UniqueID binding in knockout

问题:

I'm trying to figure out how to duplicate the functionality of the Unique Name binding for an element's ID (to get pretty validation working)

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

回答1:

The knockout source for uniqueName is

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

            // Workaround IE 6 issue - http://www.matts411.com/post/setting_the_name_attribute_in_ie_dom/
            if (ko.utils.isIe6)
                element.mergeAttributes(document.createElement("<input name='" + element.name + "'/>"), false);
        }
    }
};
ko.bindingHandlers['uniqueName'].currentIndex = 0;

So I think you should have this (note ID should be id, IE6 stuff removed, and uniqueName changed to uniqueId)

ko.bindingHandlers['uniqueId'] = {
    'init': function (element, valueAccessor) {
        if (valueAccessor()) {
            element.id = "ko_unique_" + (++ko.bindingHandlers['uniqueId'].currentIndex);           
        }
    }
};
ko.bindingHandlers['uniqueId'].currentIndex = 0;