browsingContext.userPromptOpened event

Event data

The params field in the event notification is an object with the following fields:

context

A string that contains the ID of the context that has the user prompt.

defaultValue Optional

A string that contains the default value of the prompt() dialog. This field is included only when the type field value is "prompt" and the default value is not null.

handler

A string that indicates how the prompt will be handled. The behavior is set by the unhandledPromptBehavior capability for the session, or overridden per user context with browser.createUserContext. It has one of the following values:

• "accept": The browser will accept the prompt.
• "dismiss": The browser will dismiss the prompt.
• "ignore": The browser will leave the prompt open for the client to close using browsingContext.handleUserPrompt.

message

A string that contains the message displayed in the prompt.

type

A string that indicates the kind of user prompt that opened. It has one of the following values:

• "alert": An alert() dialog.
• "beforeunload": A dialog shown by the beforeunload event.
• "confirm": A confirm() dialog.
• "prompt": A prompt() dialog.

Examples

Receiving an event when an alert opens

With a WebDriver BiDi connection, suppose a session is created via session.new with the default field of the unhandledPromptBehavior capability set to "ignore" so that the browser leaves dialogs open for the client to handle. Also assume that a subscription to browsingContext.userPromptOpened is active.

Suppose a page calls alert("Are you sure?"). The browser sends the following notification:

{
  "type": "event",
  "method": "browsingContext.userPromptOpened",
  "params": {
    "context": "93ee5bd6-d256-4608-a002-9a8995cc0e5f",
    "handler": "ignore",
    "message": "Are you sure?",
    "type": "alert"
  }
}

Receiving an event when a prompt with a default value opens

Using the same connection, session, and subscription as in the first example, suppose a page calls prompt("Enter your name:", "Jane Doe").

The browser sends the following notification:

{
  "type": "event",
  "method": "browsingContext.userPromptOpened",
  "params": {
    "context": "93ee5bd6-d256-4608-a002-9a8995cc0e5f",
    "handler": "ignore",
    "message": "Enter your name:",
    "type": "prompt",
    "defaultValue": "Jane Doe"
  }
}

Receiving an event when a beforeunload dialog opens

Using the same connection, session, and subscription as in the first example, suppose the client uses the browsingContext.navigate command to navigate away from a page with a beforeunload event handler that prompts for confirmation before leaving the page.

When the dialog opens, before the navigation completes, the browser sends the following notification:

{
  "type": "event",
  "method": "browsingContext.userPromptOpened",
  "params": {
    "context": "93ee5bd6-d256-4608-a002-9a8995cc0e5f",
    "handler": "ignore",
    "message": "This page is asking you to confirm that you want to leave — information you've entered may not be saved.",
    "type": "beforeunload"
  }
}

The session's unhandledPromptBehavior capability setting also applies to the handling of the beforeunload dialogs, so the notification in this example reports a handler value of "ignore". The dialog stays open until the client closes it with the browsingContext.handleUserPrompt command.

Specifications

Browser compatibility

See also

• browsingContext.userPromptClosed event
• browsingContext.handleUserPrompt command
• session.subscribe command