How to call a JavaScript function from a string value?

Question

In a form I have a hidden field:

<input type="hidden" id="callback_function" value="myFunction" />

Now some JavaScript:

<script>
    $('.dataRow').click(function(){
        if($('#callback_function').val()){
            //same as executing myFunction();
            eval($('#callback_function').val()+'();');
        }
    });
</script>

This works but seems very inelegant. Is there a way to do this without using eval?

Why can't you just put `myFunction` in the code, instead of using a hidden input? — Bergi, Aug 07 '14 at 02:39
because the function (in this case 'myFunction') is variable, and is not a part of the document fragment which gets loaded by Ajax. the function pre-exists the script I showed — Samuel Fullman, Aug 07 '14 at 02:47
@Colin - yes, that post you referenced covers this very well, thanks. — Samuel Fullman, Aug 07 '14 at 02:51

score 3 · Accepted Answer · answered Aug 07 '14 at 02:38

It seems that the function is global (a property of window) so we don't need to eval it at all:

<script>
$('.dataRow').click(function(){
   var fnName = $('#callback_function').val();
   if(fnName && window[fnName]) {
       window[fnName]();
   }
});
</script>

How to call a JavaScript function from a string value?

1 Answers1