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                 reliableMarginRight: true
  72         };
  73
  74         input.checked = true;
  75         jQuery.support.noCloneChecked = input.cloneNode( true ).checked;
  76
  77         // Make sure that the options inside disabled selects aren't marked as disabled
  78         // (WebKit marks them as diabled)
  79         select.disabled = true;
  80         jQuery.support.optDisabled = !opt.disabled;
  81
  82         var _scriptEval = null;
  83         jQuery.support.scriptEval = function() {
  84                 if ( _scriptEval === null ) {
  85                         var root = document.documentElement,
  86                                 script = document.createElement("script"),
  87                                 id = "script" + jQuery.now();
  88
  89                         try {
  90                                 script.appendChild( document.createTextNode( "window." + id + "=1;" ) );
  91                         } catch(e) {}
  92
  93                         root.insertBefore( script, root.firstChild );
  94
  95                         // Make sure that the execution of code works by injecting a script
  96                         // tag with appendChild/createTextNode
  97                         // (IE doesn't support this, fails, and uses .text instead)
  98                         if ( window[ id ] ) {
  99                                 _scriptEval = true;
 100                                 delete window[ id ];
 101                         } else {
 102                                 _scriptEval = false;
 103                         }
 104
 105                         root.removeChild( script );
 106                         // release memory in IE
 107                         root = script = id  = null;
 108                 }
 109
 110                 return _scriptEval;
 111         };
 112
 113         // Test to see if it's possible to delete an expando from an element
 114         // Fails in Internet Explorer
 115         try {
 116                 delete div.test;
 117
 118         } catch(e) {
 119                 jQuery.support.deleteExpando = false;
 120         }
 121
 122         if ( !div.addEventListener && div.attachEvent && div.fireEvent ) {
 123                 div.attachEvent("onclick", function click() {
 124                         // Cloning a node shouldn't copy over any
 125                         // bound event handlers (IE does this)
 126                         jQuery.support.noCloneEvent = false;
 127                         div.detachEvent("onclick", click);
 128                 });
 129                 div.cloneNode(true).fireEvent("onclick");
 130         }
 131
 132         div = document.createElement("div");
 133         div.innerHTML = "<input type='radio' name='radiotest' checked='checked'/>";
 134
 135         var fragment = document.createDocumentFragment();
 136         fragment.appendChild( div.firstChild );
 137
 138         // WebKit doesn't clone checked state correctly in fragments
 139         jQuery.support.checkClone = fragment.cloneNode(true).cloneNode(true).lastChild.checked;
 140
 141         // Figure out if the W3C box model works as expected
 142         // document.body must exist before we can do this
 143         jQuery(function() {
 144                 var div = document.createElement("div"),
 145                         body = document.getElementsByTagName("body")[0];
 146
 147                 // Frameset documents with no body should not run this code
 148                 if ( !body ) {
 149                         return;
 150                 }
 151
 152                 div.style.width = div.style.paddingLeft = "1px";
 153                 body.appendChild( div );
 154                 jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
 155
 156                 if ( "zoom" in div.style ) {
 157                         // Check if natively block-level elements act like inline-block
 158                         // elements when setting their display to 'inline' and giving
 159                         // them layout
 160                         // (IE < 8 does this)
 161                         div.style.display = "inline";
 162                         div.style.zoom = 1;
 163                         jQuery.support.inlineBlockNeedsLayout = div.offsetWidth === 2;
 164
 165                         // Check if elements with layout shrink-wrap their children
 166                         // (IE 6 does this)
 167                         div.style.display = "";
 168                         div.innerHTML = "<div style='width:4px;'></div>";
 169                         jQuery.support.shrinkWrapBlocks = div.offsetWidth !== 2;
 170                 }
 171
 172                 div.innerHTML = "<table><tr><td style='padding:0;border:0;display:none'></td><td>t</td></tr></table>";
 173                 var tds = div.getElementsByTagName("td");
 174
 175                 // Check if table cells still have offsetWidth/Height when they are set
 176                 // to display:none and there are still other visible table cells in a
 177                 // table row; if so, offsetWidth/Height are not reliable for use when
 178                 // determining if an element has been hidden directly using
 179                 // display:none (it is still safe to use offsets if a parent element is
 180                 // hidden; don safety goggles and see bug #4512 for more information).
 181                 // (only IE 8 fails this test)
 182                 jQuery.support.reliableHiddenOffsets = tds[0].offsetHeight === 0;
 183
 184                 tds[0].style.display = "";
 185                 tds[1].style.display = "none";
 186
 187                 // Check if empty table cells still have offsetWidth/Height
 188                 // (IE < 8 fail this test)
 189                 jQuery.support.reliableHiddenOffsets = jQuery.support.reliableHiddenOffsets && tds[0].offsetHeight === 0;
 190                 div.innerHTML = "";
 191
 192                 // Check if div with explicit width and no margin-right incorrectly
 193                 // gets computed margin-right based on width of container. For more
 194                 // info see bug #3333
 195                 // Fails in WebKit before Feb 2011 nightlies
 196                 // WebKit Bug 13343 - getComputedStyle returns wrong value for margin-right
 197                 if ( document.defaultView && document.defaultView.getComputedStyle ) {
 198                         div.style.width = "1px";
 199                         div.style.marginRight = "0";
 200                         jQuery.support.reliableMarginRight = ( parseInt(document.defaultView.getComputedStyle(div).marginRight, 10) || 0 ) === 0;
 201                 }
 202
 203                 body.removeChild( div ).style.display = "none";
 204                 div = tds = null;
 205         });
 206
 207         // Technique from Juriy Zaytsev
 208         // http://thinkweb2.com/projects/prototype/detecting-event-support-without-browser-sniffing/
 209         var eventSupported = function( eventName ) {
 210                 var el = document.createElement("div");
 211                 eventName = "on" + eventName;
 212
 213                 // We only care about the case where non-standard event systems
 214                 // are used, namely in IE. Short-circuiting here helps us to
 215                 // avoid an eval call (in setAttribute) which can cause CSP
 216                 // to go haywire. See: https://developer.mozilla.org/en/Security/CSP
 217                 if ( !el.attachEvent ) {
 218                         return true;
 219                 }
 220
 221                 var isSupported = (eventName in el);
 222                 if ( !isSupported ) {
 223                         el.setAttribute(eventName, "return;");
 224                         isSupported = typeof el[eventName] === "function";
 225                 }
 226                 el = null;
 227
 228                 return isSupported;
 229         };
 230
 231         jQuery.support.submitBubbles = eventSupported("submit");
 232         jQuery.support.changeBubbles = eventSupported("change");
 233
 234         // release memory in IE
 235         div = all = a = null;
 236 })();
 237 })( jQuery );