Dynamically change a div's ID?
I have a bunch of divs with weird id and each of them contains a video. They're actually video embed codes but they're not usual to me. Here's one example:
<div id="evp-1fae4e37639894816f03591bc7009c68-wrap" class="evp-video-wrap"></div><script type="text/javascript" src="http://domain.com/evp/framework.php?div_id=evp-1fae4e37639894816f03591bc7009c68&id=cmVsYXRpb25zaGlwLW1hcmtldGluZy0xLmZsdg%3D%3D&v=1278525356"></script><script type="text/javascript">_evpInit('cmVsYXRpb25zaGlwLW1hcmtldGluZy0xLmZsdg==');</script>
What I want to do is create a video playlist. As a part of that, I created list using divs also which use the onclick attribute to trigger my JS function to switch between videos. Here's how it looks:
<div class="vid-list" onclick="switchvideo('http://domain.com/html-vids/headline-vids/second-vid.html', 2)"><p>This a video tutorial for blah blah blah.</p></div>
The problem is, each time I switch to another video the div id of the embed code changes also because otherwise it won't work. So I need to change that before loading the video script inside the div. I tried to ac开发者_如何学JAVAhieve that using the following JS function:
function switchvideo(url, vidnumber)
{
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
xmlhttp.open("GET",url,false);
xmlhttp.send(null);
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
xmlhttp.open("GET",url,false);
xmlhttp.send();
}
var div_node = document.getElementByClass('evp-video-wrap');
if ( vidnumber == 2 ) {
div_node.id = 'evp-78c0b7c4f6d3377954825f145734fd5c-wrap';
}
document.getElementById(div_node.id).innerHTML=xmlhttp.responseText;
}
Apparently it's not working. I suspect the problem are the lines in bold above. I tried to get the element by 'class' and its id by using 'div_node.id'. I am assuming that by doing 'document.getElementByClass', I am getting the reference to that element so I could use it to manipulate its other attributes. But I am not sure... Could anyone pls enlighten me??
There is no getElementByClass()
method. There is a getElementByClassName()
but it's not available in every browser.
Here is one you can use:
// http://www.dustindiaz.com/getelementsbyclass/
function getElementsByClass(searchClass, node, tag) {
var classElements = new Array();
if (node == null) node = document;
if (tag == null) tag = '*';
var els = node.getElementsByTagName(tag);
var elsLen = els.length;
var pattern = new RegExp("(^|\\s)" + searchClass + "(\\s|$)");
for (i = 0, j = 0; i < elsLen; i++) {
if (pattern.test(els[i].className)) {
classElements[j] = els[i];
j++;
}
}
return classElements;
}
Then you can call it as
getElementByClass('evp-video-wrap');
Your ajax is a bit tricky, but here is a more general one:
function getXmlHttpObject() {
var xmlHttp;
try {
// Firefox, Opera 8.0+, Safari
xmlHttp = new XMLHttpRequest();
} catch (e) {
// Internet Explorer
try {
xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
}
if (!xmlHttp) {
alert("Your browser does not support AJAX!");
}
return xmlHttp;
}
function ajax(url, onSuccess, onError) {
var xmlHttp = getXmlHttpObject();
xmlHttp.onreadystatechange = function() {
if (this.readyState === 4) {
// onSuccess
if (this.status === 200 && typeof onSuccess == 'function') {
onSuccess(this.responseText);
}
// onError
else if(typeof onError == 'function') {
onError();
}
}
};
xmlHttp.open("GET", url, true);
xmlHttp.send(null);
return xmlHttp;
}
Finally your code becomes:
function switchvideo(url, vidnumber) {
var div_node = getElementByClass('evp-video-wrap')[0];
// make a call to the url, and execute the
// callback when the response is available
ajax(url, function( responseText ){
if (vidnumber == 2) {
div_node.id = 'evp-78c0b7c4f6d3377954825f145734fd5c-wrap';
}
document.getElementById(div_node.id).innerHTML = responseText;
});
}
You can see the whole code [here]
getElementByClass isn't a standard method. Is it possible for you to use a framework for this? jQuery has a nice mechanism to search for an element by class, as do the other frameworks. It also makes it much easier to do the AJAX bits in a cross-browser supported way.
function switchvideo(url, vidnumber)
{
$.get(url, function(data) {
var div_node = $('.evp-video-wrap');
if (vidnumber == 2) {
div_node.attr('id', 'evp-78c0b7c4f6d3377954825f145734fd5c-wrap');
}
div_node.html( data );
});
}
An alternative would be to write your own getElementByClass or specific code to search for a DIV by class. Note: I assume you're only interested in the first match.
function getDivByClass( klass )
{
var regex = new RegExp( '(^|\\s+)' + klass + '(\\s+|$)' );
for (div in document.getElementsByTagName('div')) {
if (regex.text( div.className)) {
return div;
}
}
return null;
}
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