/// note

`data` and `raw_data` are mutually exclusive. You can only set one of them on each `ServerSentEvent`.

///

## Resuming with `Last-Event-ID` { #resuming-with-last-event-id }

When a browser reconnects after a connection drop, it sends the last received `id` in the `Last-Event-ID` header.

You can read it as a header parameter and use it to resume the stream from where the client left off:

        What is the problem, question, or error?

        Write a short description telling me what you are doing, what you expect to happen, and what is currently happening.
      placeholder: |
        * Open the browser and call the endpoint `/`.
        * It returns a JSON with `{"Hello": "World"}`.
        * But I expected it to return `{"Hello": "Sara"}`.
    validations:
      required: true
  - type: dropdown
    id: os

## Caveat

*Applications that use direct S3 API will work fine, however interactive users uploading content using (when POSTing to the presigned URL an app generates) a popup becomes visible on browser to provide client certs, you would have to manually cancel and continue. This may be annoying to use but there is no workaround for now.*

## Explore Further

このアプリには `/api/v1` のパスプレフィックスを付与するプロキシがあるため、フロントエンドは `/api/v1/openapi.json` から取得する必要があります。

```mermaid
graph LR

browser("Browser")
proxy["Proxy on http://0.0.0.0:9999/api/v1/app"]
server["Server on http://127.0.0.1:8000/app"]

browser --> proxy
proxy --> server
```

/// tip | 豆知識

IP `0.0.0.0` は、そのマシン/サーバーで利用可能なすべての IP で待ち受けることを意味する表現として一般的に使われます。

///

,a.each(l,function(a,b){if(i=k.indexOf(b)>-1)return!1}),i}),i||(a.formUtils.warn("Trying to upload a file with mime type "+k+" which is not allowed"),e(this,"wrongFileType",l.join(", "),h))),i}return a.formUtils.warn("FileReader not supported by browser, will check file extension"),a.formUtils.validators.validate_extension.validatorFunction(b,f,g,h)},errorMessage:"",errorMessageKey:"wrongFileType"}),a.formUtils.addValidator({name:"extension",validatorFunction:function(b,c,f,g){var h=!0,i=this,j=d(c);return...

因此，（在浏览器中运行的）前端会尝试访问 `/openapi.json`，但无法获取 OpenAPI 模式。

因为我们的应用使用了路径前缀为 `/api/v1` 的代理，前端需要从 `/api/v1/openapi.json` 获取 OpenAPI 模式。

```mermaid
graph LR

browser("Browser")
proxy["Proxy on http://0.0.0.0:9999/api/v1/app"]
server["Server on http://127.0.0.1:8000/app"]

browser --> proxy
proxy --> server
```

/// tip | 提示

IP `0.0.0.0` 通常表示程序监听该机器/服务器上的所有可用 IP。

///

{* ../../docs_src/query_params/tutorial005_py310.py hl[6:7] *}

Here the query parameter `needy` is a required query parameter of type `str`.

If you open in your browser a URL like:

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

...without adding the required parameter `needy`, you will see an error like:

```JSON
{
  "detail": [
    {

/* Right to left languages */
code {
  direction: ltr;
  display: inline-block;
}

.illustration {
  margin-top: 2em;
  margin-bottom: 2em;
}

/* Screenshots */
/*
Simulate a browser window frame.
Inspired by Termynal's CSS tricks with modifications
*/

.screenshot {
  display: block;
  background-color: #d3e0de;
  border-radius: 4px;
  padding: 45px 5px 5px;
  position: relative;

    private static Stream<Arguments> provideNamesForWriteTest() {
        return Stream.of(Arguments.of("SERVER", 0x20, "CLIENT", 0x00), Arguments.of("WORKSTATION", 0x00, "USER", 0x03),
                Arguments.of("DOMAIN", 0x1B, "BROWSER", 0x1D), Arguments.of("A", 0x20, "B", 0x00),
                Arguments.of("VERYLONGNAMETEST", 0x20, "ANOTHERLONGNAME", 0x00));
    }

    @Test

# Request Body { #request-body }

When you need to send data from a client (let's say, a browser) to your API, you send it as a **request body**.

A **request** body is data sent by the client to your API. A **response** body is the data your API sends to the client.