src/support.js

   1 (function( jQuery ) {
   2
   3 (function() {
   4
   5         jQuery.support = {};
   6
   7         var root = document.documentElement,
   8                 script = document.createElement("script"),
   9                 div = document.createElement("div"),
  10                 id = "script" + jQuery.now();
  11
  12         div.style.display = "none";
  13         div.innerHTML = "   <link/><table></table><a href='/a' style='color:red;float:left;opacity:.55;'>a</a><input type='checkbox'/>";
  14
  15         var all = div.getElementsByTagName("*"),
  16                 a = div.getElementsByTagName("a")[0];
  17
  18         // Can't get basic test support
  19         if ( !all || !all.length || !a ) {
  20                 return;
  21         }
  22
  23         jQuery.support = {
  24                 // IE strips leading whitespace when .innerHTML is used
  25                 leadingWhitespace: div.firstChild.nodeType === 3,
  26
  27                 // Make sure that tbody elements aren't automatically inserted
  28                 // IE will insert them into empty tables
  29                 tbody: !div.getElementsByTagName("tbody").length,
  30
  31                 // Make sure that link elements get serialized correctly by innerHTML
  32                 // This requires a wrapper element in IE
  33                 htmlSerialize: !!div.getElementsByTagName("link").length,
  34
  35                 // Get the style information from getAttribute
  36                 // (IE uses .cssText insted)
  37                 style: /red/.test( a.getAttribute("style") ),
  38
  39                 // Make sure that URLs aren't manipulated
  40                 // (IE normalizes it by default)
  41                 hrefNormalized: a.getAttribute("href") === "/a",
  42
  43                 // Make sure that element opacity exists
  44                 // (IE uses filter instead)
  45                 // Use a regex to work around a WebKit issue. See #5145
  46                 opacity: /^0.55$/.test( a.style.opacity ),
  47
  48                 // Verify style float existence
  49                 // (IE uses styleFloat instead of cssFloat)
  50                 cssFloat: !!a.style.cssFloat,
  51
  52                 // Make sure that if no value is specified for a checkbox
  53                 // that it defaults to "on".
  54                 // (WebKit defaults to "" instead)
  55                 checkOn: div.getElementsByTagName("input")[0].value === "on",
  56
  57                 // Make sure that a selected-by-default option has a working selected property.
  58                 // (WebKit defaults to false instead of true, IE too, if it's in an optgroup)
  59                 optSelected: document.createElement("select").appendChild( document.createElement("option") ).selected,
  60
  61                 // Will be defined later
  62                 checkClone: false,
  63                 scriptEval: false,
  64                 noCloneEvent: true,
  65                 boxModel: null
  66         };
  67
  68         script.type = "text/javascript";
  69         try {
  70                 script.appendChild( document.createTextNode( "window." + id + "=1;" ) );
  71         } catch(e) {}
  72
  73         root.insertBefore( script, root.firstChild );
  74
  75         // Make sure that the execution of code works by injecting a script
  76         // tag with appendChild/createTextNode
  77         // (IE doesn't support this, fails, and uses .text instead)
  78         if ( window[ id ] ) {
  79                 jQuery.support.scriptEval = true;
  80                 delete window[ id ];
  81         }
  82
  83         root.removeChild( script );
  84
  85         if ( div.attachEvent && div.fireEvent ) {
  86                 div.attachEvent("onclick", function click() {
  87                         // Cloning a node shouldn't copy over any
  88                         // bound event handlers (IE does this)
  89                         jQuery.support.noCloneEvent = false;
  90                         div.detachEvent("onclick", click);
  91                 });
  92                 div.cloneNode(true).fireEvent("onclick");
  93         }
  94
  95         div = document.createElement("div");
  96         div.innerHTML = "<input type='radio' name='radiotest' checked='checked'/>";
  97
  98         var fragment = document.createDocumentFragment();
  99         fragment.appendChild( div.firstChild );
 100
 101         // WebKit doesn't clone checked state correctly in fragments
 102         jQuery.support.checkClone = fragment.cloneNode(true).cloneNode(true).lastChild.checked;
 103
 104         // Figure out if the W3C box model works as expected
 105         // document.body must exist before we can do this
 106         jQuery(function() {
 107                 var div = document.createElement("div");
 108                 div.style.width = div.style.paddingLeft = "1px";
 109
 110                 document.body.appendChild( div );
 111                 jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
 112                 document.body.removeChild( div ).style.display = 'none';
 113                 div = null;
 114         });
 115
 116         // Technique from Juriy Zaytsev
 117         // http://thinkweb2.com/projects/prototype/detecting-event-support-without-browser-sniffing/
 118         var eventSupported = function( eventName ) {
 119                 var el = document.createElement("div");
 120                 eventName = "on" + eventName;
 121
 122                 var isSupported = (eventName in el);
 123                 if ( !isSupported ) {
 124                         el.setAttribute(eventName, "return;");
 125                         isSupported = typeof el[eventName] === "function";
 126                 }
 127                 el = null;
 128
 129                 return isSupported;
 130         };
 131
 132         jQuery.support.submitBubbles = eventSupported("submit");
 133         jQuery.support.changeBubbles = eventSupported("change");
 134
 135         // release memory in IE
 136         root = script = div = all = a = null;
 137 })( jQuery );
 138
 139 jQuery.props = {
 140         "for": "htmlFor",
 141         "class": "className",
 142         readonly: "readOnly",
 143         maxlength: "maxLength",
 144         cellspacing: "cellSpacing",
 145         rowspan: "rowSpan",
 146         colspan: "colSpan",
 147         tabindex: "tabIndex",
 148         usemap: "useMap",
 149         frameborder: "frameBorder"
 150 };
 151
 152 })( jQuery );