Function mergeClassData

static/vuejs/vue.common.js:4236–4243

(child, parent)

}

function mergeClassData (child, parent) {
  return {
    staticClass: concat(child.staticClass, parent.staticClass),
    class: child.class
      ? [child.class, parent.class]
      : parent.class
  }
}

function genClassFromData (data) {
  var dynamicClass = data.class;