Package com.microsoft.playwright

Interface Worker

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());
 

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Worker.WaitForCloseOptions

Method Summary

Modifier and Type	Method	Description
default Object	evaluate(String expression)	Returns the return value of expression.
Object	evaluate(String expression, Object arg)	Returns the return value of expression.
default JSHandle	evaluateHandle(String expression)	Returns the return value of expression as a JSHandle.
JSHandle	evaluateHandle(String expression, Object arg)	Returns the return value of expression as a JSHandle.
void	offClose(Consumer<Worker> handler)	Removes handler that was previously added with onClose(handler).
void	onClose(Consumer<Worker> handler)	Emitted when this dedicated WebWorker is terminated.
String	url()
Worker	waitForClose(Worker.WaitForCloseOptions options, Runnable callback)	Performs action and waits for the Worker to close.
default Worker	waitForClose(Runnable callback)	Performs action and waits for the Worker to close.

Method Detail

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