Create a variable name with another variables contents

Question

Each time a field that has the class of 'required' is changed I want to set a timeout. My original script had a bug where if you move onto another field with the same class before the timeout is complete it resets it and only carrys out the function on the last field. To combat this, I want to add the name of the specific field to the timer function. However my attempt below doesn't work. I am thinking if there is a timer for each field it should work. Firstly, is my method correct? and if so what am I doing wrong? If not, how can I achieve my goal?

$('.required', this).bind('keyup change',function() {
 var fieldName = $(this).attr('name');
 var timer[fieldName] = null;
 clearTimeout(timer[fieldName]);
 timer[fieldName] = setTimeout(
 function() {
 if( !$(this).val() ) {
 $(this).nextAll('.required-prompt').first().remove();
 $(this).after(prompt);
 } else {
 $(this).nextAll('.required-prompt').first().remove();
 required = true;
 } 
 }
 , 2000
 );
});

• A. Wolff: isn't timer undefined here or you are declaring it somewhere else?!
• user1932079: @A.Wolff timer is defined on line 3 above, so it's scope is in the function.
• A. Wolff: @JeremyMiller No, it is not! BTW, this is not valid syntax, using var
• user1932079: @A.Wolff Spot on! Good catch... can't believe I didn't see that!

Answer 1

Code should be like this:

var timer = {};
$('.required', this).bind('keyup change',function() {
 var fieldName = $(this).attr('name');
 clearTimeout(timer[fieldName]);
 timer[fieldName] = setTimeout(
 function() {
 if( !$(this).val() ) {
 $(this).nextAll('.required-prompt').first().remove();
 $(this).after(prompt);
 } else {
 $(this).nextAll('.required-prompt').first().remove();
 required = true;
 } 
 }
 , 2000
 );
});

• user2889310: Hi. Thank you. I have tried this, but its giving an error of 'TypeError: f.nodeName is undefined' in the jquery library. Any ideas?
• A. Wolff: Your FIELD as a name attribute? What about providing relevant HTML code and a jsfiddle?!
• user2889310: Fixed it myself. Thank you.