add OpenLayers.Console namespace and a number of methods that allow for logging of error messages - when firebug.js is included in a page, the application runs in "debug" mode - the Firebug extension or Firebug Lite handles OpenLayers.Console calls depending on availability

git-svn-id: http://svn.openlayers.org/trunk/openlayers@3320 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Console.js

@@ -0,0 +1,39 @@
+/* Copyright (c) 2006 MetaCarta, Inc., published under a modified BSD license.
+ * See http://svn.openlayers.org/trunk/openlayers/repository-license.txt 
+ * for the full text of the license. */
+
+/**
+ * The OpenLayers.Console namespace is used for debugging and error logging.
+ * If the Firebug Lite (../Firebug/firebug.js) is included before this script,
+ * calls to OpenLayers.Console methods will get redirected to window.console.
+ * This makes use of the Firebug extension where available and allows for
+ * cross-browser debugging Firebug style.
+ */
+OpenLayers.Console = {};
+(function() {
+    /**
+     * Create empty functions for all console methods.  The real value of these
+     * properties will be set if Firebug Lite (../Firebug/firebug.js script) is
+     * included.  We explicitly require the Firebug Lite script to trigger
+     * functionality of the OpenLayers.Console methods.
+     */
+    var methods = ['log', 'debug', 'info', 'warn', 'error', 'assert',
+                   'dir', 'dirxml', 'trace', 'group', 'groupEnd', 'time',
+                   'timeEnd', 'profile', 'profileEnd', 'count'];
+    for(var i=0; i<methods.length; ++i) {
+        OpenLayers.Console[methods[i]] = function() {};
+    }
+    /**
+     * If Firebug Lite is included (before this script), re-route all
+     * OpenLayers.Console calls to the console object.
+     */
+    if(window.console) {
+        var scripts = document.getElementsByTagName("script");
+        for(var i=0; i<scripts.length; ++i) {
+            if(scripts[i].src.indexOf("firebug.js") != -1) {
+                OpenLayers.Util.extend(OpenLayers.Console, console);
+                break;
+            }
+        }
+    }
+})();