expando

property, "jQuery" + (new Date (). getTime (). The value is an integer and increases progressively from zero. However, the UUID is always attached to an object. If the object is a window, isn't it a global pollution? Therefore, when jQuery internally determines that it is a window object, it is mapped to an empty object called windowData, add the UUID to it. With UUID, when we access the cache system for the first time, an empty object (cache body) will be opened in the $. cache object for stor

// used to track events that have never been used and optimize jQuery. event. global [type] = true ;}}}; Note that objects and arrays are referenced! For example, the code that saves event data to the cache: handlers = events[ type ] = [];if ( selector ) { handlers.splice( handlers.delegateCount++, 0, handleObj );} else { handlers.push( handleObj );} If handlers is changed, events [type] will change at the same time. Datatev is the object for managing cache: The job is to create an attribute

expression (while) at the beginning of the loop, tests the expression at the end of the loop (Do/while), operates on each property of the object (For/in), and loops (for) controlled by the counter. such as: For...in loop (1) Traversal object properties: var myObject = new Object (); Myobject.name = "James"; Myobject.age = "22"; Myobject.phone = "555 1234";//enumeration (looping) All properties of the object for (prop in myObject) {//Traverse MyObject All properties (

JQuery selector source code (8): addCombinator function, Function addCombinator (matcher, combinator, base) 1. Source CodeCopy codeThe Code is as follows:Function addCombinator (matcher, combinator, base ){Var dir = combinator. dir, checkNonElements = base Dir = "parentNode", doneName = done ++; Return combinator. first?// Check against closest ancestor/preceding elementFunction (elem, context, xml ){While (elem = elem [dir]) {If (elem. nodeType = 1 | checkNonElements ){Return matcher (elem, con

then from the DOM element The attached property is removed and output. Because we do not attach objects directly to the DOM element, given the problem of IE6, IE7 garbage Collection on object references on DOM element, we use global cache and append a UID to the DOM element. The implementation method is as follows: $ = function () { var expando = "JQuery" + ("6" + mathrandom ()) Replace (/\d/g, "); var globalcache = {}; var uuid = 0;

function Addcombinator (Matcher, Combinator, Base) 1, source code Copy Code code as follows: function Addcombinator (Matcher, Combinator, base) { var dir = combinator.dir, checknonelements = base dir = = = "ParentNode", donename = done++; Return Combinator.first?Check against closest ancestor/preceding elementfunction (elem, context, XML) {while ((Elem = Elem[dir])) {if (Elem.nodetype = = 1 | | checknonelements) {Return Matcher (Elem, context, XML);}}} : Check Against all an

function Addcombinator (Matcher, Combinator, Base)1. Source Codefunction Addcombinator (Matcher, Combinator, base) {var dir = combinator.dir, checknonelements = base dir = = = "Pa Rentnode ", Donename = Done++;return combinator.first?//Check against closest ancestor/preceding Elementfunction (Elem, C Ontext, XML) {while ((Elem = Elem[dir]) {if (Elem.nodetype = = = 1 | | checknonelements) {return Matcher (Elem, Context, XML) ;}}} ://Check against All ancestor/preceding elementsfunction (elem, con

JQuery selector code description-addCombinator Function Function addCombinator (matcher, combinator, base) 1. Source Code function addCombinator(matcher, combinator, base) {var dir = combinator.dir, checkNonElements = base dir === parentNode, doneName = done++;return combinator.first ?// Check against closest ancestor/preceding elementfunction(elem, context, xml) {while ((elem = elem[dir])) {if (elem.nodeType === 1 || checkNonElements) {return matcher(elem, context, xml);}}} :// Check against al

){If (matcher (elem, context, xml )){Return true;}}}} Else {While (elem = elem [dir]) {If (elem. nodeType = 1 | checkNonElements ){OuterCache = elem [expando] | (elem [expando] = {});If (cache = outerCache [dir]) Cache [0] === dirkey ){If (data = cache [1]) = true| Data === cachedruns ){Return data = true;}} Else {Cache = outerCache [dir] = [dirkey];Cache [1] = matcher (elem, context, xml)| Cachedruns;If (

For jQuery'sData Cache, I believe everyone will not be unfamiliar,JQuery Cache SystemNot only usedDOM Element,Animation and eventAnd so on. Therefore, in actual applications, we often need to cache some data for elements, which are often closely related to DOM elements. Because DOM elements (nodes) are also objects, we can directly extend the attributes of DOM elements. However, adding custom attributes and excessive data to DOM elements may causeMemory leakageSo we should try to avoid this. The

jquery1.4 jquery1.4 Download The jQuery1.4 is used here, why use 1.4 because 1.4 many features are relatively easy to analyze without adding them. The implementation of this data is extended in the jquery static function, and we usually ($ (' #data '). Data (' Tudou ', ' abc ') calls the data on the jquery prototype, and the data on the prototype is then called under jquery static Data method implementation. Jquery.extend ({cache:{},expando:expando,//thefollowingelementsthrow Uncatchableexcepti

, Globalcache = {}, Doc = Window.document, The Consortium =!! Doc.addeventlistener, expando = ' Snandy ' + (' +math.random ()). Replace (/\d/g, '), AddListener = The consortium? Function (el, type, fn) {El.addeventlistener (type, FN, false);}: Function (el, type, fn) {el.attachevent (' on ' + type, fn);}, RemoveListener = The consortium? Function (el, type, fn) {El.removeeventlistener (type, FN, false);}: Function (el, type, fn) {el.detachev