jQuery源码解读
/*!
* jQuery JavaScript Library v3.2.1
* https://jquery.com/
*
* Includes Sizzle.js
* https://sizzlejs.com/
*
* Copyright JS Foundation and other contributors
* Released under the MIT license
* https://jquery.org/license
*
* Date: 2017-03-20T18:59Z
*/
( function( global, factory ) {
/**
*Carol:global factory对象是从哪里来的？
*/
"use strict";
//Carol:设立严格模式的目的
//1.严格模式用于函数的开头而非文件的开头
//2.严格模式可以消除javascript的一些不合理，不严谨之处，减少怪异行为
//3.消除代码的不安全之处，保证代码的运行
//4.提高编译器效率，增强运行速度
//5.为未来新版本的javascript做好铺垫
if ( typeof module === "object" && typeof module.exports === "object" ) {
// For CommonJS and CommonJS-like environments where a proper `window`
// is present, execute the factory and get jQuery.
// For environments that do not have a `window` with a `document`
// (such as Node.js), expose a factory as module.exports.
// This accentuates the need for the creation of a real `window`.
// e.g. var jQuery = require("jquery")(window);
// See ticket #14549 for more info.
module.exports = global.document ?
factory( global, true ) :
function( w ) {
if ( !w.document ) {
throw new Error( "jQuery requires a window with a document" );
}
return factory( w );
};
} else {
factory( global );
}
// Pass this if window is not defined yet
} )( typeof window !== "undefined" ? window : this, function( window, noGlobal ) {
/*
* Carol: 匿名函数形式
* (function(global,factory){})(typeof window !== "undefined" ? window : this,function(){});
*/
// Edge <= 12 - 13+, Firefox <=18 - 45+, IE 10 - 11, Safari 5.1 - 9+, iOS 6 - 9.1
// throw exceptions when non-strict code (e.g., ASP.NET 4.5) accesses strict mode
// arguments.callee.caller (trac-13335). But as of jQuery 3.0 (2016), strict mode should be common
// enough that all such attempts are guarded in a try block.
"use strict";
var arr = [];//定义一个数组
var document = window.document;
var getProto = Object.getPrototypeOf;//拿到返回指定对象原型的方法
var slice = arr.slice;//拿到截取数组的方法
var concat = arr.concat;//拿到连接数组的方法
var push = arr.push;//拿到把元素加到数组中的方法
var indexOf = arr.indexOf;//拿到判断某元素是否在数组中的方法
var class2type = {};//定义一个对象
var toString = class2type.toString;//拿到一个对象的toString（）方法
var hasOwn = class2type.hasOwnProperty;//拿到 判断一个对象自身（不包括对象原型）是否含有某个属性的方法。返回值是true/false
var fnToString = hasOwn.toString;//把判断对象自身是否含有某个属性的方法变成字符串
var ObjectFunctionString = fnToString.call( Object );
/**
* Carol:返回值是"function Object() { [native code] }" 使用call来返回该对象的构造器函数然后再用toString返回字符串形式
*/
var support = {};//定义一个对象
//Carol:eval(string) 可以计算字符串中的合理的表达式或者语句
//表达式eval('1+1')---->2 语句 eval('123')---->123
function DOMEval( code, doc ) {
doc = doc || document;
var script = doc.createElement( "script" );//创建<script></script>
script.text = code;//<script>code参数的内容</script>
doc.head.appendChild( script ).parentNode.removeChild( script );
//Carol:为什么这个代码块先加到head中然后又从head中移除呢？
}
/* global Symbol */
// Defining this global in .eslintrc.json would create a danger of using the global
// unguarded in another place, it seems safer to define global only for this module
var
version = "3.2.1",//定义版本号
// Define a local copy of jQuery
jQuery = function( selector, context ) {//Carol:这个jquery对象是用来初始化构造器的?
