JQuery source code analysis-03 construct a jQuery object-tool function _ jquery

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JQuery source code analysis-03 construct a jQuery object-tool function. For more information, see. Author: nuysoft/high cloud QQ: 47214707 EMail: nuysoft@gmail.com
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For the directory of the jQuery source code analysis series, see examples.
3.4 other static tool Functions

The Code is as follows:

// Extended tool Functions
JQuery. extend ({
// Release $'s jQuery Control
// Many JavaScript libraries use $ as the name of a function or variable, as is jQuery.
// In jQuery, $ is just the alias of jQuery, so all functions can be guaranteed even if $ is not used.
// If we need to use another JavaScript library other than jQuery, we can return control to the library by calling $. noConflict.
// By passing the parameter true to this method, we can return the control of $ and jQuery to another JavaScript library.
NoConflict: function (deep ){
// Hand over the control of $
If (window. $ === jQuery ){
Window. $ =_$;
// Hand over control of jQuery
If (deep & window. jQuery === jQuery ){
Window. jQuery = _ jQuery;
Return jQuery;
// Is the DOM ready to be used? Set to true once it occurs.
IsReady: false,
// A counter to track how many items to wait for before
// The ready event fires. See #6781
// A counter used to track the number of waits before the ready event starts
ReadyWait: 1,
// Hold (or release) the ready event
// Wait or trigger
HoldReady: function (hold ){
If (hold ){
JQuery. readyWait ++;
} Else {
JQuery. ready (true );
// Handle when the DOM is ready
// Handle for document loading
Ready: function (wait ){
// Either a released hold or an DOMready/load event and not yet ready
If (wait === true &&! -- JQuery. readyWait) | (wait! = True &&! JQuery. isReady )){
// Make sure body exists, at least, in case IE gets a little overzealous (ticket #5443 ).
// Ensure that document. body exists
If (! Document. body ){
Return setTimeout (jQuery. ready, 1 );
// Remember that the DOM is ready
JQuery. isReady = true;
// If a normal DOM Ready event fired, decrement, and wait if need be
If (wait! = True & -- jQuery. readyWait> 0 ){
// If there are functions bound, to execute
ReadyList. resolveWith (document, [jQuery]);
// Trigger any bound ready events
If (jQuery. fn. trigger ){
JQuery (document). trigger ("ready"). unbind ("ready ");
// Initialize the readyList event processing function queue
// Compatible with the differences between events bound to different views
BindReady: function (){
If (readyList ){
ReadyList = jQuery. _ Deferred ();
// Catch cases where $ (document). ready () is called after
// Browser event has already occurred.
If (document. readyState = "complete "){
// Handle it asynchronously to allow scripts the opportunity to delay ready
Return setTimeout (jQuery. ready, 1 );
// Mozilla, Opera and webkit nightlies currently support this event
// Compatible event, by detecting the functional features of the browser, rather than sniffing the browser
If (document. addEventListener ){
// Use the handy event callback
// Use a fast loading completion event
Document. addEventListener ("DOMContentLoaded", DOMContentLoaded, false );
// A fallback to window. onload, that will always work
// Register the window. onload callback function
Window. addEventListener ("load", jQuery. ready, false );
// If IE event model is used
} Else if (document. attachEvent ){
// Ensure firing before onload,
// Maybe late but safe also for iframes
// Make sure that onreadystatechange is triggered before onload, which may be slower but safer for iframes
Document. attachEvent ("onreadystatechange", DOMContentLoaded );
// A fallback to window. onload, that will always work
// Register the window. onload callback function
Window. attachEvent ("onload", jQuery. ready );
// If IE and not a frame
// Continually check to see if the document is ready
Var toplevel = false;
Try {
Toplevel = window. frameElement = null;
} Catch (e ){}
If (document.doc umentElement. doScroll & toplevel ){
DoScrollCheck ();
// See test/unit/core. js for details concerning isFunction.
// Since version 1.3, DOM methods and functions like alert
// Aren't supported. They return false on IE (#2968 ).
// Function?
