count timer in vue js code example

Example 1: vue js count down timer

<template>
    {{ timerCount }}
</template>

<script>

    export default {

        data() {
            return {
                timerEnabled: true,
                timerCount: 30
            }
        },

        watch: {

            timerEnabled(value) {
                if (value) {
                    setTimeout(() => {
                        this.timerCount--;
                    }, 1000);
                }
            },

            timerCount: {
                handler(value) {

                    if (value > 0 && this.timerEnabled) {
                        setTimeout(() => {
                            this.timerCount--;
                        }, 1000);
                    }

                },
                immediate: true // This ensures the watcher is triggered upon creation
            }

        }

        methods: {

            play() {
                this.timerEnabled = true;
            },

            pause() {
                this.timerEnabled = false;
            }

        }

    }

</script>

Example 2: vue js count down timer

<template>
  <div>
    <slot :hour="hour" :min="min" :sec="sec"></slot>
  </div>
</template>

<script>
export default {
  props : {
    endDate : {  // pass date object till when you want to run the timer
      type : Date,
      default(){
        return new Date()
      }
    },
    negative : {  // optional, should countdown after 0 to negative
      type : Boolean,
      default : false
    }
  },
  data(){
    return{
      now : new Date(),
      timer : null
    }
  },
  computed:{
    hour(){
      let h = Math.trunc((this.endDate - this.now) / 1000 / 3600);
      return h>9?h:'0'+h;
    },
    min(){
      let m = Math.trunc((this.endDate - this.now) / 1000 / 60) % 60;
      return m>9?m:'0'+m;
    },
    sec(){
      let s = Math.trunc((this.endDate - this.now)/1000) % 60
      return s>9?s:'0'+s;
    }
  },
  watch : {
    endDate : {
      immediate : true,
      handler(newVal){
        if(this.timer){
          clearInterval(this.timer)
        }
        this.timer = setInterval(()=>{
          this.now = new Date()
          if(this.negative)
            return
          if(this.now > newVal){
            this.now = newVal
            this.$emit('endTime')
            clearInterval(this.timer)
          }
        }, 1000)
      }
    }
  },
  beforeDestroy(){
    clearInterval(this.timer)
  }
}
</script>