☰

Validate Library Card

Performs error detection and correction.

  1. // ==UserScript==
  2. // @name           Validate Library Card
  3. // @namespace      http://mailerdaemon.home.comcast.com/
  4. // @include        https://*.libraryreserve.com/*/SignIn*.htm*
  5. // @include        https://*.libraryreserve.com/*/LogIn*.htm*
  6. // @version        1.0
  7. // @description Performs error detection and correction.
  8. // ==/UserScript==
  9.  
  10. const extrasize = 3;
  11.  
  12. function luhn(str){
  13. 	if(typeof(str) !== "string")
  14. 		str = Array.join(str, "");
  15. 	if((str = str.replace(/\D/g, "")).length) {
  16. 		var t = [0,2,4,6,8,1,3,5,7,9]
  17. 		var [valid, concat] = Array.reduce(str, function([b, a], c){ let j = Number(c); return [a + j, b + t[j]];}, [0, 0]);
  18. 		return [str, !(valid % 10), str.concat(9 - (concat + 9) % 10)];
  19. 	}
  20. 	return [str, undefined, "0"];
  21. }
  22.  
  23. $Z("//input[(@id='card' or @name='LibraryCardNumber') and @type='text']", function(input){
  24. 		let checksum = document.createElement("span");
  25. 		insertAfter(checksum, input)
  26. 		let update = function (e){
  27. 				let value = input.value.replace(/[\s\-_]/g,'');
  28. 				let len = value.length;
  29. 				let num = Number(value);
  30. 				let check;
  31. 				if(len && !isNaN(num))
  32. 				{
  33. 					if(len < 13){
  34. 						input.style.backgroundColor = "";
  35. 						checksum.innerHTML = check = "";
  36. 					}
  37. 					else if(len == 13){
  38. 						checksum.innerHTML = check = luhn(value)[2].slice(-1);
  39. 						input.style.backgroundColor = "#AFA";
  40. 					}
  41. 					else if(len == 14){
  42. 						var [str, success] = luhn(value);
  43. 						checksum.innerHTML = ""
  44. 						check = str.slice(-1);
  45. 						if(success)
  46. 							input.style.backgroundColor = "#5F5";
  47. 						else
  48. 							input.style.backgroundColor = "#FAA";
  49. 					}
  50. 					else
  51. 						input.style.backgroundColor = "#F00";
  52. 					//log(value, len, check)
  53. 				}
  54. 				//else log(value, "wtf?")
  55. 				if(input.value.length + extrasize > input.size)
  56. 					input.size = input.value.length + extrasize;
  57. 			}
  58. 		addEvent(input, "keyup", update);
  59. 		addEvent(input, "change", update);
  60. 		addEvent(checksum, "click", function(){input.value += checksum.innerHTML; update();});
  61. 	});
  62.  
  63. function $Z(_xpath, func, node){
  64.     var doc = (node && (typeof(node.ownerDocument) === "object"))?(node.ownerDocument || node):(node = document);
  65.     var res = doc.evaluate(_xpath, node, null,	XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
  66.     var args = Array.prototype.slice.call(arguments, 3);
  67.     var i = 0;
  68.     for (; i < res.snapshotLength; ++i)
  69.         func.apply(func, [res.snapshotItem(i), i].concat(args));
  70.     return i;
  71. }
  72.  
  73.  
  74. function insertAfter(insert, after){return after.parentNode.insertBefore(insert, after.nextSibling);}
  75. function insertBefore(insert, before){return before.parentNode.insertBefore(insert, before);}
  76.  
  77. function addEvent( obj, type, fn, capture ) {
  78.  	if ( obj.attachEvent ) {
  79.  		obj["e"+type+fn] = fn;
  80.  		obj[type+fn] = function() { obj["e"+type+fn]( window.event ); }
  81.  		obj.attachEvent( "on"+type, obj[type+fn] );
  82.  	} else
  83.  		obj.addEventListener( type, fn, capture?capture:false );
  84. }
  85. function removeEvent( obj, type, fn, capture ) {
  86.  	if ( obj.detachEvent ) {
  87.  		obj.detachEvent( "on"+type, obj[type+fn] );
  88.  		obj[type+fn] = obj["e"+type+fn] = null;
  89.  	} else
  90.  		obj.removeEventListener( type, fn, capture?capture:false );
  91. }
  92. function log(){
  93. 	var arg;
  94. 	switch(arguments.length)
  95. 	{
  96. 		case 1:
  97. 			arg = arguments[0];
  98. 			break;
  99. 		case 0:
  100. 			arg = null;
  101. 			break;
  102. 		default:
  103. 			arg = arguments;
  104. 			break;
  105. 	}
  106. 	
  107. 	var f = arg//JSON.stringify(arg);
  108. 	if(typeof(unsafeWindow.console) != "undefined" && typeof(unsafeWindow.console.log) != "undefined")
  109. 		unsafeWindow.console.log(f);
  110. 	else
  111. 		GM_log(f);
  112. 	return arg;
  113. }