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                 noCloneEvent: true,
  65                 boxModel: null,
  66                 inlineBlockNeedsLayout: false,
  67                 shrinkWrapBlocks: false,
  68                 reliableHiddenOffsets: true
  69         };
  70
  71         // Make sure that the options inside disabled selects aren't marked as disabled
  72         // (WebKit marks them as diabled)
  73         select.disabled = true;
  74         jQuery.support.optDisabled = !opt.disabled;
  75
  76         var _scriptEval = null;
  77         jQuery.support.scriptEval = function() {
  78                 if ( _scriptEval === null ) {
  79                         var root = document.documentElement,
  80                                 script = document.createElement("script"),
  81                                 id = "script" + jQuery.now();
  82
  83                         try {
  84                                 script.appendChild( document.createTextNode( "window." + id + "=1;" ) );
  85                         } catch(e) {}
  86
  87                         root.insertBefore( script, root.firstChild );
  88
  89                         // Make sure that the execution of code works by injecting a script
  90                         // tag with appendChild/createTextNode
  91                         // (IE doesn't support this, fails, and uses .text instead)
  92                         if ( window[ id ] ) {
  93                                 _scriptEval = true;
  94                                 delete window[ id ];
  95                         } else {
  96                                 _scriptEval = false;
  97                         }
  98
  99                         root.removeChild( script );
 100                         // release memory in IE
 101                         root = script = id  = null;
 102                 }
 103
 104                 return _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.addEventListener && 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                         body = document.getElementsByTagName("body")[0];
 140
 141                 // Frameset documents with no body should not run this code
 142                 if ( !body ) {
 143                         return;
 144                 }
 145
 146                 div.style.width = div.style.paddingLeft = "1px";
 147                 body.appendChild( div );
 148                 jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
 149
 150                 if ( "zoom" in div.style ) {
 151                         // Check if natively block-level elements act like inline-block
 152                         // elements when setting their display to 'inline' and giving
 153                         // them layout
 154                         // (IE < 8 does this)
 155                         div.style.display = "inline";
 156                         div.style.zoom = 1;
 157                         jQuery.support.inlineBlockNeedsLayout = div.offsetWidth === 2;
 158
 159                         // Check if elements with layout shrink-wrap their children
 160                         // (IE 6 does this)
 161                         div.style.display = "";
 162                         div.innerHTML = "<div style='width:4px;'></div>";
 163                         jQuery.support.shrinkWrapBlocks = div.offsetWidth !== 2;
 164                 }
 165
 166                 div.innerHTML = "<table><tr><td style='padding:0;border:0;display:none'></td><td>t</td></tr></table>";
 167                 var tds = div.getElementsByTagName("td");
 168
 169                 // Check if table cells still have offsetWidth/Height when they are set
 170                 // to display:none and there are still other visible table cells in a
 171                 // table row; if so, offsetWidth/Height are not reliable for use when
 172                 // determining if an element has been hidden directly using
 173                 // display:none (it is still safe to use offsets if a parent element is
 174                 // hidden; don safety goggles and see bug #4512 for more information).
 175                 // (only IE 8 fails this test)
 176                 jQuery.support.reliableHiddenOffsets = tds[0].offsetHeight === 0;
 177
 178                 tds[0].style.display = "";
 179                 tds[1].style.display = "none";
 180
 181                 // Check if empty table cells still have offsetWidth/Height
 182                 // (IE < 8 fail this test)
 183                 jQuery.support.reliableHiddenOffsets = jQuery.support.reliableHiddenOffsets && tds[0].offsetHeight === 0;
 184                 div.innerHTML = "";
 185
 186                 body.removeChild( div ).style.display = "none";
 187                 div = tds = null;
 188         });
 189
 190         // Technique from Juriy Zaytsev
 191         // http://thinkweb2.com/projects/prototype/detecting-event-support-without-browser-sniffing/
 192         var eventSupported = function( eventName ) {
 193                 var el = document.createElement("div");
 194                 eventName = "on" + eventName;
 195
 196                 // We only care about the case where non-standard event systems
 197                 // are used, namely in IE. Short-circuiting here helps us to
 198                 // avoid an eval call (in setAttribute) which can cause CSP
 199                 // to go haywire. See: https://developer.mozilla.org/en/Security/CSP
 200                 if ( !el.attachEvent ) {
 201                         return true;
 202                 }
 203
 204                 var isSupported = (eventName in el);
 205                 if ( !isSupported ) {
 206                         el.setAttribute(eventName, "return;");
 207                         isSupported = typeof el[eventName] === "function";
 208                 }
 209                 el = null;
 210
 211                 return isSupported;
 212         };
 213
 214         jQuery.support.submitBubbles = eventSupported("submit");
 215         jQuery.support.changeBubbles = eventSupported("change");
 216
 217         // release memory in IE
 218         div = all = a = null;
 219 })();
 220 })( jQuery );