class WebSocketRecorder(
  private val name: String,
) : WebSocketListener() {
  private val events = LinkedBlockingQueue<Any>()
  private var delegate: WebSocketListener? = null

  /** Sets a delegate for handling the next callback to this listener. Cleared after invoked.  */
  fun setNextEventDelegate(delegate: WebSocketListener?) {
    this.delegate = delegate
  }

  override fun onOpen(
    webSocket: WebSocket,
    response: Response,

				// not as optimal but at least always safe to do.
				runtime.UnlockOSThread()
			}
		}()

		return toRun()
	}

	var wg sync.WaitGroup
	wg.Add(1)

	// Start the callback in a new green thread so that if we later fail
	// to switch the namespace back to the original one, we can safely
	// leave the thread locked to die without a risk of the current thread

                this.endDate = this.oldEndDate.clone();
            }

            //if a new date range was selected, invoke the user callback function
            if (!this.startDate.isSame(this.oldStartDate) || !this.endDate.isSame(this.oldEndDate))
                this.callback(this.startDate.clone(), this.endDate.clone(), this.chosenLabel);

            //if picker is attached to a text input, update it

   * exception.
   *
   * @throws IllegalStateException when the call has already been executed.
   */
  fun enqueue(responseCallback: Callback)

  /** Cancels the request, if possible. Requests that are already complete cannot be canceled. */
  fun cancel()

  /**

## Authorization Flow

- Visit <http://localhost:8080>, login will direct the user to the Google OAuth2 Auth URL to obtain a permission grant.
- The redirection URI (callback handler) receives the OAuth2 callback, verifies the state parameter, and obtains a Token.
- Using the id_token the callback handler further talks to Google OAuth2 Token URL to obtain an JWT id_token.

	select {
	case s.Requests <- b:
		return nil
	case <-s.ctx.Done():
		return context.Cause(s.ctx)
	}
}

// Results returns the results from the remote server one by one.
// If any error is returned by the callback, the stream will be canceled.
// If the context is canceled, the stream will be canceled.
func (s *Stream) Results(next func(b []byte) error) (err error) {
	done := false
	defer func() {
		if s.cancel != nil {

        /**
         * @param op The option of condition to be set up. (NotNull)
         */
        void callback(OP op);
    }

    @FunctionalInterface
    public interface OperatorCall<CA extends EsAbstractConditionAggregation> {

        void callback(CA query);
    }

 */
package okhttp3

import java.io.IOException
import java.util.concurrent.TimeUnit

/**
 * Records received HTTP responses so they can be later retrieved by tests.
 */
class RecordingCallback : Callback {
  private val responses = mutableListOf<RecordedResponse>()

  @Synchronized
  override fun onFailure(
    call: Call,
    e: IOException,
  ) {

    }

    protected void writeJsonResponse(final int status, final String body) {
        final String callback = LaRequestUtil.getOptionalRequest().map(req -> req.getParameter("callback")).orElse(null);
        final boolean isJsonp = ComponentUtil.getFessConfig().isApiJsonpEnabled() && StringUtil.isNotBlank(callback);

        final HttpServletResponse response = LaResponseUtil.getResponse();
        response.setStatus(status);

///

### 添加回调路由

至此，在上文创建的回调路由里就包含了*回调路径操作*（外部开发者要在外部 API 中实现）。

现在使用 API *路径操作装饰器*的参数 `callbacks`，从回调路由传递属性 `.routes`（实际上只是路由/路径操作的**列表**）：

```Python hl_lines="36"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip | "提示"

注意，不能把路由本身（`invoices_callback_router`）传递给 `callback=`，要传递 `invoices_callback_router.routes` 中的 `.routes` 属性。

///

### 查看文档