiple_PathPrefix_es_have_the_same_path
                https://code.google.com/p/google-web-toolkit/issues/detail?id=7581
            -->
          <execution>
            <id>gwt-test</id>
            <goals>
              <goal>test</goal>
            </goals>
            <configuration>

///

## Validation de données

Si vous allez sur <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, vous aurez une belle erreur HTTP :

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"
            ],
            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]

	"strconv"
	"strings"
	"sync"
	"syscall"
)

func adbRun(args string) (int, error) {
	// The exit code of adb is often wrong. In theory it was fixed in 2016
	// (https://code.google.com/p/android/issues/detail?id=3254), but it's
	// still broken on our builders in 2023. Instead, append the exitcode to
	// the output and parse it from there.
	filter, exitStr := newExitCodeFilter(os.Stdout)
	args += "; echo -n " + exitStr + "$?"

```

and it will work correctly, together with all the other *path operations* added with `app.include_router()`.

/// info | Very Technical Details

**Note**: this is a very technical detail that you probably can **just skip**.

---

The `APIRouter`s are not "mounted", they are not isolated from the rest of the application.

///

## データバリデーション

しかしブラウザで <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a> を開くと、次のHTTPエラーが表示されます:

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"
            ],
            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]

The document is not comprehensive.
</p>

<p>
The assembler is based on the input style of the Plan 9 assemblers, which is documented in detail
<a href="https://9p.io/sys/doc/asm.html">elsewhere</a>.
If you plan to write assembly language, you should read that document although much of it is Plan 9-specific.