前文提要，jQuery用init方法创建的，它是jQuery.fn.init的实例而非jQuery的实例，后期会用jQuery.fn.init.
prototype = jQuery.fn; 把相应的能力从jQuery.prototype搬运到jQuery.fn.init.prototype上。因此，init之后，作者就放心地往 jQuery的原型添加方法。而这些原型更多的时候是往外调用其静态方法来工作。一开始，都是一些用于构建类数组的东西。像 setArray,makeArray,size,get,pushStack等方法。
//另一个复杂的方法
css: function( key, value ) {
// ignore negative width and height values
if ( (key == 'width' || key == 'height') && parseFloat(value) < 0 )
value = undefined;
return this.attr( key, value, "curCSS" );
},
//与css与attr一样，既能读亦能写
text: function( text ) {
if ( typeof text !== "object" && text != null )
return this.empty().append( (this[0] && this[0].ownerDocument || document).createTextNode( text ) );
var ret = "";
jQuery.each( text || this, function(){
jQuery.each( this.childNodes, function(){
if ( this.nodeType != 8 )
ret += this.nodeType != 1 ?
this.nodeValue :
jQuery.fn.text( [ this ] );
});
});
return ret;
},
//把匹配的元素作出了为一个整体用参数里的标签（如果传入的是元素也会转换为标签）包起来,
//$("p").wrapAll('<div></div>') => <div><p>******</p><p>******</p><p>******</p></div>
//这东西应该叫wrapOutter更好
wrapAll: function( html ) {
if ( this[0] ) {
// The elements to wrap the target around
var wrap = jQuery( html, this[0].ownerDocument ).clone();
if ( this[0].parentNode )
wrap.insertBefore( this[0] );
wrap.map(function(){
var elem = this;
while ( elem.firstChild )
elem = elem.firstChild;
return elem;
}).append(this);
}
return this;
},
//相当于把匹配的元素取得其innerHTML，然后用wrapAll方法包起来
//$("p").wrapInner('<div></div>') => <p><div>******</div></p><p><div>******</div></p><p><div>******</div></p>
wrapInner: function( html ) {
return this.each(function(){
jQuery( this ).contents().wrapAll( html );
});
},
//与上面相反，有点像outterHTML，内容外面加一层皮
//$("p").wrap('<div></div>') => <div><p>******</p></div><div><p>******</p></div><div><p>******</p></div>
wrap: function( html ) {
return this.each(function(){
jQuery( this ).wrapAll( html );
});
},
接着下来分析append，prepend，before，after。内部实现非常复杂，先扼要类比一下已有的API吧。
//append:向每个匹配的元素内部追加内容。
//相当于
//insertAdjacentHTML("beforeEnd",htmlstr)
//insertAdjacentElement("beforeEnd",dom)
//insertAdjacentElement("beforeEnd",jQueryEl)
//并且具有处理复数个DOM对象的能力（内部用jQuery.each实现）
//prepend:向每个匹配的元素内部前置内容。
//相当于
//insertAdjacentHTML("afterBegin",htmlstr)
//insertAdjacentElement("afterBegin",dom)
//insertAdjacentElement("afterBegin",jQueryEl)
//并且具有处理复数个DOM对象的能力（内部用jQuery.each实现）
//before:在每个匹配的元素之前插入内容。
//相当于
//insertAdjacentHTML("beforeBegin",htmlstr)
//insertAdjacentElement("beforeBegin",dom)
//insertAdjacentElement("beforeBegin",jQueryEl)
//并且具有处理复数个DOM对象的能力（内部用jQuery.each实现）
//after:在每个匹配的元素之后插入内容。。
//相当于
//insertAdjacentHTML("afterEnd",htmlstr)
//insertAdjacentElement("afterEnd",dom)
//insertAdjacentElement("afterEnd",jQueryEl)
//并且具有处理复数个DOM对象的能力（内部用jQuery.each实现）
这些方法内部都调用一个叫domManip的方法，它的存在价值仅仅是为了兼容邪恶的火狐，因为火狐死活不支持IE的insertAdjacentXXX系列。
//主要用于返回上次覆盖了DOM元素数组
end: function() {
return this.prevObject || jQuery( [] );
},
// For internal use only.
// Behaves like an Array's method, not like a jQuery method.
push: [].push,
sort: [].sort,
splice: [].splice,
//jQuery强大的CSS选择器
find: function( selector ) {
if ( this.length === 1 ) {
var ret = this.pushStack( [], "find", selector );
ret.length = 0;
//分别为表达式，上下文，与之前获得的元素集合（它们将作为此次的搜索起点）
jQuery.find( selector, this[0], ret );
return ret;
} else {
//每次都会重新洗牌，因此必须进行压栈操作
return this.pushStack( jQuery.unique(jQuery.map(this, function(elem){
return jQuery.find( selector, elem );
})), "find", selector );
}
},
//先复制DOM再复制其上的事件
clone: function( events ) {
// Do the clone
var ret = this.map(function(){
if ( !jQuery.support.noCloneEvent && !jQuery.isXMLDoc(this) ) {
// IE copies events bound via attachEvent when
// using cloneNode. Calling detachEvent on the
// clone will also remove the events from the orignal
// In order to get around this, we use innerHTML.
