# CORS（跨域资源共享）

<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">CORS 或者「跨域资源共享」</a> 指浏览器中运行的前端拥有与后端通信的 JavaScript 代码，而后端处于与前端不同的「源」的情况。

## 源

源是协议（`http`，`https`）、域（`myapp.com`，`localhost`，`localhost.tiangolo.com`）以及端口（`80`、`443`、`8080`）的组合。

因此，这些都是不同的源：

* `http://localhost`
* `https://localhost`
* `http://localhost:8080`

即使它们都在 `localhost` 中，但是它们使用不同的协议或者端口，所以它们都是不同的「源」。

## 步骤

    util.concurrent tests under Guava.

    The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see
    https://groups.google.com/g/google-web-toolkit-contributors/c/CqYH59Dt_rQ/m/uVGW1QdUsXUJ
    for details.

    The summary is that it ignores one file in favor of the other.
    util.concurrent, like nearly all our packages, has two .gwt.xml files: one

ng.org/dl/#stable) ```sh go install github.com/minio/minio@latest ``` The MinIO deployment starts using default root credentials `minioadmin:minioadmin`. You can test the deployment using the MinIO Console, an embedded web-based object browser built into MinIO Server. Point a web browser running on the host machine to <http://127.0.0.1:9000> and log in with the root credentials. You can use the Browser to create buckets, upload objects, and browse the contents of the MinIO server. You can also connect...

/// tip

To know more about each status code and which code is for what, check the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Status" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> documentation about HTTP status codes</a>.

///

## Shortcut to remember the names

Let's see the previous example again:

Então, você ainda pode precisar usar modelos Pydantic.

Mas se você tem um monte de dataclasses por aí, este é um truque legal para usá-las para alimentar uma API web usando FastAPI. 🤓

///

## Dataclasses em `response_model`

Você também pode usar `dataclasses` no parâmetro `response_model`:

```Python hl_lines="1  7-13  19"
{!../../docs_src/dataclasses/tutorial002.py!}

もし Web API の代わりにターミナルで使用する<abbr title="Command Line Interface">CLI</abbr>アプリを構築する場合は、<a href="https://typer.tiangolo.com/" class="external-link" target="_blank">**Typer**</a>を確認してください。

**Typer**は FastAPI の弟分です。そして、**CLI 版 の FastAPI**を意味しています。

## 必要条件

FastAPI は巨人の肩の上に立っています。

📊 ⚪️➡️ 📨 🛎 🗜 ⚙️ "📻 🆎" `application/x-www-form-urlencoded`.

✋️ 🕐❔ 📨 🔌 📁, ⚫️ 🗜 `multipart/form-data`. 👆 🔜 ✍ 🔃 🚚 📁 ⏭ 📃.

🚥 👆 💚 ✍ 🌖 🔃 👉 🔢 &amp; 📨 🏑, 👳 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">🏇</abbr> 🕸 🩺 <code>POST</code></a>.

///

/// warning

// Standard path where an app would find cross domain policy information.
const crossDomainXMLEntity = "/crossdomain.xml"

// A cross-domain policy file is an XML document that grants a web client, such as Adobe Flash Player
// or Adobe Acrobat (though not necessarily limited to these), permission to handle data across domains.
// When clients request content hosted on a particular source domain and that content make requests

///

## Benutzerdefinierte Header

Beachten Sie, dass benutzerdefinierte proprietäre Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix 'X-'</a> hinzugefügt werden können.

///

## Custom Headers

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.