Can't use data for fontawesome icons in vue

2 min read 04-10-2024

Can't Use Data for Font Awesome Icons in Vue? Here's Why and How to Fix It!

Are you trying to dynamically display Font Awesome icons in your Vue.js application based on data but hitting a wall? You're not alone. This is a common issue, particularly for beginners, because Vue's reactivity system doesn't always play nicely with how Font Awesome works.

Let's dive into the problem, understand why it happens, and explore the best solution.

The Scenario

Imagine you have a list of items, and you want to display a different Font Awesome icon next to each item based on its category.

<template>
  <ul>
    <li v-for="(item, index) in items" :key="index">
      <i class="fas fa-{{ item.icon }}"></i> {{ item.name }}
    </li>
  </ul>
</template>

<script>
export default {
  data() {
    return {
      items: [
        { name: "Item 1", icon: "star" },
        { name: "Item 2", icon: "heart" },
        { name: "Item 3", icon: "check" },
      ],
    };
  },
};
</script>

This code seems logical, but it won't work as expected. You'll likely see only a single icon, usually the last one in the items array, repeated for every item.

The Problem: Reactivity and String Interpolation

Vue's reactivity system makes it magic, but it relies on detecting changes to your component's data. When you use string interpolation {{ item.icon }} within the class attribute, Vue sees the entire class string as a single piece of data. Any change to item.icon won't trigger a re-render because the class string is effectively static.

The Solution: Dynamic Classes with Computed Properties

The solution is to use dynamic classes in combination with computed properties to make Vue aware of changes within your data:

<template>
  <ul>
    <li v-for="(item, index) in items" :key="index">
      <i :class="getIconClass(item.icon)"></i> {{ item.name }}
    </li>
  </ul>
</template>

<script>
export default {
  data() {
    return {
      items: [
        { name: "Item 1", icon: "star" },
        { name: "Item 2", icon: "heart" },
        { name: "Item 3", icon: "check" },
      ],
    };
  },
  computed: {
    getIconClass(iconName) {
      return ['fas', `fa-${iconName}`];
    },
  },
};
</script>

In this code:

Computed Property getIconClass: We define a computed property getIconClass that takes an iconName (from our data) and returns an array of classes. This makes Vue aware of any changes within the iconName data.
Dynamic Classes: We use the :class binding with the getIconClass computed property. This ensures that the class list is always updated dynamically based on the data.

Additional Tips and Best Practices:

Import Font Awesome: Remember to import the necessary Font Awesome CSS and JavaScript files in your project.
Use Icon Components: For larger projects, consider using Vue components to encapsulate Font Awesome icons and make your code even more maintainable.
Keep it Consistent: Use consistent naming conventions for your icons and classes to make your code readable.

Conclusion

By understanding the limitations of Vue's reactivity system and applying the right techniques, you can easily use dynamic data to display Font Awesome icons in your Vue projects. This approach makes your code more adaptable and user-friendly!

Resources:

Font Awesome Documentation: https://fontawesome.com/docs
Vue.js Documentation: https://vuejs.org/guide/

Can't use data for fontawesome icons in vue