IsFunction: function (obj ){
Return jQuery. type (obj) = "function ";
// Array or not
// If the browser has built-in Array. isArray implementation, use the browser's own implementation method,
// Otherwise, convert the object to String to see if it is "[object Array]".
IsArray: Array. isArray | function (obj ){
Return jQuery. type (obj) = "array ";
// A crude way of determining if an object is a window
// You can determine whether the setInterval attribute is a window object.
IsWindow: function (obj ){
Return obj & typeof obj = "object" & "setInterval" in obj;
// Whether it is a reserved word NaN
IsNaN: function (obj ){
// Equals null or not a number or calls window. isNaN to determine
Return obj = null |! Rdigit. test (obj) | isNaN (obj );
// Obtain the object type
Type: function (obj ){
// Create an object using the core API without the new Keyword
// Normal functions do not work
// Call the Object. prototype. toString method to generate a string in the format of "[object Xxx ]"
// Class2type ["[object" + name + "]"] = name. toLowerCase ();
Return obj = null?
String (obj ):
Class2type [toString. call (obj)] | "object ";
// Check whether obj is a pure Object (an Object created through "{}" or "new Object)
// Console.info ($. isPlainObject ({}); // true
// Lele.info ($. isPlainObject (''); // false
// Console.info ($. isPlainObject (document. location); // true
// Console.info ($. isPlainObject (document); // false
// Lele.info ($. isPlainObject (new Date (); // false
// Console.info ($. isPlainObject (); // false
// IsPlainObject analysis and reconstruction http://www.jb51.net/article/25047.htm
// An http://www.cnblogs.com/phpmix/articles/1733599.html for jQuery. isPlainObject ()
IsPlainObject: function (obj ){
// Must be an Object.
// Because of IE, we also have to check the presence of the constructor property.
// Make sure that DOM nodes and window objects don't pass through, as well
// It must be an object
// Because an Invalid Pointer exception is thrown in IE8, the constructor attribute must be checked.
// DOM node and window object, return false
// If obj does not exist or is not of the object type, DOM node, or widnow object, false is directly returned.
// Test the following three possible conditions:
// JQuery. type (obj )! = "Object" type is not an object, ignore
// Obj. nodeType indicates that the DOM node is not a pure object.
// JQuery. isWindow (obj) considers window as not a pure object
If (! Obj | jQuery. type (obj )! = "Object" | obj. nodeType | jQuery. isWindow (obj )){
Return false;
// Not own constructor property must be Object
// Test the constructor attributes
// Constructor has constructor, but is not its own attribute (inherited by prototype ),
If (obj. constructor &&
! HasOwn. call (obj, "constructor ")&&
! HasOwn. call (obj. constructor. prototype, "isPrototypeOf ")){
Return false;
// Own properties are enumerated firstly, so to speed up,
// If last one is own, then all properties are own.
Var key;
For (key in obj ){}
// Key = undefined and no attributes exist. It is regarded as a simple pure object.
// HasOwn. call (obj, key) the attribute key is not empty, and the object of the attribute key itself (that is, it is not inherited by prototype)
Return key = undefined | hasOwn. call (obj, key );
// Whether the object is null
IsEmptyObject: function (obj ){
For (var name in obj ){
Return false;
Return true;
// Throw an exception
Error: function (msg ){
Throw msg;
// Parse JSON
// ParseJSON converts a string into a JSON object.
// We generally use eval. ParseJSON encapsulates this operation, but eval is used as the final method.
// Because JSON serialization and deserialization APIs are added to the latest JavaScript standard.
// If the browser supports this standard, the two APIs are implemented using Native Code in the JS engine, and the efficiency is certainly much higher than that of eval.
// Currently, both Chrome and Firefox4 support this API.
ParseJSON: function (data ){
If (typeof data! = "String" |! Data ){
Return null;
// Make sure leading/trailing whitespace is removed (IE can't handle it)
Data = jQuery. trim (data );
// Attempt to parse using the native JSON parser first
// Native json api. Deserialization is JSON. stringify (object)
If (window. JSON & window. JSON. parse ){
Return window. JSON. parse (data );
// Make sure the incoming data is actual JSON
// Logic borrowed from http://json.org/json2.js
//... Check the validity of the string roughly.