// The jQuery object is actually just the init constructor 'enhanced'
// Need init if jQuery is called (just allow error to be thrown if not included)
return new jQuery.fn.init( selector, context );
},
// Support: Android <=4.0 only
// Make sure we trim BOM and NBSP
rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g,
/**
*Carol:这个正则表达式用于去除非法字符串以及" "
* ^匹配一个输入或者一行的开头
* $匹配一个输入或者一行的结尾
* \s匹配一个空白字符 如\n(换行) \r(回车) \f(换页) \t(制表) \v(垂直制表符)
* +匹配前面元字符一次或者多次 /ac+/将匹配 ac acc accc
* |或者
* g:匹配全局作用域
* \uFEFF ： 某些软件，在以utf-8编码方式保存文件时，会在文件开始的地方插入三个看不见的字符(0xEF 0xBB 0xBF 即BOM)
* 转码后是\uFEFF 因此需要去掉这个字符
* \xA0: 去掉" "
*/
// Matches dashed string for camelizing
rmsPrefix = /^-ms-/,//匹配以"-ms-"开始的字符
rdashAlpha = /-([a-z])/g,//全局匹配-小写字母比如 -q -qwer只能匹配到-q -qw-er可以匹配到-q -e
// Used by jQuery.camelCase as callback to replace()
fcamelCase = function( all, letter ) {
return letter.toUpperCase();
};//jQuery.camelCase要用fcamelCase这个方法来代替回调函数
jQuery.fn = jQuery.prototype = {
// The current version of jQuery being used
jquery: version,//前面定义的3.2.1
constructor: jQuery,//前面定义的function(selector,context){...}
// The default length of a jQuery object is 0
length: 0,//jquery对象的默认长度是0
toArray: function() {
return slice.call( this );//前面定义的[].slice.call(this) 返回值是一个空数组
},
// Get the Nth element in the matched element set OR
// Get the whole matched element set as a clean array
get: function( num ) {
// Return all the elements in a clean array
if ( num == null ) {
return slice.call( this );
}
// Return just the one element from the set
return num < 0 ? this[ num + this.length ] : this[ num ];
/**
*Carol 以一个页面中的get方法调用，加入一个页面中有20个div元素
* $('div').get()返回值是一个数组，包含所有依据选择器查到的元素
* $('div').get(3)拿到第四个div元素
* $('div').get(-2)拿到倒数第三个元素
*/
},
// Take an array of elements and push it onto the stack
// (returning the new matched element set)
pushStack: function( elems ) {
// Build a new jQuery matched element set
var ret = jQuery.merge( this.constructor(), elems );
//Carol: 拿到的是之前定义的空的jQuery对象
jQuery = function( selector, context ) {
//The jQuery object is actually just the init constructor 'enhanced'
// Need init if jQuery is called (just allow error to be thrown if not included)
return new jQuery.fn.init( selector, context );
},//Carol:初始化jQuery的构造器
// Add the old object onto the stack (as a reference)
ret.prevObject = this;//将当前对象加入到这个空的jQuery的旧的对象里面
// Return the newly-formed element set
return ret;//返回改变之后的对象
},
// Execute a callback for every element in the matched set.
each: function( callback ) {
return jQuery.each( this, callback );
},
map: function( callback ) {
return this.pushStack( jQuery.map( this, function( elem, i ) {
return callback.call( elem, i, elem );
} ) );
},
slice: function() {
return this.pushStack( slice.apply( this, arguments ) );
},
first: function() {
return this.eq( 0 );
},
last: function() {
return this.eq( -1 );
},
eq: function( i ) {
var len = this.length,
j = +i + ( i < 0 ? len : 0 );
return this.pushStack( j >= 0 && j < len ? [ this[ j ] ] : [] );
},
end: function() {
return this.prevObject || this.constructor();
},
// For internal use only.
