Javascript - 迭代元素的递归函数

Question

我刚刚开始阅读JavaScript,我正在尝试编写一个小的递归函数,它将搜索给定的节点并将值列表作为字符串返回.

我的HTML结构可能是这样的

<div id="parentfolder">parentfolder1
    <div class ="item1">item1</div>
    <div class ="item2">item2</div>
    <div id="parentfolder">parentfolder2
        <div class ="item1">item1</div>
        <div class ="item2">item2</div>
    </div>
</div>

这是我的Javascript函数:

function jsoncreator(parentfolderclass){
    var jstring = '';

    //get first occurance of parent folder
    var parentfolder = document.getElementById(parentfolderclass);
    var childnodes = parentfolder.childNodes;

    for (property in childnodes){
        jstring += property+ childnodes[property];
        if(childnodes[property] === parentfolderclass){
            jsoncreator(parentfolderclass);
            jstring += childnodes[property].value + '<br>';
        }
        else{
            //jstring += childnodes[i].value + '<br>';
        }
    }
    document.write(jstring);
}

所有我回来的都是

0[object Text]1[object HTMLDivElement]2[object Text]3[object HTMLDivElement]4[object Text]5[object HTMLDivElement]6[object Text]length7itemfunction item() { [native code] }

当我尝试打印childnodes值时,我得到一堆未定义的返回值.

如果有人能解释我做错了什么,我真的很感激.

Answer 1

您将需要执行以下操作(递归跨浏览器)

使用Javascript

function walkTheDOM(node, func) {
    func(node);
    node = node.firstChild;
    while (node) {
        walkTheDOM(node, func);
        node = node.nextSibling;
    }
}

function textNodeValuesToArray(node) {
    if (typeof node === "string") {
        node = document.getElementById(node);
    }

    var arrayOfText = [];

    function pushText(currentNode) {
        if (currentNode.nodeType === 3) {
            arrayOfText.push(currentNode.nodeValue);
        }
    }

    walkTheDOM(node, pushText);

    return arrayOfText;
}

console.log(textNodeValuesToArray("parentfolder"));

在jsfiddle

或使用 treewalker

浏览器兼容性

支持IE9 +,FF2 +,Chrome 1 +,Safari 3 +,Opera 9+

使用Javascript

function textNodeValuesToArray(node) {
    if (typeof node === "string") {
        node = document.getElementById(node);
    }

    var arrayOfText = [],
        treeWalker = document.createTreeWalker(node, NodeFilter.SHOW_TEXT, {
            acceptNode: function (node) {
                return NodeFilter.FILTER_ACCEPT;
            }
        }, false);

    while (treeWalker.nextNode()) {
        arrayOfText.push(treeWalker.currentNode.nodeValue);
    }

    return arrayOfText;
}

console.log(textNodeValuesToArray("parentfolder"));

在jsfiddle

没有递归和跨浏览器将是这样的

使用Javascript

避免使用标签

标签在JavaScript中并不常用,因为它们使程序更难以阅读和理解.尽可能避免使用标签,并根据具体情况,更喜欢调用函数或抛出错误.

function walkDOM(root, func) {
    var node = root;

    start: while (node) {
        func(node);
        if (node.firstChild) {
            node = node.firstChild;
            continue start;
        }

        while (node) {
            if (node === root) {
                break start;
            }

            if (node.nextSibling) {
                node = node.nextSibling;
                continue start;
            }

            node = node.parentNode;
        }
    }
}

function textNodeValuesToArray(node) {
    if (typeof node === "string") {
        node = document.getElementById(node);
    }

    var arrayOfText = [];

    function pushText(currentNode) {
        if (currentNode.nodeType === 3) {
            arrayOfText.push(currentNode.nodeValue);
        }
    }

    walkDOM(node, pushText);

    return arrayOfText;
}

console.log(textNodeValuesToArray("parentfolder"));

在jsfiddle