Method Override Plugin

Use MethodOverrideHandlerPlugin to override the HTTP method of a POST request with a query parameter, so HTML forms can invoke PUT, PATCH, and DELETE procedures.

How It Works

HTML forms only support the GET and POST methods. When a POST request carries a method query parameter with an allowed value, the plugin routes the request as if it used that method and removes the parameter before input decoding. Values outside the allowed list are ignored and the request is processed as a regular POST.

<form method="post" action="/api/todos/1?method=DELETE">
  <button>Delete todo</button>
</form>

Setup

import { OpenAPIHandler } from '@orpc/openapi/fetch'
import { MethodOverrideHandlerPlugin } from '@orpc/server/plugins'

const handler = new OpenAPIHandler(router, {
  plugins: [
    new MethodOverrideHandlerPlugin({
      /**
       * The query parameter carrying the override method.
       *
       * @default 'method'
       */
      param: 'method',

      /**
       * The methods a POST request may be overridden to.
       *
       * GET and HEAD are excluded by default because they switch input decoding
       * from the request body to the query string and widen the CSRF surface.
       *
       * @default ['PUT', 'PATCH', 'DELETE']
       */
      methods: ['PUT', 'PATCH', 'DELETE'],
    }),
  ],
})

Learn More

For implementation details, see the source code.