// Behaves like an Array's method, not like a jQuery method.
push: push,
sort: arr.sort,
splice: arr.splice
};
jQuery.extend = jQuery.fn.extend = function() {
var options, name, src, copy, copyIsArray, clone,
target = arguments[ 0 ] || {},
i = 1,
length = arguments.length,
deep = false;
// Handle a deep copy situation
if ( typeof target === "boolean" ) {
deep = target;
// Skip the boolean and the target
target = arguments[ i ] || {};
i++;
}
// Handle case when target is a string or something (possible in deep copy)
if ( typeof target !== "object" && !jQuery.isFunction( target ) ) {
target = {};
}
// Extend jQuery itself if only one argument is passed
if ( i === length ) {
target = this;
i--;
}
for ( ; i < length; i++ ) {
// Only deal with non-null/undefined values
if ( ( options = arguments[ i ] ) != null ) {
// Extend the base object
for ( name in options ) {
src = target[ name ];
copy = options[ name ];
// Prevent never-ending loop
if ( target === copy ) {
continue;
}
// Recurse if we're merging plain objects or arrays
if ( deep && copy && ( jQuery.isPlainObject( copy ) ||
( copyIsArray = Array.isArray( copy ) ) ) ) {
if ( copyIsArray ) {
copyIsArray = false;
clone = src && Array.isArray( src ) ? src : [];
} else {
clone = src && jQuery.isPlainObject( src ) ? src : {};
}
// Never move original objects, clone them
target[ name ] = jQuery.extend( deep, clone, copy );
// Don't bring in undefined values
} else if ( copy !== undefined ) {
target[ name ] = copy;
}
}
}
}
// Return the modified object
return target;
};
jQuery.extend( {
// Unique for each copy of jQuery on the page
expando: "jQuery" + ( version + Math.random() ).replace( /\D/g, "" ),
// Assume jQuery is ready without the ready module
isReady: true,
error: function( msg ) {
throw new Error( msg );
},
noop: function() {},
isFunction: function( obj ) {
return jQuery.type( obj ) === "function";
},
isWindow: function( obj ) {
return obj != null && obj === obj.window;
},
isNumeric: function( obj ) {
// As of jQuery 3.0, isNumeric is limited to
// strings and numbers (primitives or objects)
// that can be coerced to finite numbers (gh-2662)
var type = jQuery.type( obj );
return ( type === "number" || type === "string" ) &&
// parseFloat NaNs numeric-cast false positives ("")
// ...but misinterprets leading-number strings, particularly hex literals ("0x...")
// subtraction forces infinities to NaN
!isNaN( obj - parseFloat( obj ) );
},
isPlainObject: function( obj ) {
var proto, Ctor;
// Detect obvious negatives
// Use toString instead of jQuery.type to catch host objects
if ( !obj || toString.call( obj ) !== "[object Object]" ) {
return false;
}
proto = getProto( obj );
// Objects with no prototype (e.g., `Object.create( null )`) are plain
if ( !proto ) {
return true;
}
// Objects with prototype are plain iff they were constructed by a global Object function
Ctor = hasOwn.call( proto, "constructor" ) && proto.constructor;
return typeof Ctor === "function" && fnToString.call( Ctor ) === ObjectFunctionString;
},
isEmptyObject: function( obj ) {
/* eslint-disable no-unused-vars */
// See https://github.com/eslint/eslint/issues/6125
var name;
for ( name in obj ) {
return false;
}
return true;
},
type: function( obj ) {
if ( obj == null ) {
return obj + "";
}
// Support: Android <=2.3 only (functionish RegExp)
return typeof obj === "object" || typeof obj === "function" ?
