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sizzle分析记录: 自定义伪类选择器

可见性
  • :hidden
  • :visible

隐藏对象没有宽高,前提是用display:none处理的

jQuery.expr.filters.hidden = function( elem ) {    // Support: Opera <= 12.12    // Opera reports offsetWidths and offsetHeights less than zero on some elements    return elem.offsetWidth <= 0 && elem.offsetHeight <= 0;};jQuery.expr.filters.visible = function( elem ) {    return !jQuery.expr.filters.hidden( elem );};

 

内容
  • :contains(text)
  • :empty
  • :has(selector)
  • :parent

获取文本内容通过indexOf匹配

"contains": markFunction(function( text ) {    return function( elem ) {        return ( elem.textContent || elem.innerText || getText( elem ) ).indexOf( text ) > -1;    };}),

 

取空

递归这个节点,排除nodeType大于6的节点

// Contents"empty": function( elem ) {    // http://www.w3.org/TR/selectors/#empty-pseudo    // :empty is negated by element (1) or content nodes (text: 3; cdata: 4; entity ref: 5),    //   but not by others (comment: 8; processing instruction: 7; etc.)    // nodeType < 6 works because attributes (2) do not appear as children    for ( elem = elem.firstChild; elem; elem = elem.nextSibling ) {        if ( elem.nodeType < 6 ) {            return false;        }    }    return true;},

 

查看包含

递归sizzle通过传递上下文对象,实现包含查找

"has": markFunction(function( selector ) {    return function( elem ) {        return Sizzle( selector, elem ).length > 0;    };}),

 

匹配含有子元素或者文本的元素

"parent": function( elem ) {    return !Expr.pseudos["empty"]( elem );},