How Can I Use Imported Constant in Template Section in Vue.js

In Vue.js, you can't directly use constants imported into the template section. The template section is primarily for defining the structure of your component's view and for binding data, methods, and computed properties to the DOM elements. However, you can still use constants in your component's JavaScript section and then make them available for use in the template section.

1. Using Data Property

Import the constant.

// constants.js
export const MY_CONSTANT = 'Hello World!';

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Assign to a data property in the component.

<template>
  <div>
    <p>{{ myConstant }}</p>
  </div>
</template>

<script>
import { MY_CONSTANT } from './constants.js';

export default {
  data() {
    return {
      myConstant: MY_CONSTANT
    };
  }
};
</script>

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2. Using Computed Property

Import the constant.

// constants.js
export const MY_CONSTANT = 'Hello World!';

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Define a computed property in the component.

<template>
  <div>
    <p>{{ constantValue }}</p>
  </div>
</template>

<script>
import { MY_CONSTANT } from './constants.js';

export default {
  computed: {
    constantValue() {
      return MY_CONSTANT;
    }
  }
};
</script>

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3. Using Vue's created Hook

Import the constant

// constants.js
export const MY_CONSTANT = 'Hello World!';

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Set the constant as a property in the created hook.

<template>
  <div>
    <p>{{ myConstant }}</p>
  </div>
</template>

<script>
import { MY_CONSTANT } from './constants.js';

export default {
  data() {
    return {
      myConstant: ''
    };
  },
  created() {
    this.myConstant = MY_CONSTANT;
  }
};
</script>

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4. Using Inject/Provide

This approach is suitable for passing constants down to deeply nested components.

Import the constant.

// constants.js
export const MY_CONSTANT = 'Hello World!';

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// constants.js
export const MY_CONSTANT = 'Hello World!';

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In the parent component, provide the constant.

<script>
import { MY_CONSTANT } from './constants.js';

export default {
  provide: {
    constantValue: MY_CONSTANT
  }
};
</script>

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In the child component, inject the constant.

<template>
  <div>
    <p>{{ injectedConstant }}</p>
  </div>
</template>

<script>
export default {
  inject: ['constantValue'],
  computed: {
    injectedConstant() {
      return this.constantValue;
    }
  }
};
</script>

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By using these methods, you can effectively use imported constants within the template section of your Vue.js components. Each method has its own use case, so choose the one that best fits your scenario based on your component structure and requirements.