knockout binding how to remove an attribute

Question

Let's say I have an Html element

<element testattribute='a'></element>

I know I can pass the value of testattribute using a binding like this:

<element data-bind="attr: { testattribute: 'a'}></element>

But how can I completely remove this attribute through the binding. So if the original value was

 <element testattribute: 'a'></element>

my end result should be

<element></element>

Answer 1

The attr binding in KO will actually remove the attribute if the value is false, null, or undefined. So, if you bind against an observable and then set it to one of those values (not empty string), then the attribute will be removed.

Answer 2

you should do this ternary inline because form not accepts several checked radio button and it will ignore the knockout comments so none would be checked to avoid do like:

<input type="radio" data-bind="attr:{'checked':($data.amount > 0) ? 'checked' : false}" id="q156" name="foo" value="positive" />

this will set accurate!