class2type[ toString.call( obj ) ] || "object" :
typeof obj;
},
// Evaluates a script in a global context
globalEval: function( code ) {
DOMEval( code );
},
// Convert dashed to camelCase; used by the css and data modules
// Support: IE <=9 - 11, Edge 12 - 13
// Microsoft forgot to hump their vendor prefix (#9572)
camelCase: function( string ) {
return string.replace( rmsPrefix, "ms-" ).replace( rdashAlpha, fcamelCase );
},
each: function( obj, callback ) {
var length, i = 0;//Carol:定义长度和循环索引
if ( isArrayLike( obj ) ) {
length = obj.length;//将数组obj的长度赋值给length
for ( ; i < length; i++ ) {//循环遍历数组
if ( callback.call( obj[ i ], i, obj[ i ] ) === false ) {
break;//终止整个循环
}
}
} else {
for ( i in obj ) {//循环对象obj中的属性
if ( callback.call( obj[ i ], i, obj[ i ] ) === false ) {
break;//终止整个循环
}
}
}
return obj;//返回调用callback函数之后的对象或者数组
},
// Support: Android <=4.0 only
trim: function( text ) {
return text == null ?
"" :
( text + "" ).replace( rtrim, "" );
},
// results is for internal usage only
makeArray: function( arr, results ) {
var ret = results || [];
if ( arr != null ) {
if ( isArrayLike( Object( arr ) ) ) {
jQuery.merge( ret,
typeof arr === "string" ?
[ arr ] : arr
);
} else {
push.call( ret, arr );
}
}
return ret;
},
inArray: function( elem, arr, i ) {
return arr == null ? -1 : indexOf.call( arr, elem, i );
},
// Support: Android <=4.0 only, PhantomJS 1 only
// push.apply(_, arraylike) throws on ancient WebKit
merge: function( first, second ) {
var len = +second.length,//拿到第二个参数的长度
j = 0,//循环索引
i = first.length;//拿到第一个参数的长度
for ( ; j < len; j++ ) {//循环第二个数组，把第二个数组中的元素追加到第一个数组里面
first[ i++ ] = second[ j ];
}
first.length = i;
//把第一个数组的长度设置为追加元素之后的总长度
//Carol:即使不加这一句代码，最终返回的追加后的数组元素和长度也不会出错，为什么要加这一句呢？仅仅是因为规范吗？
return first;//返回追加后的数组
},
grep: function( elems, callback, invert ) {
var callbackInverse,
matches = [],
i = 0,
length = elems.length,
callbackExpect = !invert;
// Go through the array, only saving the items
// that pass the validator function
for ( ; i < length; i++ ) {
callbackInverse = !callback( elems[ i ], i );
if ( callbackInverse !== callbackExpect ) {
matches.push( elems[ i ] );
}
}
return matches;
},
// arg is for internal usage only
map: function( elems, callback, arg ) {
var length, value,
i = 0,
ret = [];
// Go through the array, translating each of the items to their new values
if ( isArrayLike( elems ) ) {
length = elems.length;
for ( ; i < length; i++ ) {
value = callback( elems[ i ], i, arg );
if ( value != null ) {
ret.push( value );
}
}
// Go through every key on the object,
} else {
for ( i in elems ) {
value = callback( elems[ i ], i, arg );
if ( value != null ) {
ret.push( value );
}
}
}
// Flatten any nested arrays
return concat.apply( [], ret );
},
// A global GUID counter for objects
guid: 1,
// Bind a function to a context, optionally partially applying any
// arguments.
proxy: function( fn, context ) {
var tmp, args, proxy;
if ( typeof context === "string" ) {
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.
if ( !jQuery.isFunction( fn ) ) {
return undefined;
}
// Simulated bind
args = slice.call( arguments, 2 );
proxy = function() {
return fn.apply( context || this, args.concat( slice.call( arguments ) ) );
};
// Set the guid of unique handler to the same of original handler, so it can be removed
proxy.guid = fn.guid = fn.guid || jQuery.guid++;
return proxy;
},
now: Date.now,
// jQuery.support is not used in Core but other projects attach their
// properties to it so it needs to exist.
