nsISupports
Last changed in Gecko 19 (Firefox 19 / Thunderbird 19 / SeaMonkey 2.16)Implemented by: @mozilla.org/consoleservice;1
as a service:
var consoleService = Components.classes["@mozilla.org/consoleservice;1"] .getService(Components.interfaces.nsIConsoleService);
Method overview
void getMessageArray([array, size_is(count)] out nsIConsoleMessage messages, out uint32_t count); Obsolete since Gecko 19void getMessageArray( [optional] out uint32_t count, [retval, array, size_is(count)] out nsIConsoleMessage messages); |
void logMessage(in nsIConsoleMessage message); |
void logStringMessage(in wstring message); |
void registerListener(in nsIConsoleListener listener); |
void reset(); |
void unregisterListener(in nsIConsoleListener listener); |
Methods
getMessageArray()
To obtain an array of all logged messages.
Obsolete since Gecko 19 (Firefox 19 / Thunderbird 19 / SeaMonkey 2.16)
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
void getMessageArray( [array, size_is(count)] out nsIConsoleMessage messages, out PRUint32 count );
Parameters
messages
- An array of logged messages.
count
- The number of messages in the array. If no messages are logged, this function will return a count of 0, but allocating a placeholder word for messages, showing as a 0-length array when called from the script.
void getMessageArray( [optional] out PRUint32 count, [retval, array, size_is(count)] out nsIConsoleMessage messages );
Parameters
count
- The number of messages in the array. If no messages are logged, this function will return a count of 0, but allocating a placeholder word for messages, showing as a 0-length array when called from the script.
logMessage()
void logMessage( in nsIConsoleMessage message );
Parameters
message
- The
nsIConsoleMessage
to log.
logStringMessage()
A convenient method for logging simple messages.
void logStringMessage( in wstring message );
Parameters
message
- The string to log.
registerListener()
Registers a listener, to notify when an error is logged.
void registerListener( in nsIConsoleListener listener );
Parameters
listener
- The
nsIConsoleListener
to add.
reset()
To clear the message buffer (For example, for privacy reasons):
void reset();
Parameters
None.
reset,
so they too can clear their message buffers. (This also works before Gecko 19.)unregisterListener()
Deregisters a listener.
void unregisterListener( in nsIConsoleListener listener );
Parameters
listener
- The
nsIConsoleListener
to remove.
Examples
Retrieving the message array
To retrieve the message array in Gecko prior to version 19:
function getConsoleMessageArray() { var consoleService = Components.classes["@mozilla.org/consoleservice;1"] .getService(Components.interfaces.nsIConsoleService); var array = {}; consoleService.getMessageArray(array, {}); return array.value; }
To retrieve the message array in Gecko 19 or later:
function getConsoleMessageArray() { var consoleService = Components.classes["@mozilla.org/consoleservice;1"] .getService(Components.interfaces.nsIConsoleService); return consoleService.getMessageArray(); }
To retrieve the message array in a compatible way:
function getConsoleMessageArray() { var consoleService = Components.classes["@mozilla.org/consoleservice;1"] .getService(Components.interfaces.nsIConsoleService); var array = {}; return consoleService.getMessageArray(array, {}) || array.value; }
Logging a simple message
A common usage is logging a message string to the console:
function LOG(msg) { var consoleService = Components.classes["@mozilla.org/consoleservice;1"] .getService(Components.interfaces.nsIConsoleService); consoleService.logStringMessage(msg); }
Alternative logging methods include Components.utils.reportError and dump().
Logging a message with additional information
To include other information an nsIConsoleMessage
object must be used. In this example nsIScriptError
, which implements nsIConsoleMessage
, is used to include information about the source file and line number of the error.
function myLogToConsole(aMessage, aSourceName, aSourceLine, aLineNumber, aColumnNumber, aFlags, aCategory) { var consoleService = Components.classes["@mozilla.org/consoleservice;1"] .getService(Components.interfaces.nsIConsoleService); var scriptError = Components.classes["@mozilla.org/scripterror;1"] .createInstance(Components.interfaces.nsIScriptError); scriptError.init(aMessage, aSourceName, aSourceLine, aLineNumber, aColumnNumber, aFlags, aCategory); consoleService.logMessage(scriptError); }
aMessage
— the string to be logged. You must provide this.aSourceName
— the URL for a file associated with an error. This will be a hyperlink in the Error Console, so you'd better use real URL. You may passnull
if it's not applicable.aSourceLine
— the line #aLineNumber
fromaSourceName
file. You are responsible for providing this line. You may passnull
if you are lazy; this will prevent the source line showing in the Error Console.aLineNumber
andaColumnNumber
— specify the exact location of an error.aColumnNumber
is used to draw the arrow pointing to the problem character.aFlags
— one of flags declared innsIScriptError
. At the time of writing, possible values are:nsIScriptError.errorFlag = 0
nsIScriptError.warningFlag = 1
nsIScriptError.exceptionFlag = 2
andnsIScriptError.strictFlag = 4
.
aCategory
— a string indicating what kind of code caused the error message. There are quite a few category strings and they do not currently seem to be listed in a single place. Hopefully, they will all eventually be listed innsIScriptError.idl
.
See also
- Error Console (deprecated)
- Web Console
- Browser Console
nsIConsoleMessage