Package com.microsoft.playwright

Interface Worker

All Known Implementing Classes:
WorkerImpl
public interface Worker
The Worker class represents a WebWorker. worker event is emitted on the page object to signal a worker creation. close event is emitted on the worker object when the worker is gone. 

 page.onWorker(worker -> {
   System.out.println("Worker created: " + worker.url());
   worker.onClose(worker1 -> System.out.println("Worker destroyed: " + worker1.url()));
 });
 System.out.println("Current workers:");
 for (Worker worker : page.workers())
   System.out.println("  " + worker.url());

  • Method Details

    • onClose

      void onClose(Consumer<Worker> handler)
      Emitted when this dedicated WebWorker is terminated.

    • offClose

      void offClose(Consumer<Worker> handler)
      Removes handler that was previously added with onClose(handler).

    • evaluate

      default Object evaluate(String expression)
      Returns the return value of expression.

      If the function passed to the Worker.evaluate() returns a Promise, then Worker.evaluate() would wait for the promise to resolve and return its value.

      If the function passed to the Worker.evaluate() returns a non-[Serializable] value, then Worker.evaluate() returns undefined. Playwright also supports transferring some additional values that are not serializable by JSON: -0, NaN, Infinity, -Infinity.

      Parameters:
      expression - JavaScript expression to be evaluated in the browser context. If the expression evaluates to a function, the function is automatically invoked.
      Since:
      v1.8

    • evaluate

      Object evaluate(String expression, Object arg)
      Returns the return value of expression.

      If the function passed to the Worker.evaluate() returns a Promise, then Worker.evaluate() would wait for the promise to resolve and return its value.

      If the function passed to the Worker.evaluate() returns a non-[Serializable] value, then Worker.evaluate() returns undefined. Playwright also supports transferring some additional values that are not serializable by JSON: -0, NaN, Infinity, -Infinity.

      Parameters:
      expression - JavaScript expression to be evaluated in the browser context. If the expression evaluates to a function, the function is automatically invoked.
      arg - Optional argument to pass to expression.
      Since:
      v1.8

    • evaluateHandle

      default JSHandle evaluateHandle(String expression)
      Returns the return value of expression as a JSHandle.

      The only difference between Worker.evaluate() and Worker.evaluateHandle() is that Worker.evaluateHandle() returns JSHandle.

      If the function passed to the Worker.evaluateHandle() returns a Promise, then Worker.evaluateHandle() would wait for the promise to resolve and return its value.

      Parameters:
      expression - JavaScript expression to be evaluated in the browser context. If the expression evaluates to a function, the function is automatically invoked.
      Since:
      v1.8

    • evaluateHandle

      JSHandle evaluateHandle(String expression, Object arg)
      Returns the return value of expression as a JSHandle.

      The only difference between Worker.evaluate() and Worker.evaluateHandle() is that Worker.evaluateHandle() returns JSHandle.

      If the function passed to the Worker.evaluateHandle() returns a Promise, then Worker.evaluateHandle() would wait for the promise to resolve and return its value.

      Parameters:
      expression - JavaScript expression to be evaluated in the browser context. If the expression evaluates to a function, the function is automatically invoked.
      arg - Optional argument to pass to expression.
      Since:
      v1.8

    • url

      String url()
      Since:
      v1.8

    • waitForClose

      default Worker waitForClose(Runnable callback)
      Performs action and waits for the Worker to close.
      Parameters:
      callback - Callback that performs the action triggering the event.
      Since:
      v1.10

    • waitForClose

      Worker waitForClose(Worker.WaitForCloseOptions options, Runnable callback)
      Performs action and waits for the Worker to close.
      Parameters:
      callback - Callback that performs the action triggering the event.
      Since:
      v1.10