support: support
} );
if ( typeof Symbol === "function" ) {
jQuery.fn[ Symbol.iterator ] = arr[ Symbol.iterator ];
}
// Populate the class2type map
jQuery.each( "Boolean Number String Function Array Date RegExp Object Error Symbol".split( " " ),
function( i, name ) {
class2type[ "[object " + name + "]" ] = name.toLowerCase();
} );
function isArrayLike( obj ) {
// Support: real iOS 8.2 only (not reproducible in simulator)
// `in` check used to prevent JIT error (gh-2145)
// hasOwn isn't used here due to false negatives
// regarding Nodelist length in IE
var length = !!obj && "length" in obj && obj.length,
type = jQuery.type( obj );
if ( type === "function" || jQuery.isWindow( obj ) ) {
return false;
}
return type === "array" || length === 0 ||
typeof length === "number" && length > 0 && ( length - 1 ) in obj;
}
var Sizzle =
/*!
* Sizzle CSS Selector Engine v2.3.3
* https://sizzlejs.com/
*
* Copyright jQuery Foundation and other contributors
* Released under the MIT license
* http://jquery.org/license
*
* Date: 2016-08-08
*/
(function( window ) {
var i,
support,
Expr,
getText,
isXML,
tokenize,
compile,
select,
outermostContext,
sortInput,
hasDuplicate,
// Local document vars
setDocument,
document,
docElem,
documentIsHTML,
rbuggyQSA,
rbuggyMatches,
matches,
contains,
// Instance-specific data
expando = "sizzle" + 1 * new Date(),
preferredDoc = window.document,
dirruns = 0,
done = 0,
classCache = createCache(),
tokenCache = createCache(),
compilerCache = createCache(),
sortOrder = function( a, b ) {
if ( a === b ) {
hasDuplicate = true;
}
return 0;
},
// Instance methods
hasOwn = ({}).hasOwnProperty,
arr = [],
pop = arr.pop,
push_native = arr.push,
push = arr.push,
slice = arr.slice,
// Use a stripped-down indexOf as it's faster than native
// https://jsperf.com/thor-indexof-vs-for/5
indexOf = function( list, elem ) {
var i = 0,
len = list.length;
for ( ; i < len; i++ ) {
if ( list[i] === elem ) {
return i;
}
}
return -1;
},
booleans = "checked|selected|async|autofocus|autoplay|controls|defer|disabled|hidden|ismap|loop|multiple|open|readonly|required|scoped",
// Regular expressions
// http://www.w3.org/TR/css3-selectors/#whitespace
whitespace = "[\\x20\\t\\r\\n\\f]",
// http://www.w3.org/TR/CSS21/syndata.html#value-def-identifier
identifier = "(?:\\\\.|[\\w-]|[^\0-\\xa0])+",
// Attribute selectors: http://www.w3.org/TR/selectors/#attribute-selectors
attributes = "\\[" + whitespace + "*(" + identifier + ")(?:" + whitespace +
// Operator (capture 2)
"*([*^$|!~]?=)" + whitespace +
// "Attribute values must be CSS identifiers [capture 5] or strings [capture 3 or capture 4]"
"*(?:'((?:\\\\.|[^\\\\'])*)'|\"((?:\\\\.|[^\\\\\"])*)\"|(" + identifier + "))|)" + whitespace +
"*\\]",
pseudos = ":(" + identifier + ")(?:\\((" +
// To reduce the number of selectors needing tokenize in the preFilter, prefer arguments:
// 1. quoted (capture 3; capture 4 or capture 5)
"('((?:\\\\.|[^\\\\'])*)'|\"((?:\\\\.|[^\\\\\"])*)\")|" +
// 2. simple (capture 6)
"((?:\\\\.|[^\\\\()[\\]]|" + attributes + ")*)|" +
// 3. anything else (capture 2)
".*" +
")\\)|)",
// Leading and non-escaped trailing whitespace, capturing some non-whitespace characters preceding the latter
rwhitespace = new RegExp( whitespace + "+", "g" ),
