## JavaScript-only settings { #javascript-only-settings }

Swagger UI also allows other configurations to be **JavaScript-only** objects (for example, JavaScript functions).

FastAPI also includes these JavaScript-only `presets` settings:

```JavaScript
presets: [
    SwaggerUIBundle.presets.apis,
    SwaggerUIBundle.SwaggerUIStandalonePreset
]

## Self-hosting JavaScript and CSS for docs { #self-hosting-javascript-and-css-for-docs }

Self-hosting the JavaScript and CSS could be useful if, for example, you need your app to keep working even while offline, without open Internet access, or in a local network.

If you go to the **API docs UI** at `/docs` you will be able to see the **documentation** for cookies for your *path operations*.

But even if you **fill the data** and click "Execute", because the docs UI works with **JavaScript**, the cookies won't be sent, and you will see an **error** message as if you didn't write any values.

    }

    public void test_execute_differentScriptTypes() {
        // Test different script types
        Object result = jobExecutor.execute("javascript", "console.log('test')");
        assertEquals("Executed: javascript console.log('test')", result);

        result = jobExecutor.execute("python", "print('test')");
        assertEquals("Executed: python print('test')", result);

<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">CORS or "Cross-Origin Resource Sharing"</a> refers to the situations when a frontend running in a browser has JavaScript code that communicates with a backend, and the backend is in a different "origin" than the frontend.

## Origin { #origin }

    * une validation même pour les objets <abbr title="JavaScript Object Notation">JSON</abbr> profondément imbriqués.
* <abbr title="aussi connu sous le nom de : serialization, parsing, marshalling">Une conversion</abbr> des données d'entrée : venant du réseau et allant vers les données et types de Python, permettant de lire :
    * le <abbr title="JavaScript Object Notation">JSON</abbr>.

application/x-compress         z                # Gzip and Tar file
application/x-hdf              hdf              # NCSA HDF
application/x-ica              ica              # WinFrames
application/x-javascript       js               # Javascript
application/x-latex            latex            # Latex File
application/x-mif              mif              #
application/x-netcdf           nc cdf           #

Or you might have any other way to communicate with the WebSocket endpoint.

---

But for this example, we'll use a very simple HTML document with some JavaScript, all inside a long string.

This, of course, is not optimal and you wouldn't use it for production.

In production you would have one of the options above.

Стиль написания кода с `async` и `await` появился в языке Python относительно недавно.

Но он сильно облегчает работу с асинхронным кодом.

Ровно такой же синтаксис (ну или почти такой же) недавно был включён в современные версии JavaScript (в браузере и NodeJS).

До этого поддержка асинхронного кода была реализована намного сложнее, и его было труднее воспринимать.

Mas ele faz o trabalho com código assíncrono muito mais fácil.

Essa mesma sintaxe (ou quase a mesma) foi também incluída recentemente em versões modernas do JavaScript (no navegador e NodeJS).

Mas antes disso, controlar código assíncrono era bem mais complexo e difícil.