checkbox.pt

<div class="checkbox">
  <label for="${field.oid}">
    <input tal:define="name name|field.name;
                       true_val true_val|field.widget.true_val;
                       css_class css_class|field.widget.css_class;
                       style style|field.widget.style;
                       oid oid|field.oid"
           type="checkbox"
           name="${name}" value="${true_val}"
           id="${oid}"
           tal:attributes="checked cstruct == true_val;
                           class css_class;
                           style style;
                           attributes|field.widget.attributes|{};" />

    <span tal:condition="hasattr(field, 'schema') and hasattr(field.schema, 'label')"
          tal:replace="field.schema.label" class="checkbox-label" >
    </span>

  </label>                              
</div>