If (rvalidchars. test (data. replace (rvalidescape ,"@")
. Replace (rvalidtokens, "]")
. Replace (rvalidbraces ,""))){
Return (new Function ("return" + data ))();
JQuery. error ("Invalid JSON:" + data );
// Cross-browser xml parsing
// (Xml & tmp used internally)
// Parse XML cross-browser
// ParseXML functions are encapsulated by standard APIs and IE.
// The standard API is a DOMParser object.
// IE uses the ActiveXObject object of Microsoft. XMLDOM.
ParseXML: function (data, xml, tmp ){
If (window. DOMParser) {// Standard XML Parser
Tmp = new DOMParser ();
Xml = tmp. parseFromString (data, "text/xml ");
} Else {// XML Parser for IE
Xml = new ActiveXObject ("Microsoft. XMLDOM ");
Xml. async = "false ";
Xml. loadXML (data );
Tmp = xml.doc umentElement;
If (! Tmp |! Tmp. nodeName | tmp. nodeName = "parsererror "){
JQuery. error ("Invalid XML:" + data );
Return xml;
// No operation function
Noop: function (){},
// Evaluates a script in a global context
// Workarounds based on findings by Jim Driscoll
// Http://weblogs.java.net/blog/driscoll/archive/2009/09/08/eval-javascript-global-context
// The globalEval function loads a script into the global context (window.
// You can use window.exe cScript in IE.
// Eval is required for other browsers.
// Because the entire jQuery code is an anonymous function, the current context is jQuery. To set the context to window, use globalEval.
GlobalEval: function (data ){
// Data is not empty
If (data & rnotwhite. test (data )){
// We use execScript on Internet Explorer
// We use an anonymous function so that context is window
// Rather than jQuery in Firefox
(Window.exe cScript | function (data ){
Window ["eval"]. call (window, data );
}) (Data );
// Determine whether the node name is the same
NodeName: function (elem, name ){
// Case insensitive
Return elem. nodeName & elem. nodeName. toUpperCase () === name. toUpperCase ();
// Args is for internal usage only
// Traverse objects or Arrays
Each: function (object, callback, args ){
Var name, I = 0,
Length = object. length,
IsObj = length = undefined | jQuery. isFunction (object );
// If The args parameter exists, call apply and set the context to the object Currently traversed. The args
If (args ){
If (isObj ){
For (name in object ){
If (callback. apply (object [name], args) === false ){
} Else {
For (; I <length ;){
If (callback. apply (object [I ++], args) === false ){
// A special, fast, case for the most common use of each
// If args is not set, call is called. The context is set to the object Currently traversed, and the parameters are set to key/index and value.
} Else {
If (isObj ){
For (name in object ){
If (callback. call (object [name], name, object [name]) === false ){
} Else {
For (; I <length ;){
If (callback. call (object [I], I, object [I ++]) === false ){
Return object;
// Use native String. trim function wherever possible
// Use the local String. trim method as much as possible. Otherwise, the leading space is filtered first, and then the Ending Space is filtered.
Trim: trim?
Function (text ){
Return text = null?
Trim. call (text );
// Otherwise use our own trimming functionality
Function (text ){
Return text = null?
Text. toString (). replace (trimLeft, ""). replace (trimRight ,"");
// Results is for internal usage only
// Convert a pseudo array to an array
MakeArray: function (array, results ){
Var ret = results | [];
If (array! = Null ){
// The window, strings (and functions) also have 'length'
// The extra typeof function check is to prevent crashes
// In Safari 2 (See: #3039)
// Tweaked logic slightly to handle Blackberry 4.7 RegExp issues #6930
// There are a lot of browser compatibility tests, which really hurt
Var type = jQuery. type (array );
// Test: whether the length attribute, String, function, and regular expression are available
// Not an array, not even a pseudo Array
If (array. length = null
| Type = "string"
| Type = "function"
| Type = "regexp"
| JQuery. isWindow (array )){
Push. call (ret, array );
} Else {
// $. Type ($ ('P') // object
JQuery. merge (ret, array );
Return ret;
InArray: function (elem, array ){
// Whether there is a localized Array. prototype. indexOf
If (indexOf ){
// Directly call Array. prototype. indexOf
Return indexOf. call (array, elem );
// Traverse the array to check whether there are completely equal elements and return the subscript
// Tips for loop: store array. length in the length variable, which can reduce the number of scope searches.
