324211 - setting parentURIContentListener throws Exception NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN Cannot modify properties of a WrappedNative

Status: RESOLVED INVALID

(Toolkit Graveyard :: Error Console, defect)

Description

[general]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051111 Firefox/1.5
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051111 Firefox/1.5

I've written an extension for FireFox 1.0.6 which captures URL events.  According to the "Mozilla Embedding FAQ - How do I watch/intercept a load before it happens?" 
http://developer.mozilla.org/en/docs/Mozilla_Embedding_FAQ:How_do_I...

The following code works in all other version including 1.0.6 but not in 1.5

This is a snippet of my code which is failing: 

 docShell = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
      .getInterface(Components.interfaces.nsIWebNavigation)
      .QueryInterface(Components.interfaces.nsIDocShell)
      .QueryInterface(Components.interfaces.nsIInterfaceRequestor);
  try {
    docShell.parentURIContentListener = uriListener;
  } catch (e) {
    consoleService.logStringMessage("Exception:" + e);
  }


Reproducible: Always

Steps to Reproduce:
1. Bring up the Java Console
2. Insert the following line in the evaluate text field as one line: 
var uriListener; var docShell = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor) .getInterface(Components.interfaces.nsIWebNavigation) .QueryInterface(Components.interfaces.nsIDocShell) .QueryInterface(Components.interfaces.nsIInterfaceRequestor); try { docShell.parentURIContentListener = uriListener; } catch (e) { Components.classes['@mozilla.org/consoleservice;1'].getService(Components.interfaces.nsIConsoleService).logStringMessage("Exception:" + e); }
}

3. Click evaluate

Actual Results:  
Exception:[Exception... "Cannot modify properties of a WrappedNative"  nsresult: "0x80570034 (NS_ERROR_XPC_CANT_MODIFY_PROP_ON_WN)"  location: "JS frame :: javascript: var uriListener; var docShell = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor) .getInterface(Components.interfaces.nsIWebNavigation) .QueryInterface(Components.interfaces.nsIDocShell) .QueryInterface(Components.interfaces.nsIInterfaceRequestor); try { docShell.parentURIContentListener = uriListener; } catch (e) { Components.classes['@mozilla.org/consoleservice;1'].getService(Components.interfaces.nsIConsoleService).logStringMessage("Exception:" + e); } :: <TOP_LEVEL> :: line 1"  data: no]

Expected Results:  
no exception thrown as seen in FireFox 1.0.6

Please fix this.  As an extension developer this is the only way to intercept URIs and to maintain backward compatibility.

Comment 1

[Dave Townsend [:mossop]]

The parentURIContentListener attribute has been removed from the docshell object. Please check bug 283108 for details and some info on what to use instead.

Comment 2

[rtrappman]

See also: https://bugzilla.mozilla.org/show_bug.cgi?id=428602