Knockout JS “uniqueName” binding - Same name to two fields

Question

I am using Knockout JS to create an editor. I am using the foreach property to loop around a list in my model.

Answer 1

The uniqueName binding just increments an index and sets the name (with a fix for IE).

It looks like:

ko.bindingHandlers['uniqueName'] = {
    'init': function (element, valueAccessor) {
        if (valueAccessor()) {
            element.name = "ko_unique_" + (++ko.bindingHandlers['uniqueName'].currentIndex);

            // Workaround IE 6/7 issue
            // - https://github.com/SteveSanderson/knockout/issues/197
            // - http://www.matts411.com/post/setting_the_name_attribute_in_ie_dom/
            if (ko.utils.isIe6 || ko.utils.isIe7)
                element.mergeAttributes(document.createElement(""), false);
        }
    }
};

So, you can create a custom binding that uses the last index and sets the appropriate attribute

ko.bindingHandlers.valmsg = {
    init: function(element) {
        element.setAttribute("data-valmsg-for", "ko_unique_" + ko.bindingHandlers.uniqueName.currentIndex);
    }
};

Now, you would just use it like: