Executing [removed] elements inserted with [remove

Question

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>

Answer 1

Extending off of Larry's. I made it recursively search the entire block and children nodes.
The script now will also call external scripts that are specified with src parameter. Scripts are appended to the head instead of inserted and placed in the order they are found. So specifically order scripts are preserved. And each script is executed synchronously similar to how the browser handles the initial DOM loading. So if you have a script block that calls jQuery from a CDN and than the next script node uses jQuery... No prob! Oh and I tagged the appended scripts with a serialized id based off of what you set in the tag parameter so you can find what was added by this script.

exec_body_scripts: function(body_el, tag) {
    // Finds and executes scripts in a newly added element's body.
    // Needed since innerHTML does not run scripts.
    //
    // Argument body_el is an element in the dom.

    function nodeName(elem, name) {
        return elem.nodeName && elem.nodeName.toUpperCase() ===
              name.toUpperCase();
    };

    function evalScript(elem, id, callback) {
        var data = (elem.text || elem.textContent || elem.innerHTML || "" ),
            head = document.getElementsByTagName("head")[0] ||
                      document.documentElement;

        var script = document.createElement("script");
        script.type = "text/javascript";
        if (id != '') {
            script.setAttribute('id', id);
        }

        if (elem.src != '') {
            script.src = elem.src;
            head.appendChild(script);
            // Then bind the event to the callback function.
            // There are several events for cross browser compatibility.
            script.onreadystatechange = callback;
            script.onload = callback;
        } else {
            try {
                // doesn't work on ie...
                script.appendChild(document.createTextNode(data));      
            } catch(e) {
                // IE has funky script nodes
                script.text = data;
            }
            head.appendChild(script);
            callback();
        }
    };

    function walk_children(node) {
        var scripts = [],
          script,
          children_nodes = node.childNodes,
          child,
          i;

        if (children_nodes === undefined) return;

        for (i = 0; i<children_nodes.length; i++) {
            child = children_nodes[i];
            if (nodeName(child, "script" ) &&
                (!child.type || child.type.toLowerCase() === "text/javascript")) {
                scripts.push(child);
            } else {
                var new_scripts = walk_children(child);
                for(j=0; j<new_scripts.length; j++) {
                    scripts.push(new_scripts[j]);
                }
            }
        }

        return scripts;
    }

    var i = 0;
    function execute_script(i) {
        script = scripts[i];
        if (script.parentNode) {script.parentNode.removeChild(script);}
        evalScript(scripts[i], tag+"_"+i, function() {
            if (i < scripts.length-1) {
                execute_script(++i);
            }                
        });
    }

    // main section of function
    if (tag === undefined) tag = 'tmp';

    var scripts = walk_children(body_el);

    execute_script(i);
}

Answer 2

A solution without using "eval":

var setInnerHtml = function(elm, html) {
  elm.innerHTML = html;
  var scripts = elm.getElementsByTagName("script");
  // If we don't clone the results then "scripts"
  // will actually update live as we insert the new
  // tags, and we'll get caught in an endless loop
  var scriptsClone = [];
  for (var i = 0; i < scripts.length; i++) {
    scriptsClone.push(scripts[i]);
  }
  for (var i = 0; i < scriptsClone.length; i++) {
    var currentScript = scriptsClone[i];
    var s = document.createElement("script");
    // Copy all the attributes from the original script
    for (var j = 0; j < currentScript.attributes.length; j++) {
      var a = currentScript.attributes[j];
      s.setAttribute(a.name, a.value);
    }
    s.appendChild(document.createTextNode(currentScript.innerHTML));
    currentScript.parentNode.replaceChild(s, currentScript);
  }
}

This essentially clones the script tag and then replaces the blocked script tag with the newly generated one, thus allowing execution.

Answer 3

@phidah... Here is a very interesting solution to your problem: http://24ways.org/2005/have-your-dom-and-script-it-too

So it would look like this instead:

<img src="empty.gif" onload="alert('test');this.parentNode.removeChild(this);" />

Answer 4

You may take a look at this post. The code might look like this:

var actualDivToBeUpdated = document.getElementById('test');
var div = document.createElement('div');
div.innerHTML = '<script type="text/javascript">alert("test");<\/script>';
var children = div.childNodes;
actualDivToBeUpdated.innerHTML = '';
for(var i = 0; i < children.length; i++) {
    actualDivToBeUpdated.appendChild(children[i]);
}

Answer 5

Thanks to Larry's script, which worked perfectly well in IE10, this is what I've used:

$('#' + id)[0].innerHTML = result;
$('#' + id + " script").each(function() { this.text = this.text || $(this).text();} );

Answer 6

scriptNode.innerHTML = code didn't work for IE. The only thing to do is replace with scriptNode.text = code and it work fine