default 0 value for undefined

jquery-pxem.js

@@ -0,0 +1,37 @@
+// https://github.com/0student/jQuery-Pixel-Em-Converter
+/*--------------------------------------------------------------------
+ * jQuery pixel/em conversion plugins: toEm() and toPx()
+ * by Scott Jehl ([email protected]), http://www.filamentgroup.com
+ * Copyright (c) Filament Group
+ * Dual licensed under the MIT (filamentgroup.com/examples/mit-license.txt) or GPL (filamentgroup.com/examples/gpl-license.txt) licenses.
+ * Article: http://www.filamentgroup.com/lab/update_jquery_plugin_for_retaining_scalable_interfaces_with_pixel_to_em_con/
+ * Options:
+ scope: string or jQuery selector for font-size scoping
+ * Usage Example: $(myPixelValue).toEm(); or $(myEmValue).toPx();
+ --------------------------------------------------------------------*/
+
+$.fn.toEm = function(settings){
+	settings = jQuery.extend({
+		scope: 'body'
+	}, settings);
+	// default 0 is required because $(0) holds jQuery init() function instead of 0 value yeldings this[0] = undefined
+	var that = parseInt(this[0] ||0, 10),
+			scopeTest = jQuery('<div style="display: none; font-size: 1em; margin: 0; padding:0; height: auto; line-height: 1; border:0;">&nbsp;</div>').appendTo(settings.scope),
+			scopeVal = scopeTest.height();
+	scopeTest.remove();
+	return (that / scopeVal).toFixed(8);
+};
+
+
+
+$.fn.toPx = function(settings){
+	settings = jQuery.extend({
+		scope: 'body'
+	}, settings);
+	// default 0 is required because $(0) holds jQuery init() function instead of 0 value yeldings this[0] = undefined
+	var that = parseFloat(this[0] || 0),
+			scopeTest = jQuery('<div style="display: none; font-size: 1em; margin: 0; padding:0; height: auto; line-height: 1; border:0;">&nbsp;</div>').appendTo(settings.scope),
+			scopeVal = scopeTest.height();
+	scopeTest.remove();
+	return Math.round(that * scopeVal);
+};