rtrim = new RegExp( "^" + whitespace + "+|((?:^|[^\\\\])(?:\\\\.)*)" + whitespace + "+$", "g" ),
rcomma = new RegExp( "^" + whitespace + "*," + whitespace + "*" ),
rcombinators = new RegExp( "^" + whitespace + "*([>+~]|" + whitespace + ")" + whitespace + "*" ),
rattributeQuotes = new RegExp( "=" + whitespace + "*([^\\]'\"]*?)" + whitespace + "*\\]", "g" ),
rpseudo = new RegExp( pseudos ),
ridentifier = new RegExp( "^" + identifier + "$" ),
matchExpr = {
"ID": new RegExp( "^#(" + identifier + ")" ),
"CLASS": new RegExp( "^\\.(" + identifier + ")" ),
"TAG": new RegExp( "^(" + identifier + "|[*])" ),
"ATTR": new RegExp( "^" + attributes ),
"PSEUDO": new RegExp( "^" + pseudos ),
"CHILD": new RegExp( "^:(only|first|last|nth|nth-last)-(child|of-type)(?:\\(" + whitespace +
"*(even|odd|(([+-]|)(\\d*)n|)" + whitespace + "*(?:([+-]|)" + whitespace +
"*(\\d+)|))" + whitespace + "*\\)|)", "i" ),
"bool": new RegExp( "^(?:" + booleans + ")$", "i" ),
// For use in libraries implementing .is()
// We use this for POS matching in `select`
"needsContext": new RegExp( "^" + whitespace + "*[>+~]|:(even|odd|eq|gt|lt|nth|first|last)(?:\\(" +
whitespace + "*((?:-\\d)?\\d*)" + whitespace + "*\\)|)(?=[^-]|$)", "i" )
},
rinputs = /^(?:input|select|textarea|button)$/i,
rheader = /^h\d$/i,
rnative = /^[^{]+\{\s*\[native \w/,
// Easily-parseable/retrievable ID or TAG or CLASS selectors
rquickExpr = /^(?:#([\w-]+)|(\w+)|\.([\w-]+))$/,
rsibling = /[+~]/,
// CSS escapes
// http://www.w3.org/TR/CSS21/syndata.html#escaped-characters
runescape = new RegExp( "\\\\([\\da-f]{1,6}" + whitespace + "?|(" + whitespace + ")|.)", "ig" ),
funescape = function( _, escaped, escapedWhitespace ) {
var high = "0x" + escaped - 0x10000;
// NaN means non-codepoint
// Support: Firefox<24
// Workaround erroneous numeric interpretation of +"0x"
return high !== high || escapedWhitespace ?
escaped :
high < 0 ?
// BMP codepoint
String.fromCharCode( high + 0x10000 ) :
// Supplemental Plane codepoint (surrogate pair)
String.fromCharCode( high >> 10 | 0xD800, high & 0x3FF | 0xDC00 );
},
// CSS string/identifier serialization
// https://drafts.csswg.org/cssom/#common-serializing-idioms
rcssescape = /([\0-\x1f\x7f]|^-?\d)|^-$|[^\0-\x1f\x7f-\uFFFF\w-]/g,
fcssescape = function( ch, asCodePoint ) {
if ( asCodePoint ) {
// U+0000 NULL becomes U+FFFD REPLACEMENT CHARACTER
if ( ch === "\0" ) {
return "\uFFFD";
}
// Control characters and (dependent upon position) numbers get escaped as code points
return ch.slice( 0, -1 ) + "\\" + ch.charCodeAt( ch.length - 1 ).toString( 16 ) + " ";
}
// Other potentially-special ASCII characters get backslash-escaped
return "\\" + ch;
},
// Used for iframes
// See setDocument()
// Removing the function wrapper causes a "Permission Denied"
// error in IE
unloadHandler = function() {
setDocument();
},
disabledAncestor = addCombinator(
function( elem ) {
return elem.disabled === true && ("form" in elem || "label" in elem);
},
{ dir: "parentNode", next: "legend" }
);
// Optimize for push.apply( _, NodeList )
try {
push.apply(
(arr = slice.call( preferredDoc.childNodes )),
preferredDoc.childNodes
);
// Support: Android<4.0
// Detect silently failing push.apply
arr[ preferredDoc.childNodes.length ].nodeType;
} catch ( e ) {
push = { apply: arr.length ?