For (var I = 0, length = array. length; I <length; I ++ ){
If (array [I] === elem ){
Return I;
// If-1 is returned, it indicates it is not in the array
// Merge the array second into array first
Merge: function (first, second ){
Var I = first. length ,//
J = 0;
// If the length attribute of second is of the Number type, process second as an array.
If (typeof second. length = "number "){
For (var l = second. length; j <l; j ++ ){
First [I ++] = second [j];
} Else {
// Traverse second and add non-undefined values to first
While (second [j]! = Undefined ){
First [I ++] = second [j ++];
// Modify the length attribute of first because first may not be a real array.
First. length = I;
Return first;
// Filter the array and return a new array. The value is retained when callback returns true. If inv is true, callback returns false.
Grep: function (elems, callback, inv ){
Var ret = [], retVal;
Inv = !! Inv;
// Go through the array, only saving the items
// That pass the validator function
// Traverses the array and only retains the elements that pass the verification function callback.
For (var I = 0, length = elems. length; I <length; I ++ ){
// Here, the callback parameter list is: value, index, consistent with the each habit
RetVal = !! Callback (elems [I], I );
// Whether to reverse select
If (inv! = RetVal ){
Ret. push (elems [I]);
Return ret;
// Arg is for internal usage only
// Convert the elements/attributes of an array or elems object into a new array
Map: function (elems, callback, arg ){
Var value, key, ret = [],
I = 0,
Length = elems. length,
// Jquery objects are treated as arrays
// Check whether elems is a pseudo Array
// 1. Treat jQuery objects as Arrays
// 2. Check whether the length attribute exists. length is equal to 0, or whether the first and last elements exist, or jQuery. isArray returns true.
IsArray = elems instanceof jQuery
| Length! = Undefined & typeof length = "number"
& (Length> 0 & elems [0] & elems [length-1]) | length = 0 | jQuery. isArray (elems ));
// It is the difference between arrays or objects. Only the Traversal method is different and there is no other difference.
// Go through the array, translating each of the items to their
// Traverses the array and calls callback for each element. The returned value is not null and stored in ret.
If (isArray ){
For (; I <length; I ++ ){
// Run callback. The parameters are value, index, and arg.
Value = callback (elems [I], I, arg );
// If null is returned, it is ignored (the function without return value will return undefined)
If (value! = Null ){
Ret [ret. length] = value;
// Go through every key on the object,
// Traverses the object and calls callback for each attribute. The returned value is not null and stored in ret.
} Else {
For (key in elems ){
// Run callback. The parameters are value, key, and arg.
Value = callback (elems [key], key, arg );
// Same as above
If (value! = Null ){
Ret [ret. length] = value;
// Flatten any nested arrays
// Flatten the nested Array
// Concat:
// If an item is an array, add its content to the end.
// If the project is not an array, add it as a single array element to the end of the array.
Return ret. concat. apply ([], ret );
// A global GUID counter for objects
Guid: 1,
// Bind a function to a context, optionally partially applying any
// Arguments.
// Proxy method: Specify the context (this) for fn)
// JQuery. proxy (function, context)
// JQuery. proxy (context, name)
Proxy: function (fn, context ){
// If context is a string, set context to fn and fn to fn [context]
// Set the context of the fn context method to fn (which is not the default ??? TODO)
If (typeof context = "string "){
Var tmp = fn [context];
Context = fn;
Fn = tmp;
// Quick check to determine if target is callable, in the spec
// This throws a TypeError, but we will just return undefined.
