src/support.js

   1 (function( jQuery ) {
   2
   3 (function() {
   4
   5         jQuery.support = {};
   6
   7         var div = document.createElement("div");
   8
   9         div.style.display = "none";
  10         div.innerHTML = "   <link/><table></table><a href='/a' style='color:red;float:left;opacity:.55;'>a</a><input type='checkbox'/>";
  11
  12         var all = div.getElementsByTagName("*"),
  13                 a = div.getElementsByTagName("a")[0],
  14                 select = document.createElement("select"),
  15                 opt = select.appendChild( document.createElement("option") );
  16
  17         // Can't get basic test support
  18         if ( !all || !all.length || !a ) {
  19                 return;
  20         }
  21
  22         jQuery.support = {
  23                 // IE strips leading whitespace when .innerHTML is used
  24                 leadingWhitespace: div.firstChild.nodeType === 3,
  25
  26                 // Make sure that tbody elements aren't automatically inserted
  27                 // IE will insert them into empty tables
  28                 tbody: !div.getElementsByTagName("tbody").length,
  29
  30                 // Make sure that link elements get serialized correctly by innerHTML
  31                 // This requires a wrapper element in IE
  32                 htmlSerialize: !!div.getElementsByTagName("link").length,
  33
  34                 // Get the style information from getAttribute
  35                 // (IE uses .cssText insted)
  36                 style: /red/.test( a.getAttribute("style") ),
  37
  38                 // Make sure that URLs aren't manipulated
  39                 // (IE normalizes it by default)
  40                 hrefNormalized: a.getAttribute("href") === "/a",
  41
  42                 // Make sure that element opacity exists
  43                 // (IE uses filter instead)
  44                 // Use a regex to work around a WebKit issue. See #5145
  45                 opacity: /^0.55$/.test( a.style.opacity ),
  46
  47                 // Verify style float existence
  48                 // (IE uses styleFloat instead of cssFloat)
  49                 cssFloat: !!a.style.cssFloat,
  50
  51                 // Make sure that if no value is specified for a checkbox
  52                 // that it defaults to "on".
  53                 // (WebKit defaults to "" instead)
  54                 checkOn: div.getElementsByTagName("input")[0].value === "on",
  55
  56                 // Make sure that a selected-by-default option has a working selected property.
  57                 // (WebKit defaults to false instead of true, IE too, if it's in an optgroup)
  58                 optSelected: opt.selected,
  59
  60                 // Will be defined later
  61                 deleteExpando: true,
  62                 optDisabled: false,
  63                 checkClone: false,
  64                 _scriptEval: null,
  65                 noCloneEvent: true,
  66                 boxModel: null,
  67                 inlineBlockNeedsLayout: false,
  68                 shrinkWrapBlocks: false,
  69                 reliableHiddenOffsets: true
  70         };
  71
  72         // Make sure that the options inside disabled selects aren't marked as disabled
  73         // (WebKit marks them as diabled)
  74         select.disabled = true;
  75         jQuery.support.optDisabled = !opt.disabled;
  76
  77         jQuery.support.scriptEval = function() {
  78                 if ( jQuery.support._scriptEval === null) {
  79                         var root = document.documentElement,
  80                                 script = document.createElement("script"),
  81                                 id = "script" + jQuery.now();
  82
  83                         script.type = "text/javascript";
  84                         try {
  85                                 script.appendChild( document.createTextNode( "window." + id + "=1;" ) );
  86                         } catch(e) {}
  87
  88                         root.insertBefore( script, root.firstChild );
  89
  90                         // Make sure that the execution of code works by injecting a script
  91                         // tag with appendChild/createTextNode
  92                         // (IE doesn't support this, fails, and uses .text instead)
  93                         if ( window[ id ] ) {
  94                                 jQuery.support._scriptEval = true;
  95                                 delete window[ id ];
  96                         } else {
  97                                 jQuery.support._scriptEval = false;
  98                         }
  99
 100                         root.removeChild( script );
 101                         // release memory in IE
 102                         root = script = id  = null;
 103                 }
 104                 return jQuery.support._scriptEval;
 105         };
