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                 input = div.getElementsByTagName("input")[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: input.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: opt.selected,
  60
  61                 // Will be defined later
  62                 deleteExpando: true,
  63                 optDisabled: false,
  64                 checkClone: false,
  65                 noCloneEvent: true,
  66                 noCloneChecked: true,
  67                 boxModel: null,
  68                 inlineBlockNeedsLayout: false,
  69                 shrinkWrapBlocks: false,
  70                 reliableHiddenOffsets: true
  71         };
  72
  73         input.checked = true;
  74         jQuery.support.noCloneChecked = input.cloneNode( true ).checked;
  75
  76         // Make sure that the options inside disabled selects aren't marked as disabled
  77         // (WebKit marks them as diabled)
  78         select.disabled = true;
  79         jQuery.support.optDisabled = !opt.disabled;
  80
  81         var _scriptEval = null;
  82         jQuery.support.scriptEval = function() {
  83                 if ( _scriptEval === null ) {
  84                         var root = document.documentElement,
  85                                 script = document.createElement("script"),
  86                                 id = "script" + jQuery.now();
  87
  88                         try {
  89                                 script.appendChild( document.createTextNode( "window." + id + "=1;" ) );
  90                         } catch(e) {}
  91
  92                         root.insertBefore( script, root.firstChild );
  93
  94                         // Make sure that the execution of code works by injecting a script
  95                         // tag with appendChild/createTextNode
  96                         // (IE doesn't support this, fails, and uses .text instead)
  97                         if ( window[ id ] ) {
  98                                 _scriptEval = true;
  99                                 delete window[ id ];
 100                         } else {
 101                                 _scriptEval = false;
 102                         }
 103
 104                         root.removeChild( script );
 105                         // release memory in IE
 106                         root = script = id  = null;
 107                 }
 108
 109                 return _scriptEval;
 110         };
 111
 112         // Test to see if it's possible to delete an expando from an element
 113         // Fails in Internet Explorer
 114         try {
 115                 delete div.test;
 116
 117         } catch(e) {
 118                 jQuery.support.deleteExpando = false;
 119         }
 120
 121         if ( !div.addEventListener && div.attachEvent && div.fireEvent ) {
 122                 div.attachEvent("onclick", function click() {
 123                         // Cloning a node shouldn't copy over any
 124                         // bound event handlers (IE does this)
 125                         jQuery.support.noCloneEvent = false;
 126                         div.detachEvent("onclick", click);
 127                 });
 128                 div.cloneNode(true).fireEvent("onclick");
 129         }
 130
 131         div = document.createElement("div");
 132         div.innerHTML = "<input type='radio' name='radiotest' checked='checked'/>";
 133
 134         var fragment = document.createDocumentFragment();
 135         fragment.appendChild( div.firstChild );
 136
 137         // WebKit doesn't clone checked state correctly in fragments
 138         jQuery.support.checkClone = fragment.cloneNode(true).cloneNode(true).lastChild.checked;
 139
 140         // Figure out if the W3C box model works as expected
 141         // document.body must exist before we can do this
 142         jQuery(function() {
 143                 var div = document.createElement("div"),
 144                         body = document.getElementsByTagName("body")[0];
 145
 146                 // Frameset documents with no body should not run this code
 147                 if ( !body ) {
 148                         return;
 149                 }
 150
 151                 div.style.width = div.style.paddingLeft = "1px";
 152                 body.appendChild( div );
 153                 jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
 154
 155                 if ( "zoom" in div.style ) {
 156                         // Check if natively block-level elements act like inline-block
 157                         // elements when setting their display to 'inline' and giving
 158                         // them layout
 159                         // (IE < 8 does this)
 160                         div.style.display = "inline";
 161                         div.style.zoom = 1;
 162                         jQuery.support.inlineBlockNeedsLayout = div.offsetWidth === 2;
 163
 164                         // Check if elements with layout shrink-wrap their children
 165                         // (IE 6 does this)
 166                         div.style.display = "";
 167                         div.innerHTML = "<div style='width:4px;'></div>";
 168                         jQuery.support.shrinkWrapBlocks = div.offsetWidth !== 2;
 169                 }
 170
 171                 div.innerHTML = "<table><tr><td style='padding:0;border:0;display:none'></td><td>t</td></tr></table>";
 172                 var tds = div.getElementsByTagName("td");
 173
 174                 // Check if table cells still have offsetWidth/Height when they are set
 175                 // to display:none and there are still other visible table cells in a
 176                 // table row; if so, offsetWidth/Height are not reliable for use when
 177                 // determining if an element has been hidden directly using
 178                 // display:none (it is still safe to use offsets if a parent element is
 179                 // hidden; don safety goggles and see bug #4512 for more information).
 180                 // (only IE 8 fails this test)
 181                 jQuery.support.reliableHiddenOffsets = tds[0].offsetHeight === 0;
 182
 183                 tds[0].style.display = "";
 184                 tds[1].style.display = "none";
 185
 186                 // Check if empty table cells still have offsetWidth/Height
 187                 // (IE < 8 fail this test)
 188                 jQuery.support.reliableHiddenOffsets = jQuery.support.reliableHiddenOffsets && tds[0].offsetHeight === 0;
 189                 div.innerHTML = "";
 190
 191                 body.removeChild( div ).style.display = "none";
 192                 div = tds = null;
 193         });
 194
 195         // Technique from Juriy Zaytsev
 196         // http://thinkweb2.com/projects/prototype/detecting-event-support-without-browser-sniffing/
 197         var eventSupported = function( eventName ) {
 198                 var el = document.createElement("div");
 199                 eventName = "on" + eventName;
 200
 201                 // We only care about the case where non-standard event systems
 202                 // are used, namely in IE. Short-circuiting here helps us to
 203                 // avoid an eval call (in setAttribute) which can cause CSP
 204                 // to go haywire. See: https://developer.mozilla.org/en/Security/CSP
 205                 if ( !el.attachEvent ) {
 206                         return true;
 207                 }
 208
 209                 var isSupported = (eventName in el);
 210                 if ( !isSupported ) {
 211                         el.setAttribute(eventName, "return;");
 212                         isSupported = typeof el[eventName] === "function";
 213                 }
 214                 el = null;
 215
 216                 return isSupported;
 217         };
 218
 219         jQuery.support.submitBubbles = eventSupported("submit");
 220         jQuery.support.changeBubbles = eventSupported("change");
 221
 222         // release memory in IE
 223         div = all = a = null;
 224 })();
 225 })( jQuery );