// addClass adds class to the given element. It retains any other classes that
// the element may have.
func addClass(el dom.Element, class string) {
newClasses := class
if oldClasses := el.GetAttribute("class"); oldClasses != "" {
newClasses = oldClasses + " " + class
}
el.SetAttribute("class", newClasses)
}
// removeClass removes the given class from the element it retains any other
// classes that the element may have.
func removeClass(el dom.Element, class string) {
oldClasses := el.GetAttribute("class")
if oldClasses == class {
// The only class present was the one we want to remove. Remove the class
// attribute entirely.
el.RemoveAttribute("class")
}
classList := strings.Split(oldClasses, " ")
for i, currentClass := range classList {
if currentClass == class {
newClassList := append(classList[:i], classList[i+1:]...)
el.SetAttribute("class", strings.Join(newClassList, " "))
}
}
}