javascript - jquery validate plugin on dynamic form inputs not working

Question

I've a form where I'm having some fields and then if needed user can add more fields of same type. Im using http://jqueryvalidation.org/ validate plugin to validate fields.

As I read somewhere jquery validate plugin requires unique names to fields for validating them. So i'm naming each field uniquely. First I hoped that validate plugin will take care of dynamically added element's validation if I add rules using classes. But it turns out it does not.

So even if name of each field is unique, validate plugin validates only first input which was rendered initially.

I even tried using $.clone() in hope that it'll take care of all event bindings. But it did not worked for me. So I moved to underscore to repeat the markup as there are number of fields and I don't want to write templates in JS and name accordingly.

I can't find a solution to this and stuck here. Can't more on until this issue is resolved.

Here's JS that I've written.

$("#work_form").validate();

$(".work_emp_name").rules("add", {
    required: true
});

_.templateSettings.variable = "element";
var tpl = _.template($("#form_tpl").html());

var counter = 1;

$("form").on("click", ".add_employer", function (e) {
    e.preventDefault();
    var tplData = {
        i: counter
    };
    $("#word_exp_area").append(tpl(tplData));
    counter += 1;
});

Please find markup in fiddle set up.

example and code set up here

Answer 1

When using one of the methods from this plugin, like .rules(), and targeting more than one element, like a class, you must also use the jQuery .each() method.

$('.work_emp_name').each(function () {
    $(this).rules("add", {
        required: true
    });
});

And you cannot use .rules() on elements that don't yet exist in the DOM. Simply move the .rules() method to inside the function that creates your new inputs.

$("form").on("click", ".add_employer", function (e) {
    e.preventDefault();
    var tplData = {
        i: counter
    };
    $("#word_exp_area").append(tpl(tplData));
    counter += 1;
    $('.work_emp_name').each(function () { 
        $(this).rules("add", {
            required: true
        });
    });
});

Working DEMO: http://jsfiddle.net/Yy2gB/10/

---

However, you can make it more efficient by only targeting the one new field, instead of all fields with the work_emp_name class.

$("form").on("click", ".add_employer", function (e) {
    e.preventDefault();
    var tplData = {
        i: counter
    };
    $("#word_exp_area").append(tpl(tplData));   // <- add new field
    $('input[name="work_emp_name['+counter+']"]').rules("add", {  // <- apply rule to new field
        required: true
    });
    counter += 1;
});

Working DEMO: http://jsfiddle.net/Yy2gB/11/

---

Both of my examples above are for adding rules to the dynamically created fields. You'll still need to declare any rules for your static fields upon dom ready as follows...

$("#work_form").validate({
    rules: {
        "work_emp_name[0]": {
            required: true
        }
    }
});