// Leverage slice if possible
function( target, els ) {
push_native.apply( target, slice.call(els) );
} :
// Support: IE<9
// Otherwise append directly
function( target, els ) {
var j = target.length,
i = 0;
// Can't trust NodeList.length
while ( (target[j++] = els[i++]) ) {}
target.length = j - 1;
}
};
}
function Sizzle( selector, context, results, seed ) {
var m, i, elem, nid, match, groups, newSelector,
newContext = context && context.ownerDocument,
// nodeType defaults to 9, since context defaults to document
nodeType = context ? context.nodeType : 9;
results = results || [];
// Return early from calls with invalid selector or context
if ( typeof selector !== "string" || !selector ||
nodeType !== 1 && nodeType !== 9 && nodeType !== 11 ) {
return results;
}
// Try to shortcut find operations (as opposed to filters) in HTML documents
if ( !seed ) {
if ( ( context ? context.ownerDocument || context : preferredDoc ) !== document ) {
setDocument( context );
}
context = context || document;
if ( documentIsHTML ) {
// If the selector is sufficiently simple, try using a "get*By*" DOM method
// (excepting DocumentFragment context, where the methods don't exist)
if ( nodeType !== 11 && (match = rquickExpr.exec( selector )) ) {
// ID selector
if ( (m = match[1]) ) {
// Document context
if ( nodeType === 9 ) {
if ( (elem = context.getElementById( m )) ) {
// Support: IE, Opera, Webkit
// TODO: identify versions
// getElementById can match elements by name instead of ID
if ( elem.id === m ) {
results.push( elem );
return results;
}
} else {
return results;
}
// Element context
} else {
// Support: IE, Opera, Webkit
// TODO: identify versions
// getElementById can match elements by name instead of ID
if ( newContext && (elem = newContext.getElementById( m )) &&
contains( context, elem ) &&
elem.id === m ) {
results.push( elem );
return results;
}
}
// Type selector
} else if ( match[2] ) {
push.apply( results, context.getElementsByTagName( selector ) );
return results;
// Class selector
} else if ( (m = match[3]) && support.getElementsByClassName &&
context.getElementsByClassName ) {
push.apply( results, context.getElementsByClassName( m ) );
return results;
}
}
// Take advantage of querySelectorAll
if ( support.qsa &&
!compilerCache[ selector + " " ] &&
(!rbuggyQSA || !rbuggyQSA.test( selector )) ) {
if ( nodeType !== 1 ) {
newContext = context;
newSelector = selector;
// qSA looks outside Element context, which is not what we want
// Thanks to Andrew Dupont for this workaround technique
// Support: IE <=8
// Exclude object elements
} else if ( context.nodeName.toLowerCase() !== "object" ) {
// Capture the context ID, setting it first if necessary
if ( (nid = context.getAttribute( "id" )) ) {
nid = nid.replace( rcssescape, fcssescape );
} else {
context.setAttribute( "id", (nid = expando) );
}
// Prefix every selector in the list
groups = tokenize( selector );
i = groups.length;
while ( i-- ) {
groups[i] = "#" + nid + " " + toSelector( groups[i] );
}
newSelector = groups.join( "," );
// Expand context for sibling selectors
newContext = rsibling.test( selector ) && testContext( context.parentNode ) ||
context;
}
if ( newSelector ) {
try {
push.apply( results,
newContext.querySelectorAll( newSelector )
);
return results;
} catch ( qsaError ) {
} finally {
if ( nid === expando ) {
context.removeAttribute( "id" );
}
}
}
}
}
}
// All others
return select( selector.replace( rtrim, "$1" ), context, results, seed );
}
/**
* Create key-value caches of limited size
* @returns {function(string, object)} Returns the Object data after storing it on itself with
* property name the (space-suffixed) string and (if the cache is larger than Expr.cacheLength)
