Question

Why is that when i give alert inside the jquery block it runs other wise it doesn’t show any output?

  <script type="text/javascript">
(function map() {
var test = document.createElement('script'); 
    test.type = 'text/javascript'; 
    test.async = true;
test.src = 'myjsfile.js';
var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(test, s);
});
  </script>

I am trying to create a plugin and the script calls the myjsfile.js and will execute the functions inside it only is if i add alert() inside the above code.

Answer 1

If the code that you show is the first script tag on the document, I could see this maybe causing a problem:

var s = document.getElementsByTagName('script')[0];
s.parentNode.insertBefore(test, s);

Why not append it directly to the head or body? More straightforward, in my opinion.

(document.getElementsByTagName('head')[0]
 || document.getElementsByTagName('body')[0]).appendChild(test);

Also, you may not be getting any output because you aren’t actually calling your function. Try this:

<script type="text/javascript">
    (function map() {
        // Your code here
    })(); // Add () to call your function

    // Or, just call it the old fashioned way when you're done.
    map();
</script>

One other thing to watch out for, map is already a function within jQuery, so be cautious with your name spaces and how you try to call your function.