I am trying to validate that at least 1 checkbox was selected using the Aurelia validator. I was assuming that using the minItems() method would be sufficient but it seems I can only make this work by a 'hack' using a hidden element pointing to my array. Does anyone know of a more simple approach to handling this?
When dealing with groups of radios or checkboxes it's easiest to put the validation on the group instead of each individual input element. This approach requires building a custom element for "checkbox-group" and/or "radio-group". Here's an example of a checkbox group with validation:
checkboxes component that is compatible with validation
<label id="color1">
Colors 1:
<checkbox-select items-source.bind="colors"
value.bind="colors1 & validate"
aria-labelledby="color1">
</checkbox-select>
</label>