// Unfortunately, this means some modifications to
// attributes in IE that are actually only stored
// as properties will not be copied (such as the
// the name attribute on an input).
var html = this.outerHTML;
if ( !html ) {
var div = this.ownerDocument.createElement("div");
div.appendChild( this.cloneNode(true) );
html = div.innerHTML;
}
//将字符串转换成jQuery对象
return jQuery.clean([html.replace(/ jQuery\d+="(?:\d+|null)"/g, "").replace(/^\s*/, "")])[0];
} else
return this.cloneNode(true);
});
//许多是后面的方法，到时再说
// Copy the events from the original to the clone
if ( events === true ) {
var orig = this.find("*").andSelf(), i = 0;
ret.find("*").andSelf().each(function(){
if ( this.nodeName !== orig[i].nodeName )
return;
var events = jQuery.data( orig[i], "events" );
for ( var type in events ) {
for ( var handler in events[ type ] ) {
jQuery.event.add( this, type, events[ type ][ handler ], events[ type ][ handler ].data );
}
}
i++;
});
}
// Return the cloned set
return ret;
},
//如果参数是函数则用jQuery.greg，否则用jQuery.multiFiler
filter: function( selector ) {
return this.pushStack(
jQuery.isFunction( selector ) &&
jQuery.grep(this, function(elem, i){
return selector.call( elem, i );
}) ||
jQuery.multiFilter( selector, jQuery.grep(this, function(elem){
return elem.nodeType === 1;
}) ), "filter", selector );
},
//筛选最近的元素
closest: function( selector ) {
//判断是否用于方位的
var pos = jQuery.expr.match.POS.test( selector ) ? jQuery(selector) : null,
closer = 0;
//把得到元素用map进行进一步的筛选
return this.map(function(){
var cur = this;
while ( cur && cur.ownerDocument ) {
if ( pos ? pos.index(cur) > -1 : jQuery(cur).is(selector) ) {
jQuery.data(cur, "closest", closer);
return cur;
}
cur = cur.parentNode;
closer++;
}
});
},
//用于反选，内部调用filter
not: function( selector ) {
if ( typeof selector === "string" )
// test special case where just one selector is passed in
if ( isSimple.test( selector ) )//如果单一的类
return this.pushStack( jQuery.multiFilter( selector, this, true ), "not", selector );
else
selector = jQuery.multiFilter( selector, this );
//处理NodeList
var isArrayLike = selector.length && selector[selector.length - 1] !== undefined && !selector.nodeType;
return this.filter(function() {//再回调用filter
return isArrayLike ? jQuery.inArray( this, selector ) < 0 : this != selector;
});
},
//添加新元素，内部进行清零压栈等操作
add: function( selector ) {
return this.pushStack( jQuery.unique( jQuery.merge(
this.get(),
typeof selector === "string" ?
jQuery( selector ) :
jQuery.makeArray( selector )
)));
},
//相当于javascript1.6 Array的some方法
is: function( selector ) {
return !!selector && jQuery.multiFilter( selector, this ).length > 0;
},
//怎么这方法那么笨重？！
hasClass: function( selector ) {
return !!selector && this.is( "." + selector );
},
//基本上是用于获取元素value属性的值
//对于下拉开框，则是其innerText
//与css,attr一样，可读可写
val: function( value ) {
if ( value === undefined ) {
var elem = this[0];
if ( elem ) {
if( jQuery.nodeName( elem, 'option' ) )
return (elem.attributes.value || {}).specified ? elem.value : elem.text;
// We need to handle select boxes special
if ( jQuery.nodeName( elem, "select" ) ) {
var index = elem.selectedIndex,
values = [],
options = elem.options,
one = elem.type == "select-one";
// Nothing was selected
if ( index < 0 )
return null;
// Loop through all the selected options
for ( var i = one ? index : 0, max = one ? index + 1 : options.length; i < max; i++ ) {
var option = options[ i ];
if ( option.selected ) {
// Get the specifc value for the option
value = jQuery(option).val();
// We don't need an array for one selects
if ( one )
return value;
// Multi-Selects return an array
values.push( value );
}
}
return values;
}
// Everything else, we just grab the value
return (elem.value || "").replace(/\r/g, "");
}
return undefined;
}
if ( typeof value === "number" )
value += '';
return this.each(function(){
if ( this.nodeType != 1 )
return;
//处理radio的checkbox checked属性，用于返回true与false
if ( jQuery.isArray(value) && /radio|checkbox/.test( this.type ) )
this.checked = (jQuery.inArray(this.value, value) >= 0 ||
jQuery.inArray(this.name, value) >= 0);
else if ( jQuery.nodeName( this, "select" ) ) {
var values = jQuery.makeArray(value);
jQuery( "option", this ).each(function(){
this.selected = (jQuery.inArray( this.value, values ) >= 0 ||
jQuery.inArray( this.text, values ) >= 0);
});
if ( !values.length )
this.selectedIndex = -1;
} else
this.value = value;
});
},
//就是innerHTML
html: function( value ) {
return value === undefined ?
(this[0] ?
this[0].innerHTML.replace(/ jQuery\d+="(?:\d+|null)"/g, "") :
null) :
this.empty().append( value );
},
//与replaceNode差不多
replaceWith: function( value ) {
return this.after( value ).remove();
},
//把等于此索引值的DOM对象从jQuery对象中取出
eq: function( i ) {
return this.slice( i, +i + 1 );
},
