Fix #6593. Don't let onchange trigger twice for elements in IE.

This is a major revamp of the approach we use for IE change events. Instead of trying to track and simulate, we lazy-attach real change events to inputs and have only one workaround for check/radio. Somewhat more resource intensive but closes several sticky bugs. The onchange is still triggered for check/radio on blur but no double-trigger on any element occurs.

diff --git a/src/event.js b/src/event.js
index da787ea85995b59030b43b923ada2cad940aef95..28716ad5ffc7e00d5f3c13c63653d97e28998494 100644 (file)
--- a/src/event.js
+++ b/src/event.js
@@ -336,7 +336,9 @@ jQuery.event = {
 
                // Clean up the event in case it is being reused
                event.result = undefined;
-               event.target = elem;
+               if ( !event.target ) {
+                       event.target = elem;
+               }
 
                // Clone any incoming data and prepend the event, creating the handler arg list
                data = data != null ? jQuery.makeArray( data ) : [];
@@ -754,111 +756,49 @@ if ( !jQuery.support.submitBubbles ) {
 
 }
 
-// change delegation, happens here so we have bind.
+// IE change delegation and checkbox/radio fix
 if ( !jQuery.support.changeBubbles ) {
 
-       var getVal = function( elem ) {
-               var type = jQuery.nodeName( elem, "input" ) ? elem.type : "",
-                       val = elem.value;
-
-               if ( type === "radio" || type === "checkbox" ) {
-                       val = elem.checked;
-
-               } else if ( type === "select-one" ) {
-                       val = elem.selectedIndex;
-
-               } else if ( type === "select-multiple" ) {
-                       val = elem.selectedIndex > -1 ?
-                               jQuery.map( elem.options, function( elem ) {
-                                       return elem.selected;
-                               }).join( "-" ) :
-                               "";
-               }
-
-               return val;
-       },
-
-       testChange = function testChange( e ) {
-               var elem = e.target,
-                       old, val;
-
-               if ( !rformElems.test( elem.nodeName ) || elem.readOnly ) {
-                       return;
-               }
-
-               old = jQuery._data( elem, "_change_data" );
-               val = getVal( elem );
-
-               // the current data will be also retrieved by beforeactivate
-               if ( e.type !== "focusout" || elem.type !== "radio" ) {
-                       jQuery._data( elem, "_change_data", val );
-               }
-
-               if ( val !== old && old != null ) {
-                       simulate( "change", elem,  e, true );
-               }
-       },
-
-       changeFilters = {
-               focusout: testChange,
-
-               beforedeactivate: testChange,
-
-               click: function( e ) {
-                       var elem = e.target,
-                               name = elem.nodeName.toLowerCase(),
-                               type = name === "input"? elem.type : "";
-
-                       if ( type === "radio" || type === "checkbox" || name === "select" ) {
-                                       testChange.call( this, e );
-                       }
-               },
-
-               // Change has to be called before submit
-               // Keydown will be called before keypress, which is used in submit-event delegation
-               keydown: function( e ) {
-                       var elem = e.target,
-                               name = elem.nodeName.toLowerCase(),
-                               type = name === "input"? elem.type : "";
-
-                       if ( (e.keyCode === 13 && name !== "textarea") ||
-                                       (e.keyCode === 32 && (type === "checkbox" || type === "radio")) ||
-                                       type === "select-multiple" ) {
-                                       testChange.call( this, e );
-                       }
-               },
-
-               // Beforeactivate happens also before the previous element is blurred
-               // here, you can't trigger a change event, but you can store data
-               beforeactivate: function( e ) {
-                       var elem = e.target;
-                       jQuery._data( elem, "_change_data", getVal( elem ) );
-               },
-
-               // Update the current value if we're not re-focusing (#8157)
-               focus: function( e ) {
-                       var elem = e.target;
-                       if ( elem != document.activeElement ) {
-                               jQuery._data( elem, "_change_data", getVal( elem ) );
-                       }
-               }
-       };
-
        jQuery.event.special.change = {
 
-               setup: function( data, namespaces ) {
-                       if ( this.type === "file" ) {
+               setup: function() {
+
+                       if ( rformElems.test( this.nodeName ) ) {
+                               // IE doesn't fire change on a checkbox/radio until blur; make it happen
+                               // immediately by triggering our own change event now.
+                               // Avoid double-firing change by eating it in special.change.handle.
+                               if ( this.type === "checkbox" || this.type === "radio" ) {
+                                       jQuery.event.add( this, "click._change", function( event ) {
+                                               simulate( "change", this, event, true );
+                                       });
+                               }
                                return false;
                        }
+                       // Delegated event; lazy-add a change handler on descendant inputs
+                       jQuery.event.add( this, "beforeactivate._change", function( e ) {
+                               var elem = e.target;
+
+                               if ( rformElems.test( elem.nodeName ) && !elem._change_attached ) {                                     
+                                       jQuery.event.add( elem, "change._change", function( event ) {
+                                               if ( this.parentNode && !event.isSimulated ) {
+                                                       simulate( "change", this.parentNode, event, true );
+                                               }
+                                       });
+                                       elem._change_attached = true;
+                               }
+                       });
+               },
+               
+               handle: function( event ) {
+                       var elem = event.target;
 
-                       for ( var type in changeFilters ) {
-                               jQuery.event.add( this, type + "._change", changeFilters[ type ] );
+                       // Swallow native change events from checkbox/radio, we already triggered them above
+                       if ( this !== elem || event.isSimulated || (elem.type !== "radio" && elem.type !== "checkbox") ) {
+                               return event.handleObj.handler.apply( this, arguments );
                        }
-
-                       return rformElems.test( this.nodeName );
                },
 
-               teardown: function( namespaces ) {
+               teardown: function() {
                        jQuery.event.remove( this, "._change" );
 
                        return rformElems.test( this.nodeName );
@@ -870,7 +810,11 @@ function simulate( type, elem, event, bubble ) {
        // Piggyback on a donor event to simulate a different one.
        // Fake originalEvent to avoid donor's stopPropagation, but if the
        // simulated event prevents default then we do the same on the donor.
-       var e = jQuery.extend( new jQuery.Event(), event, { type: type, originalEvent: {} } );
+       var e = jQuery.extend( 
+               new jQuery.Event(), 
+               event, 
+               { type: type, isSimulated: true, originalEvent: {} }
+       );
        if ( bubble ) {
                jQuery.event.trigger( e, null, elem );
        } else {