1 /* document.getElementsBySelector(selector)

     2    - returns an array of element objects from the current document

     3      matching the CSS selector. Selectors can contain element names, 

     4      class names and ids and can be nested. For example:

     5      

     6        elements = document.getElementsBySelect('div#main p a.external')

     7      

     8      Will return an array of all 'a' elements with 'external' in their 

     9      class attribute that are contained inside 'p' elements that are 

    10      contained inside the 'div' element which has id="main"

    11 

    12    New in version 0.4: Support for CSS2 and CSS3 attribute selectors:

    13    See http://www.w3.org/TR/css3-selectors/#attribute-selectors

    14 

    15    Version 0.4 - Simon Willison, March 25th 2003

    16    -- Works in Phoenix 0.5, Mozilla 1.3, Opera 7, Internet Explorer 6, Internet Explorer 5 on Windows

    17    -- Opera 7 fails 

    18 */

    19 

    20 function getAllChildren(e) {

    21   // Returns all children of element. Workaround required for IE5/Windows. Ugh.

    22   return e.all ? e.all : e.getElementsByTagName('*');

    23 }

    24 

    25 document.getElementsBySelector = function(selector) {

    26   // Attempt to fail gracefully in lesser browsers

    27   if (!document.getElementsByTagName) {

    28     return new Array();

    29   }

    30   // Split selector in to tokens

    31   var tokens = selector.split(' ');

    32   var currentContext = new Array(document);

    33   for (var i = 0; i < tokens.length; i++) {

    34     token = tokens[i].replace(/^\s+/,'').replace(/\s+$/,'');;

    35     if (token.indexOf('#') > -1) {

    36       // Token is an ID selector

    37       var bits = token.split('#');

    38       var tagName = bits[0];

    39       var id = bits[1];

    40       var element = document.getElementById(id);

    41       if (tagName && element.nodeName.toLowerCase() != tagName) {

    42         // tag with that ID not found, return false

    43         return new Array();

    44       }

    45       // Set currentContext to contain just this element

    46       currentContext = new Array(element);

    47       continue; // Skip to next token

    48     }

    49     if (token.indexOf('.') > -1) {

    50       // Token contains a class selector

    51       var bits = token.split('.');

    52       var tagName = bits[0];

    53       var className = bits[1];

    54       if (!tagName) {

    55         tagName = '*';

    56       }

    57       // Get elements matching tag, filter them for class selector

    58       var found = new Array;

    59       var foundCount = 0;

    60       for (var h = 0; h < currentContext.length; h++) {

    61         var elements;

    62         if (tagName == '*') {

    63             elements = getAllChildren(currentContext[h]);

    64         } else {

    65             try {

    66                 elements = currentContext[h].getElementsByTagName(tagName);

    67             }

    68             catch(e) {

    69                 elements = [];

    70             }

    71         }

    72         for (var j = 0; j < elements.length; j++) {

    73           found[foundCount++] = elements[j];

    74         }

    75       }

    76       currentContext = new Array;

    77       var currentContextIndex = 0;

    78       for (var k = 0; k < found.length; k++) {

    79         if (found[k].className && found[k].className.match(new RegExp('\\b'+className+'\\b'))) {

    80           currentContext[currentContextIndex++] = found[k];

    81         }

    82       }

    83       continue; // Skip to next token

    84     }

    85     // Code to deal with attribute selectors

    86     if (token.match(/^(\w*)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/)) {

    87       var tagName = RegExp.$1;

    88       var attrName = RegExp.$2;

    89       var attrOperator = RegExp.$3;

    90       var attrValue = RegExp.$4;

    91       if (!tagName) {

    92         tagName = '*';

    93       }

    94       // Grab all of the tagName elements within current context

    95       var found = new Array;

    96       var foundCount = 0;

    97       for (var h = 0; h < currentContext.length; h++) {

    98         var elements;

    99         if (tagName == '*') {

   100             elements = getAllChildren(currentContext[h]);

   101         } else {

   102             elements = currentContext[h].getElementsByTagName(tagName);

   103         }

   104         for (var j = 0; j < elements.length; j++) {

   105           found[foundCount++] = elements[j];

   106         }

   107       }

   108       currentContext = new Array;

   109       var currentContextIndex = 0;

   110       var checkFunction; // This function will be used to filter the elements

   111       switch (attrOperator) {

   112         case '=': // Equality

   113           checkFunction = function(e) { return (e.getAttribute(attrName) == attrValue); };

   114           break;

   115         case '~': // Match one of space seperated words 

   116           checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('\\b'+attrValue+'\\b'))); };

   117           break;

   118         case '|': // Match start with value followed by optional hyphen

   119           checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('^'+attrValue+'-?'))); };

   120           break;

   121         case '^': // Match starts with value

   122           checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) == 0); };

   123           break;

   124         case '$': // Match ends with value - fails with "Warning" in Opera 7

   125           checkFunction = function(e) { return (e.getAttribute(attrName).lastIndexOf(attrValue) == e.getAttribute(attrName).length - attrValue.length); };

   126           break;

   127         case '*': // Match ends with value

   128           checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) > -1); };

   129           break;

   130         default :

   131           // Just test for existence of attribute

   132           checkFunction = function(e) { return e.getAttribute(attrName); };

   133       }

   134       currentContext = new Array;

   135       var currentContextIndex = 0;

   136       for (var k = 0; k < found.length; k++) {

   137         if (checkFunction(found[k])) {

   138           currentContext[currentContextIndex++] = found[k];

   139         }

   140       }

   141       // alert('Attribute Selector: '+tagName+' '+attrName+' '+attrOperator+' '+attrValue);

   142       continue; // Skip to next token

   143     }

   144     // If we get here, token is JUST an element (not a class or ID selector)

   145     tagName = token;

   146     var found = new Array;

   147     var foundCount = 0;

   148     for (var h = 0; h < currentContext.length; h++) {

   149       var elements = currentContext[h].getElementsByTagName(tagName);

   150       for (var j = 0; j < elements.length; j++) {

   151         found[foundCount++] = elements[j];

   152       }

   153     }

   154     currentContext = found;

   155   }

   156   return currentContext;

   157 }

   158 

   159 /* That revolting regular expression explained 

   160 /^(\w+)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/

   161   \---/  \---/\-------------/    \-------/

   162     |      |         |               |

   163     |      |         |           The value

   164     |      |    ~,|,^,$,* or =

   165     |   Attribute 

   166    Tag

   167 */