【IT168 技术】在实现delegate方法中，有一个很重要的辅助函数叫closest，虽然现在它归类为遍历节点这个模块中。这个函数实现得非常复杂，洋洋洒洒近50行，完全不符合极限编程的规矩。
closest: function( selectors, context ) {
var ret = [], i, l, cur = this[0];
// Array
if ( jQuery.isArray( selectors ) ) {//这分支的过滤逻辑基本与下面的一致
var match, selector,
matches = {},
level = 1;
if ( cur && selectors.length ) {
for ( i = 0, l = selectors.length; i < l; i++ ) {
selector = selectors[i];
if ( !matches[ selector ] ) {
matches[ selector ] = POS.test( selector ) ?
jQuery( selector, context || this.context ) :
selector;
}
}
while ( cur && cur.ownerDocument && cur !== context ) {
for ( selector in matches ) {
match = matches[ selector ];//这里频繁创建新的jQuery对象与使用is这样复杂的方法,我不觉得其高效到哪里去
if ( match.jquery ? match.index( cur ) > -1 : jQuery( cur ).is( match ) ) {
ret.push({ selector: selector, elem: cur, level: level });
}
}
cur = cur.parentNode;
level++;
}
}
return ret;
}
// String
var pos = POS.test( selectors ) || typeof selectors !== "string" ?
var ret = [], i, l, cur = this[0];
// Array
if ( jQuery.isArray( selectors ) ) {//这分支的过滤逻辑基本与下面的一致
var match, selector,
matches = {},
level = 1;
if ( cur && selectors.length ) {
for ( i = 0, l = selectors.length; i < l; i++ ) {
selector = selectors[i];
if ( !matches[ selector ] ) {
matches[ selector ] = POS.test( selector ) ?
jQuery( selector, context || this.context ) :
selector;
}
}
while ( cur && cur.ownerDocument && cur !== context ) {
for ( selector in matches ) {
match = matches[ selector ];//这里频繁创建新的jQuery对象与使用is这样复杂的方法,我不觉得其高效到哪里去
if ( match.jquery ? match.index( cur ) > -1 : jQuery( cur ).is( match ) ) {
ret.push({ selector: selector, elem: cur, level: level });
}
}
cur = cur.parentNode;
level++;
}
}
return ret;
}
// String
var pos = POS.test( selectors ) || typeof selectors !== "string" ?
