jquery_parents

jquery1.0源码解读

jquery1.0 版本的 静态parents函数

jQuery.parents:

parents: function( elem ){
	var matched = [];
	var cur = elem.parentNode;
	while ( cur && cur != document ) {
		matched.push( cur );
		cur = cur.parentNode;
	}
	return matched;
},

通过jQuery.macros.axis来调用：

jQuery.macros:

jQuery.each( jQuery.macros.axis, function(i,n){
		jQuery.fn[ i ] = function(a) {
			var ret = jQuery.map(this,n);
			if ( a && a.constructor == String )
				ret = jQuery.filter(a,ret).r;
			return this.pushStack( ret, arguments );
		};
	});

###

jQuery.macros = {
	...省略部分代码
	axis: {

		parent: "a.parentNode",

		ancestors: jQuery.parents,

		parents: jQuery.parents,

		next: "jQuery.sibling(a).next",

		prev: "jQuery.sibling(a).prev",

		siblings: jQuery.sibling,

		children: "a.childNodes"
	}
	...省略部分代码
}

而在1.2.6版本中，我们可以看到做出的变化：

	jQuery.each({
	parent: function(elem){return elem.parentNode;},
	parents: function(elem){return jQuery.dir(elem,"parentNode");},
	next: function(elem){return jQuery.nth(elem,2,"nextSibling");},
	prev: function(elem){return jQuery.nth(elem,2,"previousSibling");},
	nextAll: function(elem){return jQuery.dir(elem,"nextSibling");},
	prevAll: function(elem){return jQuery.dir(elem,"previousSibling");},
	siblings: function(elem){return jQuery.sibling(elem.parentNode.firstChild,elem);},
	children: function(elem){return jQuery.sibling(elem.firstChild);},
	contents: function(elem){return jQuery.nodeName(elem,"iframe")?elem.contentDocument||elem.contentWindow.document:jQuery.makeArray(elem.childNodes);}
}, function(name, fn){
	jQuery.fn[ name ] = function( selector ) {
		var ret = jQuery.map( this, fn );

		if ( selector && typeof selector == "string" )
			ret = jQuery.multiFilter( selector, ret );

		return this.pushStack( jQuery.unique( ret ) );
	};
});

通过调用jQuery.dir静态函数:

jQuery.dir:

jQuery.dir(elem,"parentNode");

jQuery.dir函数如下，其实和1.0版本中的jQuery.parents大同小异:

dir: function( elem, dir ){
	var matched = [],
		cur = elem[dir];
	while ( cur && cur != document ) {
		if ( cur.nodeType == 1 )
			matched.push( cur );
		cur = cur[dir];
	}
	return matched;
}

下篇我们来分析为什么要做出这种改变？