// Quickly test whether the fn is callable (that is, a function). In the instructions of this document, a TypeError is thrown,
// But only undefined is returned here
If (! JQuery. isFunction (fn )){
Return undefined;
// Simulated bind
Var args = slice. call (arguments, 2), // remove fn, context from the parameter list
Proxy = function (){
// Set the context to context and parameters.
Return fn. apply (context, args. concat (slice. call (arguments )));
// Set the guid of unique handler to the same of original handler, so it can be removed
// Unify the guid so that the proxy can be removed
Proxy. guid = fn. guid = fn. guid | proxy. guid | jQuery. guid ++;
Return proxy;
// Mutifunctional method to get and set values to a collection
// The value/s can be optionally by executed if its a function
// A multi-function that reads or sets the property value of a set. If the value is a function, it is executed.
// Fn: jQuery.fn.css, jQuery. fn. attr, jQuery. fn. prop
Access: function (elems, key, value, exec, fn, pass ){
Var length = elems. length;
// Setting many butes
// Iteration if multiple attributes exist
If (typeof key = "object "){
For (var k in key ){
JQuery. access (elems, k, key [k], exec, fn, value );
Return elems;
// Setting one attribute
// Set only one attribute
If (value! = Undefined ){
// Optionally, function values get executed if exec is true
Exec =! Pass & exec & jQuery. isFunction (value );
For (var I = 0; I <length; I ++ ){
Fn (elems [I], key, exec? Value. call (elems [I], I, fn (elems [I], key): value, pass );
Return elems;
// Getting an attribute
// Read attributes
Return length? Fn (elems [0], key): undefined;
// Obtain convenient functions for the current time
Now: function (){
Return (new Date (). getTime ();
// Use of jQuery. browser is frowned.
// More details: http://docs.jquery.com/Utilities/jQuery.browser
// Do not approve of jQuery. browser. jQuery. support is recommended.
// Information of the browser in use by Navigator
// Navigator. userAgent is a read-only string that declares the value of the user proxy header used by the browser for HTPP requests.
UaMatch: function (ua ){
Ua = ua. toLowerCase ();
// Match each browser in sequence
Var match = rwebkit.exe c (ua) |
Ropera.exe c (ua) |
Rmsie.exe c (ua) |
Ua. indexOf ("compatible") <0 & rmozilla.exe c (ua) |
// Match [1] | ""
// When match [1] is false (null String, null, undefined, 0, etc.), the default value is ""
// Match [2] | "0"
// When match [2] is false (null String, null, undefined, 0, etc.), the default value is "0"
Return {browser: match [1] | "", version: match [2] | "0 "};
// Create a new jQuery copy. The attributes and methods of the copy can be changed, but they do not affect the original jQuery object.
// There are two usage methods:
// 1. Override the jQuery method without damaging the original method
// 2. encapsulation to avoid namespace conflicts and can be used to develop jQuery plug-ins
// It is worth noting that the jQuery. sub () function does not provide true isolation, and all attributes and methods still point to the original jQuery
// If you use this method to develop plug-ins, we recommend that you prioritize the jQuery UI widget project.
Sub: function (){
Function jQuerySub (selector, context ){
Return new jQuerySub. fn. init (selector, context );
JQuery. extend (true, jQuerySub, this); // copy all jQuery attributes and methods to jQuerySub.
JQuerySub. superclass = this;
JQuerySub. fn = jQuerySub. prototype = this ();//
JQuerySub. fn. constructor = jQuerySub;
JQuerySub. sub = this. sub;
JQuerySub. fn. init = function init (selector, context ){
If (context & context instanceof jQuery &&! (Context instanceof jQuerySub )){
Context = jQuerySub (context );
Return jQuery. fn. init. call (this, selector, context, rootjQuerySub );
JQuerySub. fn. init. prototype = jQuerySub. fn;
Var rootjQuerySub = jQuerySub (document );
Return jQuerySub;
// Browser type and version:
// $. Browser. msie/mozilla/webkit/opera
// $. Browser. version
// It is not recommended to sniff the browser type jQuery. browser, but to check the functional features of the browser jQuery. support
// JQuery. browser may be moved to a plug-in the future
Browser :{}

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