Playwright.BrowserContext provides a way to operate multiple independent browser sessions.

If a page opens another page, e.g. with a window.open call, the popup will belong to the parent page's browser context.

Playwright allows creation of "incognito" browser contexts with the Playwright.Browser.new_context/1 function.

Example

# create a new "incognito" browser context:
{:ok, context} = Playwright.Browser.new_context(browser)

# create and use a new page within that context:
{:ok, page} = Playwright.BrowserContext.new_page(context)
{:ok, resp} = Playwright.Page.goto(page, "https://example.com")

# dispose the context once it's no longer needed:
Playwright.BrowserContext.close(context)

Regarding expect_event/5 and on/3

The first argument given to on/3 and expect_event/5 functions is the "owner" on which to bind the event.

The second argument is the event type.

The third argument is a callback function that will be executed when the event fires, and is passed an instance of Playwright.Runner.EventInfo.

Details for expect_event/5

Calls to expect_event/5 are blocking. These functions take a "trigger", execution of which is expected to result in the event being fired.

If the event does not fire within the timeout window, the call to expect_event/5 will timeout.

An optional "predicate" function may be provided, in which case the fired event will be sent to the predicate, which must return a "truthy" result in order for the expectation to be fulfilled.

{:ok, e } = BrowserContext.expect_event(context, :close, fn ->
  Page.close(page)
end)
assert %BrowserContext{} = e.target

Details for on/3

Calls to on/3 are non-blocking and register callbacks for the lifetime of the binding target.

BrowserContext.on(context, :close, fn e ->
  assert %BrowserContext{} = e.target
end)

Event types

The expect_event/5 and on/3 functions support the following event types:

• :background_page

  Emitted when a new background page is created in the context. The event target is a Playwright.Page.

  ...

  NOTE:

  • Only works with Chromium browser's persistent context.

• :close

  Emitted when the Playwright.BrowserContext is closed. The event target is a Playwright.BrowserContext. This might happen because of any of the following:

  • Browser context is closed.
  • Browser application is closed or crashed.
  • Playwright.Browser.close/1 is called.
  • Playwright.Page.close/1 is with the "owner page" for this context.

• :page

  Emitted when a new Playwright.Page is created within the context. The page may still be loading. The event target is a Playwright.Page. The event will also fire for popup pages. The earliest moment that a page is available is when it has navigated to the initial URL. For example, when opening a popup with window.open('http://example.com'), this event will fire when the network request to "http://example.com" is done and its response has started loading in the popup.

  BrowserContext.expect_event(context, :page, fn ->
    Page.click(page, "a[target=_blank]")
  end)

  NOTE:

  • Use Playwright.Page.wait_for_load_state/3 to wait until the page gets to a particular state (you should not need it in most cases).

• :request

  Emitted when a request is issued from any pages created through this context. The event target is a Playwright.Request. To only listen for requests from a particular page, use Playwright.Page.on/3 (for :request). In order to intercept and mutate requests, see route/4 or Playwright.Page.route/4.

• :request_failed

  Emitted when a request fails, for example by timing out. The event target is a Playwright.Request. To only listen for failed requests from a particular page, use Playwright.Page.on/3 (for :request_failed).

  NOTE:

  • HTTP error responses, such as 404 or 503, are still successful responses from HTTP standpoint. So, the request will complete with a :request_finished event and not with :request_failed.

• :request_finished

  Emitted when a request finishes successfully after downloading the response body. The event target is a Playwright.Request. For a successful response, the sequence of events is :request, :response and :request_finished. To listen for successful requests from a particular page, use Playwright.Page.on/3 (for :request_finished).

• :response

  Emitted when response status and headers are received for a request. The event target is a Playwright.Response. For a successful response, the sequence of events is :request, :response and :request_finished. To listen for response events from a particular page, use Playwright.Page.on/3 (for :response).

• :service_worker

  Emitted when new service worker is created in the context. The event target is a Playwright.Worker.

  NOTE:

  • Service workers are only supported on Chromium-based browsers.