John Davidson

javascript - Executing <script> elements inserted with .innerHTML

0 comments
Message:


I've got a script that inserts some content into an element using innerHTML.



The content could for example be:



<script type="text/javascript">alert('test');</script>
<strong>test</strong>


Problem is that the code inside the <script> tag doesn't get executed.
I googled it a bit but there were no apparent solutions. If I inserted the content using jQuery $(element).append(content);the script parts got eval'd before being injected into the DOM.



Has anyone got a snippet of code that executes all the <script> elements? The jQuery code was a bit complex so I couldn't really figure out how it was done.



Edit:



By peeking into the jQuery code I've managed to figure out how jQuery does it, which resulted in the following code:



Demo:
<div id="element"></div>

<script type="text/javascript">
function insertAndExecute(id, text)
{
domelement = document.getElementById(id);
domelement.innerHTML = text;
var scripts = [];

ret = domelement.childNodes;
for ( var i = 0; ret[i]; i++ ) {
if ( scripts && nodeName( ret[i], "script" ) && (!ret[i].type || ret[i].type.toLowerCase() === "text/javascript") ) {
scripts.push( ret[i].parentNode ? ret[i].parentNode.removeChild( ret[i] ) : ret[i] );
}
}

for(script in scripts)
{
evalScript(scripts[script]);
}
}
function nodeName( elem, name ) {
return elem.nodeName && elem.nodeName.toUpperCase() === name.toUpperCase();
}
function evalScript( elem ) {
data = ( elem.text || elem.textContent || elem.innerHTML || "" );

var head = document.getElementsByTagName("head")[0] || document.documentElement,
script = document.createElement("script");
script.type = "text/javascript";
script.appendChild( document.createTextNode( data ) );
head.insertBefore( script, head.firstChild );
head.removeChild( script );

if ( elem.parentNode ) {
elem.parentNode.removeChild( elem );
}
}

insertAndExecute("element", "<scri"+"pt type='text/javascript'>document.write('This text should appear as well.')</scr"+"ipt><strong>this text should also be inserted.</strong>");
</script>


My Answer:
JavaScript code can be executed in a few different ways:

1. In a web browser: JavaScript code can be embedded directly into HTML files using `