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  • sizzle分析记录: 自定义伪类选择器

    可见性

    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

    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 );
    },
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  • 原文地址:https://www.cnblogs.com/aaronjs/p/3859884.html
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