gecko-dev/toolkit/identity/LogUtils.jsm
Matthew Noorenberghe da71fbd278 Bug 770418 - Improve identity logging output. r=dolske,jparsons
--HG--
extra : rebase_source : 4bfe055e1b783ffa80ad9b8515168a68e02f6a90
2012-07-10 23:54:27 -07:00

104 lines
2.9 KiB
JavaScript

/* -*- Mode: js2; js2-basic-offset: 2; indent-tabs-mode: nil; -*- */
/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const EXPORTED_SYMBOLS = ["Logger"];
const PREF_DEBUG = "toolkit.identity.debug";
const Cu = Components.utils;
const Ci = Components.interfaces;
const Cc = Components.classes;
const Cr = Components.results;
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
function IdentityLogger() {
Services.prefs.addObserver(PREF_DEBUG, this, false);
this._debug = Services.prefs.getBoolPref(PREF_DEBUG);
return this;
}
IdentityLogger.prototype = {
QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports, Ci.nsIObserver]),
observe: function observe(aSubject, aTopic, aData) {
switch(aTopic) {
case "nsPref:changed":
this._debug = Services.prefs.getBoolPref(PREF_DEBUG);
break;
case "quit-application-granted":
Services.prefs.removeObserver(PREF_DEBUG, this);
break;
default:
this.log("Logger observer", "Unknown topic:", aTopic);
break;
}
},
_generateLogMessage: function _generateLogMessage(aPrefix, args) {
// create a string representation of a list of arbitrary things
let strings = [];
// XXX bug 770418 - args look like flattened array, not list of strings
args.forEach(function(arg) {
if (typeof arg === 'string') {
strings.push(arg);
} else if (typeof arg === 'undefined') {
strings.push('undefined');
} else if (arg === null) {
strings.push('null');
} else {
try {
strings.push(JSON.stringify(arg, null, 2));
} catch(err) {
strings.push("<<something>>");
}
}
});
return 'Identity ' + aPrefix + ': ' + strings.join(' ');
},
/**
* log() - utility function to print a list of arbitrary things
*
* Enable with about:config pref toolkit.identity.debug
*/
log: function log(aPrefix, ...args) {
if (!this._debug) {
return;
}
let output = this._generateLogMessage(aPrefix, args);
dump(output + "\n");
// Additionally, make the output visible in the Error Console
Services.console.logStringMessage(output);
},
/**
* reportError() - report an error through component utils as well as
* our log function
*/
reportError: function reportError(aPrefix, ...aArgs) {
let prefix = aPrefix + ' ERROR';
// Report the error in the browser
let output = this._generateLogMessage(aPrefix, aArgs);
Cu.reportError(output);
dump("ERROR: " + output + "\n");
for (let frame = Components.stack.caller; frame; frame = frame.caller) {
dump(frame + "\n");
}
}
};
let Logger = new IdentityLogger();