Non-standard
 
      This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
The mozbrowsershowmodalprompt event is fired when the content of a browser <iframe> calls the window.alert(), window.confirm(), or window.prompt() methods.
General info
- Specification
 - Non standard
 - Interface
 CustomEvent- Bubbles
 - Yes
 - Cancelable
 - Yes
 - Target
 <iframe>- Default Action
 - None
 
Properties
| Property | Type | Description | 
|---|---|---|
target Read only  |  
    EventTarget |  
    The browser iframe | 
type Read only  |  
    DOMString |  
    The type of event. | 
bubbles Read only  |  
    boolean |  
    Does the event normally bubble? | 
cancelable Read only  |  
    boolean |  
    Is it possible to cancel the event? | 
details Read only  |  
    Object |  
    A custom object | 
details
The details property is an anonymous JavaScript object with the following properties:
- promptType
 - A 
DOMStringdefining the type of the prompt. It can bealert,confirm, orprompt. - title
 - A 
DOMStringrepresenting the title of the prompt. - message
 - A 
DOMStringrepresenting the value passed to thewindow.alert(),window.confirm(), orwindow.prompt()methods within the browser<iframe>'s content. - returnValue
 - A 
DOMStringrepresenting the return value for thewindow.prompt()methods. This should be set by the embedder. - unblock()
 - A function to be called when the 
iframeis unblocked. Note that if the embedder callspreventDefault()on this event, theiframeis blocked untilunblock()is called. 
Obsolete properties of details
- msg_name
 - A string representing the type of message. For that event, it's always 
showmodalprompt. - initialValue
 - A string representing the initial value for the 
window.prompt()methods. 
Example
var browser = document.querySelector("iframe");
browser.addEventListener("mozbrowsershowmodalprompt", function( event ) {
  console.log("Asking for prompt:" + JSON.stringify(event.detail));
});
Related Events
mozbrowserasyncscrollmozbrowserclosemozbrowsercontextmenumozbrowsererrormozbrowsericonchangemozbrowserloadendmozbrowserloadstartmozbrowserlocationchangemozbrowseropenwindowmozbrowsersecuritychangemozbrowsertitlechangemozbrowserusernameandpasswordrequired