 106
 107         // Test to see if it's possible to delete an expando from an element
 108         // Fails in Internet Explorer
 109         try {
 110                 delete div.test;
 111
 112         } catch(e) {
 113                 jQuery.support.deleteExpando = false;
 114         }
 115
 116         if ( div.attachEvent && div.fireEvent ) {
 117                 div.attachEvent("onclick", function click() {
 118                         // Cloning a node shouldn't copy over any
 119                         // bound event handlers (IE does this)
 120                         jQuery.support.noCloneEvent = false;
 121                         div.detachEvent("onclick", click);
 122                 });
 123                 div.cloneNode(true).fireEvent("onclick");
 124         }
 125
 126         div = document.createElement("div");
 127         div.innerHTML = "<input type='radio' name='radiotest' checked='checked'/>";
 128
 129         var fragment = document.createDocumentFragment();
 130         fragment.appendChild( div.firstChild );
 131
 132         // WebKit doesn't clone checked state correctly in fragments
 133         jQuery.support.checkClone = fragment.cloneNode(true).cloneNode(true).lastChild.checked;
 134
 135         // Figure out if the W3C box model works as expected
 136         // document.body must exist before we can do this
 137         jQuery(function() {
 138                 var div = document.createElement("div");
 139                 div.style.width = div.style.paddingLeft = "1px";
 140
 141                 document.body.appendChild( div );
 142                 jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
 143
 144                 if ( "zoom" in div.style ) {
 145                         // Check if natively block-level elements act like inline-block
 146                         // elements when setting their display to 'inline' and giving
 147                         // them layout
 148                         // (IE < 8 does this)
 149                         div.style.display = "inline";
 150                         div.style.zoom = 1;
 151                         jQuery.support.inlineBlockNeedsLayout = div.offsetWidth === 2;
 152
 153                         // Check if elements with layout shrink-wrap their children
 154                         // (IE 6 does this)
 155                         div.style.display = "";
 156                         div.innerHTML = "<div style='width:4px;'></div>";
 157                         jQuery.support.shrinkWrapBlocks = div.offsetWidth !== 2;
 158                 }
 159
 160                 div.innerHTML = "<table><tr><td style='padding:0;border:0;display:none'></td><td>t</td></tr></table>";
 161                 var tds = div.getElementsByTagName("td");
 162
 163                 // Check if table cells still have offsetWidth/Height when they are set
 164                 // to display:none and there are still other visible table cells in a
 165                 // table row; if so, offsetWidth/Height are not reliable for use when
 166                 // determining if an element has been hidden directly using
 167                 // display:none (it is still safe to use offsets if a parent element is
 168                 // hidden; don safety goggles and see bug #4512 for more information).
 169                 // (only IE 8 fails this test)
 170                 jQuery.support.reliableHiddenOffsets = tds[0].offsetHeight === 0;
 171
 172                 tds[0].style.display = "";
 173                 tds[1].style.display = "none";
 174
 175                 // Check if empty table cells still have offsetWidth/Height
 176                 // (IE < 8 fail this test)
 177                 jQuery.support.reliableHiddenOffsets = jQuery.support.reliableHiddenOffsets && tds[0].offsetHeight === 0;
 178                 div.innerHTML = "";
 179
 180                 document.body.removeChild( div ).style.display = "none";
 181                 div = tds = null;
 182         });
 183
 184         // Technique from Juriy Zaytsev
 185         // http://thinkweb2.com/projects/prototype/detecting-event-support-without-browser-sniffing/
 186         var eventSupported = function( eventName ) {
 187                 var el = document.createElement("div");
 188                 eventName = "on" + eventName;
 189
 190                 var isSupported = (eventName in el);
 191                 if ( !isSupported ) {
 192                         el.setAttribute(eventName, "return;");
 193                         isSupported = typeof el[eventName] === "function";
 194                 }
 195                 el = null;
 196
 197                 return isSupported;
 198         };
 199
 200         jQuery.support.submitBubbles = eventSupported("submit");
 201         jQuery.support.changeBubbles = eventSupported("change");
 202
 203         // release memory in IE
 204         div = all = a = null;
 205 })();
 206 })( jQuery );