Javascript/XML - 获取节点名称

Javascript/XML - Getting the node name

提问by bogatyrjov

I need to get the the name of the tag "myChild" and the "content". This is simple, but i am stuck, sleepy and here is what I get with my tests:

我需要获取标签“myChild”和“内容”的名称。这很简单，但我被困住了，困了，这是我的测试结果：

XML:

XML：

...
<myParent>
  <myChild>content</myChild>
</myParent>
<myParent>
  <myChild>content</myChild>
</myParent>
...

JS:

JS：

var x=xmlDoc.getElementsByTagName("myParent");
alert(x[1].childNodes[0].nodeName); //returns "#text" - "myChild" needed
alert(x[1].childNodes[0].nodeValue); //returns "" - "content" needed

回答by T.J. Crowder

You want tagName, which is the name of the element.(Sorry about that, for Elements, tagNameand nodeNameare the same.)

您想要tagName，这是元素的名称。（很抱歉，对于Elements，tagName和nodeName是一样的。）

The problem is that the first child of your myParentelement isn't the myChildelement, it's a text node (containing whitespace). Your structure looks like this:

问题是myParent元素的第一个子元素不是myChild元素，而是一个文本节点（包含空格）。您的结构如下所示：

• Element "myParent"
  • Text node with a carriage return and some spaces or tabs
  • Element "myChild"
    • Text node with "content"
  • Text node with a carriage return and some spaces or tabs
• Element "myParent"
  • Text node with a carriage return and some spaces or tabs
  • Element "myChild"
    • Text node with "content"
  • Text node with a carriage return and some spaces or tabs

• 元素“我的父母”
  • 带有回车符和一些空格或制表符的文本节点
  • 元素“我的孩子”
    • 带有“内容”的文本节点
  • 带有回车符和一些空格或制表符的文本节点
• 元素“我的父母”
  • 带有回车符和一些空格或制表符的文本节点
  • 元素“我的孩子”
    • 带有“内容”的文本节点
  • 带有回车符和一些空格或制表符的文本节点

You need to navigate down to the actual myChildelement, which you can do with getElementsByTagNameagain, or just by scanning:

您需要向下导航到实际myChild元素，您可以getElementsByTagName再次使用它，或者只需扫描：

var x=xmlDoc.getElementsByTagName("myParent");
var c = x[1].firstChild;
while (c && c.nodeType != 1) { // 1 = ELEMENT_NODE
    c = c.nextSibling;
}
alert(c.nodeName); // "myChild"

Note that Elements don't have a meaningful nodeValueproperty; instead, you collect their child text nodes. (More in the DOM specs: DOM2, DOM3.)

请注意，Elements 没有有意义的nodeValue属性；相反，您收集它们的子文本节点。（更多在 DOM 规范中：DOM2，DOM3。）

Also note that when indexing into a NodeList, the indexes start at 0. You seem to have started with 1; ignore this comment if you were skipping the first one for a reason.

另请注意，索引到 a 时NodeList，索引从0. 你似乎已经开始了1; 如果您出于某种原因跳过第一个评论，请忽略此评论。

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Off-topic: It's always best to understand the underlying mechanics of what you're working with, and I do recommend playing around with the straight DOM and referring to the DOM specs listed above. But for interacting with these trees, a good library can be really useful and save you a lot of time. jQueryworks well with XML data. I haven't used any of the others like Prototype, YUI, Closure, or any of several otherswith XML, so can't speak to that, but I expect at least some of them support it.

题外话：理解你所使用的底层机制总是最好的，我建议你使用直接的 DOM 并参考上面列出的 DOM 规范。但是对于与这些树进行交互，一个好的库会非常有用并为您节省大量时间。jQuery可以很好地处理 XML 数据。我没有使用过任何其他的，比如Prototype，YUI，Closure，或者其他几个XML 中的任何一个，所以不能说，但我希望至少其中一些支持它。

回答by Dr.Molle

Try x[1].getElementsByTagName('*')[0]instead.

试试吧x[1].getElementsByTagName('*')[0]。

(This is only trustable for index 0, other indexes may return elements that are not child-nodes, if the direct childs contain further element-nodes. )

（这仅对索引 0 可信，如果直接子节点包含更多元素节点，则其他索引可能返回不是子节点的元素。）