xpath 获取 frameset 内的元素

xpath.js

function getElementsByXpath(xpath,document) {
    var nodes = [];
    var iterator = document.evaluate(xpath, document, null, XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null );

    try {
        var thisNode = iterator.iterateNext();

        while (thisNode) {
            nodes.push(thisNode);
            thisNode = iterator.iterateNext();
        }
    }
    catch (e) {
        console.log( 'Error: Document tree modified during iteration ' + e );
    }
    console.log(nodes);
    return nodes;
}
var doc2 = getElementsByXpath("//frameset/frame[1]",document)[0].contentDocument;
var list = getElementsByXpath("//a",doc2);
var urls = "";
for(var i = 0 ;i < list.length;i++) {
    var a = list[i];
    urls += a.href;
    urls += "\n";

}
console.log(urls);