Question

I am trying to create a generic click event function for all the fields on a page which primarily checks for the target being blank or containing a user-entered value. However, I would like for this generic function to check for existence of a more specific function and, if one is found, to allow it to handle the validation of the target value.
example:

function genValueCheck(event) {
   var af = event.target.id+'_checkValue';
   if (typeof af == 'function') runFunction(af,[event]); // logic specific to this field
   else { 
      // logic for checking for blanks, etc which applies to all fields
   }
}

However, typeof returns ‘string’ in the above example, as it should since it is checking for the typeof ‘af’, and not what ‘af’ contains, i.e. the name of a function.

Is what I am attempting to do possible?

Thanks in advance.

Answer 1

That’s because af is a string. If your function exists in the global scope, use window[af]. This should work for you:

function genValueCheck(event) {
   var af = event.target.id+'_checkValue';
   if (typeof window[af] == 'function') runFunction(af,[event]); // logic specific to this field
   else { 
      // logic for checking for blanks, etc which applies to all fields
   }
}

Demo