# CORS Middleware

## Main

The CORS middleware allows you to enable or disable [Cross-origin resource sharing](https://en.wikipedia.org/wiki/Cross-origin_resource_sharing). This way, you can protect your endpoints from being requested from unknown origins or undesired origins.

### Usage

The usage of CORS middleware is quiet similar to other Mandarine modules, it is done through the use of Decorators.

**Syntax:**

`@Cors(corsOptions:` [`Mandarine.MandarineMVC.CorsMiddlewareOption`](https://doc.deno.land/https/raw.githubusercontent.com/mandarineorg/mandarinets/master/mvc-framework/mandarine-mvc.ns.ts#MandarineMvc.CorsMiddlewareOption)`)`

**Interface (**[MandarineMvc](https://doc.deno.land/https/raw.githubusercontent.com/mandarineorg/mandarinets/master/mvc-framework/mandarine-mvc.ns.ts#MandarineMvc).[CorsMiddlewareOption](https://doc.deno.land/https/raw.githubusercontent.com/mandarineorg/mandarinets/master/mvc-framework/mandarine-mvc.ns.ts#MandarineMvc.CorsMiddlewareOption))**:**

* `origin`
  * Declares the valid origins. It can be a **string,** a **RegExp,** or an array of both **string & RegExp** for multiple origins.
  * **Default**: `*`
* `methods`
  * Methods allowed
  * **Default**: `["GET", "HEAD", "PUT", "PATCH", "POST", "DELETE"]`
* `allowedHeaders`
  * List of headers to be added to `access-control-request-headers`
* `exposedHeaders`
  * List of headers to be added to `accessl-control-expose-headers`
* `credentials`
  * Boolean value for header `access-control-allow-credentials`
* `maxAge`
  * Value for header `access-control-max-age`
* `optionsSuccessStatus`
  * Http response code for when CORS has been accepted.
  * **Default**: 204

## Basic Usage

**At** [**Controller**](https://mandarineframework.gitbook.io/mandarine-ts/mandarine-mvc/controllers) **level:**

```typescript
import { Controller, GET, Cors } from "https://deno.land/x/mandarinets/mod.ts";

@Controller('/api')
@Cors({ origin: "https://myorigin.com" })
export class MyApi {

    @GET('/hello')
    public handler() {
        return "hello";
    }

}
```

**At** [**Route**](https://mandarineframework.gitbook.io/mandarine-ts/mandarine-mvc/controllers/using-routes-and-http-handlers) **level**

```typescript
import { Controller, GET, Cors } from "https://deno.land/x/mandarinets/mod.ts";

@Controller('/api')
export class MyApi {

    @GET('/hello')
    @Cors({ origin: "https://myorigin.com" })
    public handler() {
        return "hello";
    }
    
}
```