javascript - Javascript获取节点的XPath(Javascript get XPath of a node)

Question

无论如何，有没有在Javascript中返回DOM元素的XPath字符串？

  ask by Louis translate from so

Answer 1

I refactored this from another example.

(我从另一个示例重构了这一点。)

It will attempt to check or there is for sure a unique id and if so use that case to shorten the expression.

(它将尝试检查或确定存在唯一的ID，如果是，则使用这种情况来缩短表达式。)

function createXPathFromElement(elm) { 
    var allNodes = document.getElementsByTagName('*'); 
    for (var segs = []; elm && elm.nodeType == 1; elm = elm.parentNode) 
    { 
        if (elm.hasAttribute('id')) { 
                var uniqueIdCount = 0; 
                for (var n=0;n < allNodes.length;n++) { 
                    if (allNodes[n].hasAttribute('id') && allNodes[n].id == elm.id) uniqueIdCount++; 
                    if (uniqueIdCount > 1) break; 
                }; 
                if ( uniqueIdCount == 1) { 
                    segs.unshift('id("' + elm.getAttribute('id') + '")'); 
                    return segs.join('/'); 
                } else { 
                    segs.unshift(elm.localName.toLowerCase() + '[@id="' + elm.getAttribute('id') + '"]'); 
                } 
        } else if (elm.hasAttribute('class')) { 
            segs.unshift(elm.localName.toLowerCase() + '[@class="' + elm.getAttribute('class') + '"]'); 
        } else { 
            for (i = 1, sib = elm.previousSibling; sib; sib = sib.previousSibling) { 
                if (sib.localName == elm.localName)  i++; }; 
                segs.unshift(elm.localName.toLowerCase() + '[' + i + ']'); 
        }; 
    }; 
    return segs.length ? '/' + segs.join('/') : null; 
}; 

function lookupElementByXPath(path) { 
    var evaluator = new XPathEvaluator(); 
    var result = evaluator.evaluate(path, document.documentElement, null,XPathResult.FIRST_ORDERED_NODE_TYPE, null); 
    return  result.singleNodeValue; 
}