gistfile1.txt

<template lang="jade">
  #example
    button(@click="greet") Greet
</template>

<script>

export default {
  data () {
    return {
      // note: changing this line won't causes changes
      // with hot-reload because the reloaded component
      // preserves its current state and we are modifying
      // its initial state.
      msg: 'Hello World!!?!'
    }
  },
  methods: {
    greet: (event) => {
      // `this` inside methods point to the Vue instance
      console.log('Hello ' + this.msg + '!') //this is undefined, why????
      // `event` is the native DOM event
      console.log(event.target.tagName)
    }
  }
}
</script>