click outside

click-outside.vue

Vue.directive('click-outside', {
  bind () {
      this.event = event => this.vm.$emit(this.expression, event)
      this.el.addEventListener('click', this.stopProp)
      document.body.addEventListener('click', this.event)
  },   
  unbind() {
    this.el.removeEventListener('click', this.stopProp)
    document.body.removeEventListener('click', this.event)
  },

  stopProp(event) { event.stopPropagation() }
})
Usage:

<div v-click-outside="nameOfCustomEventToCall">
  Some content
</div>
In the component:

events: {
  nameOfCustomEventToCall: function (event) {
    // do something - probably hide the dropdown menu / modal etc.
  }
}