Vue v-on direktivasi

<template>
  <h1>v-on Example</h1>
  <div v-bind:class="{ yelClass: bgColor }">
    <p>Click the button to change background color of this DIV box.</p>
    <button v-on:click="bgColor = !bgColor">Click</button>
    <p>bgColor property: "{{ bgColor }}"</p>
  </div>
</template>

Quyida ko‘proq misollarni ko‘ring.

Ta’rif va qo‘llanilishi

v-on direktivasi hodisa tinglovchisini (event listener) biriktirish uchun elementga joylashtiriladi.

v-on yordamida hodisa tinglovchisini biriktirish uchun hodisa turini, har qanday modifikatorni va shu hodisa sodir bo‘lganda ishga tushishi kerak bo‘lgan metod yoki ifodani ko‘rsatishimiz kerak.

Agar v-on oddiy HTML tegiga joylashtirilsa, tinglash uchun belgilashimiz mumkin bo‘lgan hodisa turlari input, click yoki mouseover kabi odatiy hodisalardir.

Agar v-on maxsus komponentga joylashtirilsa, tinglash uchun belgilashimiz mumkin bo‘lgan hodisa turlari shu komponentdan emit qilinadigan maxsus hodisalardir.

v-on: direktivasining qisqa shakli — @.

Modifikatorlar

<template>
  <h1>v-on Example</h1>
  <p>When the '.capture' modifier is used on the parent DIV element, the event is captured first in the parent element when the child element is clicked.</p>
  <p>If the '.capture' modifier is removed from this code, the child element will capture the click event first. This is the default behavior, that the event bubbles up, first in child element, then to the parent.</p>
  <div v-on:click.capture="this.msg.push('parent')" id="parent">
    <p>This is the parent element.</p>
    <div v-on:click="this.msg.push('child')">
      <p>This is the child element. CLICK HERE!</p>
    </div>
  </div>
  <p>The order of when and where the event is captured.</p>
  <ol>
    <li v-for="x in msg">{{ x }}</li>
  </ol>
</template>

<script>
export default {
  data() {
    return {
      msg: []
    };
  }
}
</script>

<style scoped>
div {
  margin: 10px;
  padding: 10px;
  border: dashed black 1px;
}
#parent {
  width: 250px;
  background-color: lightpink;
}
#parent > div {
  cursor: pointer;
  background-color: lightgreen;
}
</style>

<template>
  <h1>v-on Example</h1>
  <p>The '.stop' modifier stops the click event from propagating any further.</p>
  <p>If the '.stop' modifier is removed from this code, the parent element will also capture the click event on the child element.</p>
  <div v-on:click="this.msg.push('parent')" id="parent">
    <p>This is the parent element.</p>
    <div v-on:click.stop="this.msg.push('child')">
      <p>This is the child element. CLICK HERE!</p>
    </div>
  </div>
  <p>The order of when and where the event is captured.</p>
  <ol>
    <li v-for="x in msg">{{ x }}</li>
  </ol>
</template>

<script>
export default {
  data() {
    return {
      msg: []
    };
  }
}
</script>

<style scoped>
div {
  margin: 10px;
  padding: 10px;
  border: dashed black 1px;
}
#parent {
  width: 250px;
  background-color: lightpink;
}
#parent > div {
  cursor: pointer;
  background-color: lightgreen;
}
</style>

<template>
  <h1>v-on Example</h1>
  <p>The '.passive' modifier sets the event handler as passive, and this can enhance performance.</p>
  <div v-on:scroll.passive="this.scrollTimes++" id="parent">
    <p>Scroll here.</p>
    <p>Bladi-bladi-bladi</p>
    <p>potato potato</p>
    <p>Scroll-scroll-scroll</p>
    <p>Scroll more...</p>
  </div>
  <p>Scroll happended {{ scrollTimes }} times.</p>
</template>

<script>
export default {
  data() {
    return {
      scrollTimes: 0
    };
  }
}
</script>

<style scoped>
div {
  margin: 10px;
  padding: 10px;
  border: dashed black 1px;
  width: 200px;
  height: 50px;
  overflow: scroll;
  background-color: lightcoral;
}
</style>

<template>
  <h1>v-on Example</h1>
  <p>The '.once' modifier prevents the event from happening more than once.</p>
  <button v-on:click.once="clickTimes++">Click</button>
  <p>Click event happened {{ clickTimes }} times.</p>
</template>

<script>
export default {
  data() {
    return {
      clickTimes: 0
    };
  }
}
</script>

<template>
  <h1>v-on Example</h1>
  <p>The '.self' modifier is set on the parent element. </p>
  <p>Click on the child element and see how the event propagates past the parent element because the parent click event only reacts to click on the element itself.</p>
  <div v-on:click="addMsg('grandParent')" id="grandParent">
    Grandparent element
    <div v-on:click.self="addMsg('parent')">
      Parent element.
      <div v-on:click="addMsg('child')">
        Child element. CLICK HERE!
      </div>
    </div>
  </div>
  <p>The order of when and where the event is captured.</p>
  <ol>
    <li v-for="x in msg">{{ x }}</li>
  </ol>
</template>

<script>
export default {
  data() {
    return {
      msg: []
    };
  },
  methods: {
    addMsg(txt) {
      this.msg.push(txt);
    }
  }
}
</script>

<style scoped>
div {
  margin: 10px;
  padding: 10px;
  border: dashed black 1px;
  cursor: pointer;
}
#grandParent {
  width: 250px;
  background-color: lightpink;
}
#grandParent > div {
  background-color: lightgreen;
}
#grandParent > div > div {
  background-color: lightskyblue;
}
</style>

<template>
  <h1>v-on Example</h1>
  <p>The '.prevent' modifier is set to prevent the drop down menu to appear when the user does a right mouse button click.</p>
  <div 
    v-on:click.right.prevent="changeColor" 
    v-bind:style="{ backgroundColor: 'hsl(' + bgColor + ',80%,80%)' }">
    <p>Press right mouse button here.</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      bgColor: 0
    }
  },
  methods: {
    changeColor() {
      this.bgColor += 50
    }
  }
}
</script>

<style scoped>
div {
  margin: 10px;
  padding: 10px;
  border: dashed black 1px;
  width: 200px;
}
</style>

<template>
  <h1>v-on Example</h1>
  <p>Hold 'Shift' key and press left mouse button on the image:</p>
  <img v-on:click.left.shift="changeImg" v-bind:src="imgUrl">
</template>

<script>
export default {
  data() {
    return {
      imgFish: true,
      imgUrl: 'img_fish.svg'
    }
  },
  methods: {
    changeImg() {
      this.imgFish = !this.imgFish;
      if (this.imgFish) {
        this.imgUrl = 'img_fish.svg'
      }
      else {
        this.imgUrl = 'img_tiger.svg'
      }
    }
  }
}
</script>

<style scoped>
img {
  width: 200px;
}
</style>