App.vue
FoodItem.vue
main.js
 
<template>
  <h1>Food</h1>
  <p>Toggle with the 'Favorite' button to emit an event from 'FoodItem.vue' to 'App.vue' with the built-in Vue method '$emit()'.</p>
  <div id="wrapper">
    <food-item
      v-for="x in foods"
      :key="x.name"
      :food-name="x.name"
      :food-desc="x.desc"
      :is-favorite="x.favorite"
      @toggle-favorite="receiveEmit"/>
  </div> 
</template>

<script>
export default {
  data() { 
    return {
      foods: [
        { name: 'Apples', desc: 'Apples are a type of fruit that grow on trees.', favorite: true},
        { name: 'Pizza', desc: 'Pizza has a bread base with tomato sauce, cheese, and toppings on top.', favorite: false},
        { name: 'Rice', desc: 'Rice is a type of grain that people like to eat.', favorite: false},
        { name: 'Fish', desc: 'Fish is an animal that lives in water.', favorite: true},
        { name: 'Cake', desc: 'Cake is something sweet that tastes good.', favorite: false}
      ]
    };
  },
  methods: {
    receiveEmit() {
      alert('Hello World!');
    }
  }
}
</script>

<style>
  #wrapper {
    display: flex;
    flex-wrap: wrap;
  }
  #wrapper > div {
    border: dashed black 1px;
    flex-basis: 120px;
    margin: 10px;
    padding: 10px;
    background-color: lightgreen;
  }
</style>                  
<template>
    <div>
        <h2>
            {{ foodName }}
            <img src="/img_quality.svg" v-show="foodIsFavorite">
        </h2>
        <p>{{ foodDesc }}</p>
        <button @click="toggleFavorite">Favorite</button>
    </div>
</template>

<script>
export default {
    props: ['foodName','foodDesc','isFavorite'],
    data() {
        return {
            foodIsFavorite: this.isFavorite
        }
    },
    methods: {
        toggleFavorite() {
            this.$emit('toggle-favorite');
        }
    }
};
</script>

<style>
    img {
        height: 1.5em;
        float: right;
    }
</style>                  
import { createApp } from 'vue'

import App from './App.vue'
import FoodItem from './components/FoodItem.vue'

const app = createApp(App)

app.component('food-item', FoodItem)

app.mount('#app')
                  
http://localhost:5173/