* deleting the oldest entry
*/
function createCache() {
var keys = [];
function cache( key, value ) {
// Use (key + " ") to avoid collision with native prototype properties (see Issue #157)
if ( keys.push( key + " " ) > Expr.cacheLength ) {
// Only keep the most recent entries
delete cache[ keys.shift() ];
}
return (cache[ key + " " ] = value);
}
return cache;
}
/**
* Mark a function for special use by Sizzle
* @param {Function} fn The function to mark
*/
function markFunction( fn ) {
fn[ expando ] = true;
return fn;
}
/**
* Support testing using an element
* @param {Function} fn Passed the created element and returns a boolean result
*/
function assert( fn ) {
var el = document.createElement("fieldset");
try {
return !!fn( el );
} catch (e) {
return false;
} finally {
// Remove from its parent by default
if ( el.parentNode ) {
el.parentNode.removeChild( el );
}
// release memory in IE
el = null;
}
}
/**
* Adds the same handler for all of the specified attrs
* @param {String} attrs Pipe-separated list of attributes
* @param {Function} handler The method that will be applied
*/
function addHandle( attrs, handler ) {
var arr = attrs.split("|"),
i = arr.length;
while ( i-- ) {
Expr.attrHandle[ arr[i] ] = handler;
}
}
/**
* Checks document order of two siblings
* @param {Element} a
* @param {Element} b
* @returns {Number} Returns less than 0 if a precedes b, greater than 0 if a follows b
*/
function siblingCheck( a, b ) {
var cur = b && a,
diff = cur && a.nodeType === 1 && b.nodeType === 1 &&
a.sourceIndex - b.sourceIndex;
// Use IE sourceIndex if available on both nodes
if ( diff ) {
return diff;
}
// Check if b follows a
if ( cur ) {
while ( (cur = cur.nextSibling) ) {
if ( cur === b ) {
return -1;
}
}
}
return a ? 1 : -1;
}
/**
* Returns a function to use in pseudos for input types
* @param {String} type
*/
function createInputPseudo( type ) {
return function( elem ) {
var name = elem.nodeName.toLowerCase();
return name === "input" && elem.type === type;
};
}
/**
* Returns a function to use in pseudos for buttons
* @param {String} type
*/
function createButtonPseudo( type ) {
return function( elem ) {
var name = elem.nodeName.toLowerCase();
return (name === "input" || name === "button") && elem.type === type;
};
}
/**
* Returns a function to use in pseudos for :enabled/:disabled
* @param {Boolean} disabled true for :disabled; false for :enabled
*/
function createDisabledPseudo( disabled ) {
// Known :disabled false positives: fieldset[disabled] > legend:nth-of-type(n+2) :can-disable
return function( elem ) {
// Only certain elements can match :enabled or :disabled
// https://html.spec.whatwg.org/multipage/scripting.html#selector-enabled
// https://html.spec.whatwg.org/multipage/scripting.html#selector-disabled
if ( "form" in elem ) {
// Check for inherited disabledness on relevant non-disabled elements:
// * listed form-associated elements in a disabled fieldset
// https://html.spec.whatwg.org/multipage/forms.html#category-listed
// https://html.spec.whatwg.org/multipage/forms.html#concept-fe-disabled
// * option elements in a disabled optgroup
// https://html.spec.whatwg.org/multipage/forms.html#concept-option-disabled
// All such elements have a "form" property.
if ( elem.parentNode && elem.disabled === false ) {
// Option elements defer to a parent optgroup if present
if ( "label" in elem ) {
if ( "label" in elem.parentNode ) {
return elem.parentNode.disabled === disabled;
} else {
return elem.disabled === disabled;
}
}
// Support: IE 6 - 11
// Use the isDisabled shortcut property to check for disabled fieldset ancestors
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