Question

I am coding to make simple validator for form.

In order to validate form dynamically, I’ve planned to use eval function.

As you see in the javascript coding, var funcCall becomes a name of function with a parameter of jquery selected dom.

But that makes error. (Uncaught SyntaxError: Unexpected identifier)

What I’d like to know is that should I only use String in eval() or is there a better way to do this?

---

var Submit = {
    validateFilters : ["Submit.emptyCheckFilter"], // This is validator filters
    emptyCheckFilter : function(element) 
        //this is filter to validate if it's empty or not.
        console.log("this has been called");
    },
    doValidate : function(form) {
        var children = $(form).children();
        var filters = Submit.validateFilters;

        $.each(children, function(key, value) { // Loop over form element

            for(var i = 0; i < filters.length; i++) {
                //Here's error comes the value is not String. it's selected item by jQuery.
                //Uncaught SyntaxError: Unexpected identifier <= This occurs.
                var funcCall = filters[i] + "(" + value + ");";

                // Call the filter
                eval(funcCall);
            }

            return false; 
        });
    },
   ...
}

Answer 1

You should not use eval for this. It is much simpler and cleaner to just use function instances directly instead of their “names”.

var Submit = {
    validateFilters : [function(element) {
        //this is filter to validate if it's empty or not.
        console.log("this has been called");
    }], // This is validator filters
    doValidate : function(form) {
        var children = $(form).children();
        var filters = Submit.validateFilters;

        $.each(children, function(key, value) { // Loop over form element

            for(var i = 0; i < filters.length; i++) {
                filters[i](value);
            }

            return false; 
        });
    },
   ...
}