get the text in a list item and modify it with javascript

I have a bunch of HTML list items and what i want is to be able to read the text of a list item and then be able to 开发者_开发知识库give the user the ability to modify it. the structure of each list item is the same:

<li id='1' class='attachment'>
    <a href='link.html'>TEXT VALUE I WANT TO READ AND MODIFY</a>
    <a href='link2.html'><img src'img1.jpg'></a>
    <a href='link3.html'><img src'img2.jpg'></a>
</li>

at the moment i am able to get the list item using

li = document.getElementById(id);

but if i get it to print out something like

li.childNodes[?] 
li.childNodes[?].data
li.childNodes[?].nodeValue etc...

i am never able to get it to print "TEXT VALUE I WANT TO READ AND MODIFY", it always gives null, undefined or [object Text] or something similar. any help would be greatly appreciated.

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You need to get the textContent or innerText properties:

var li = document.getElementById(id);
var t = "textContent" in li.childNodes[0] ? "textContent" : "innerText";
alert(li.childNodes[0][t]);

innerText is implemented by IE and textContent is implemented by standards compliant browsers.

Alternatively, if you're certain that the element's first child will be a text node, you can use

alert(li.childNodes[0].childNodes[0].nodeValue);

---

Based on your comment below, we can make a safe assumption that white-space is interfering with the childNodes property in your example. This is normal - childNodes returns both elements and text nodes that are direct descendants of the given element. The alternative is to use children in newer browsers:

// 1st example using `children` instead
var li = document.getElementById(id);
var t = "textContent" in li ? "textContent" : "innerText";
alert(li.children[0][t]);

// 2nd example using `children` instead
alert(li.children[0].childNodes[0].nodeValue);

children isn't supported pre Firefox 3.5 and in other older browsers. You could use li.getElementsByTagName("a") for the example that you've posted - but bear in mind that it will return all <a> element descendants, not just immediate children.

---

What about this:

var li = document.getElementById(1);
var a = li.getElementsByTagName('a');

alert(a[0].innerHTML);

And before anyone can suggest to just use jQuery, here's the equivalent:

$('li#someid a').html();

In my opinion, if you're doing fine without jQuery, don't use it.