Is it the last `script` element the currently running script?

Solution 1:

It's not an absolute guarantee no. Check out this JSFiddle: http://jsfiddle.net/jAsek/

<!DOCTYPE html>
<title>Test case</title>
<div>
    <p>At the start</p>
    <script id="first">
        var scr1 = document.createElement("script");
        scr1.setAttribute("id", "early");
        document.body.appendChild(scr1);
    </script>
    <p>After the first script</p>
    <script id="second">
        function getCurrentScriptElement() {
            var scripts = document.getElementsByTagName('script');
            return scripts[scripts.length - 1];
        }

        alert(getCurrentScriptElement().id);
    </script>
    <p>At the end</p>
</div>

Here the alert reports the id of the injected script "early", not the id of currently running script "second".

There's no practical difference between internal and external scripts.

Solution 2:

I don’t think it’s a safe assumption at all, as browsers execute javascript code quite differently depending on a number of things (like if you have other script elements in the head, if they are external etc.).

You should just require people to use a dummy element with a custom id or class. That way you will also make it possible to do whatever you do multiple times a page without having to run the script multiple times.

This is also what is done when using widgets, for example Google’s +1 button.

An alternative would be to use document.write to write additional content while the script is executed. This will not replace the script tag however, but simply add something after it.

Is it the last `script` element the currently running script?

Solution 1:

Solution 2:

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