Error Console

This page is part of the extension development documentation project.

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Note: development documentation is in process of being moved to Mozilla Development Center (MDC).

You can print information to JavaScript Console using the following method:

1. Declare a variable (global if you're scripting your own window or your object's member if you're overlaying an existing window):

   var gConsoleService = Components.classes['@mozilla.org/consoleservice;1']
                       .getService(Components.interfaces.nsIConsoleService);

   (note, that you can use toJavaScriptConsole() function to open JavaScript console on startup)

2. Define a function:

   function myExt_logMessage(aMessage) {
     gConsoleService.logStringMessage('My extension: ' + aMessage);
   }

3. Use it like here:

   myExt_logMessage("Initialized.");

See also: Viewing dump() output, Using Console service.