Consider strategy patterns when v-if branches increase in Vue

It is often used in React, but it can also be achieved properly in Vue.

Main points

Think of patterns as being defined by strings
- Example: API communication status: pending | resolve | reject
- Example: SNS icon distribution: twitter | facebook | instagram | github | line
Create components for each pattern

implementation

<script setup lang="ts">
  import { computed, ref } from 'vue';
  import TwitterIcon from './TwitterIcon.vue';
  import FacebookIcon from './FacebookIcon.vue';
  import InstagramIcon from './InstagramIcon.vue';

  type IconType = "twitter" | "facebook" | "instagram";

  const icons = {
    twitter: TwitterIcon,
    facebook: FacebookIcon,
    instagram: InstagramIcon;
  }

  const iconType = ref<IconType>("twitter");

  const currentIconComponent = computed(() => {
    return icons[iconType.value]
  })

  // function showTwitterIcon
  // function showFacebookIcon
  // function showInstagramIcon
</script>

<template>
  <div class="flex gap-1 m-4">
    <button @click="showTwitterIcon">Twitter</button>
    <button @click="showFacebookIcon">Facebook</button>
    <button @click="showInstagramIcon">Instagram</button>
  </div>

  <component :is="currentIconComponent" />
</template>

Points

Object mapping: Mapping pattern strings and components
Dynamic component: Dynamically switched with <component :is="...">
Type Safety: Define patterns in TypeScript with Union Type

summary

If three or more branching patterns occur in v-if, consider a strategy pattern.

Dynamic components make templates cleaner and easier to add new patterns.