Dynamic attribute names in Vue - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does 'dynamic attribute names' mean in Vue?

It means you can set an attribute name on an element using a variable or expression, so the attribute changes based on your data.

beginner

How do you bind a dynamic attribute name in Vue template?

Use the v-bind directive with square brackets around the attribute name, like <div v-bind:[attrName]="value">.

intermediate

Why use dynamic attribute names in Vue?

To make your components flexible and reusable by changing attributes like id, class, or aria-label based on data or user input.

beginner

Example: What does <button v-bind:[buttonType]="true"> do if buttonType = 'disabled'?

It adds the disabled attribute to the button, making it disabled because the attribute name is 'disabled' and its value is true.

intermediate

Can dynamic attribute names be used with event listeners in Vue?

Yes, you can use v-on with dynamic event names like v-on:[eventName]="handler" to listen to different events based on data.

How do you bind a dynamic attribute name in Vue?

A v-bind:[attributeName]

B v-bind(attributeName)

C :attributeName

D v-bind.attributeName

Use v-bind with square brackets around the attribute name to bind it dynamically.

What happens if you write

and attr = 'title'?

A An error occurs because attr is a string.

B The div gets an attribute named 'attr' with value 'value'.

C The div gets a title attribute with the value of 'value'.

D The div gets no new attribute.

The attribute name is taken from the variable attr, so it becomes title with the given value.

Can dynamic attribute names be used to set ARIA attributes in Vue?

A Yes, to improve accessibility dynamically.

B No, ARIA attributes must be static.

C Only for aria-label, not others.

D Only in Vue 2, not Vue 3.

Dynamic attribute names can set any attribute, including ARIA, to help accessibility.

Which Vue directive allows dynamic event names?

A v-bind:[eventName]

B v-on:[eventName]

C v-event:[eventName]

D v-model:[eventName]

v-on with square brackets lets you bind event listeners dynamically.

What is the benefit of using dynamic attribute names in Vue?

A Improves CSS styling automatically.

B Disables reactivity for that attribute.

C Prevents all runtime errors.

D Makes components more flexible and reusable.

Dynamic attribute names let you change attributes based on data, making components flexible.

Explain how to use dynamic attribute names in Vue templates and why they are useful.

Think about how you can change attribute names based on data.

Describe how dynamic attribute names can improve accessibility in Vue applications.

Consider how accessibility attributes might change based on context.

Practice

1. What does v-bind:[attrName] do in Vue?

easy

A. Creates a new component named attrName.

B. Binds the attribute literally named 'attrName' to the element.

C. Binds a static attribute called 'v-bind'.

D. Binds an attribute with a name stored in the variable attrName dynamically.

Solution

1. Step 1: Understand v-bind usage

   v-bind is used to bind attributes dynamically in Vue templates.

2. Step 2: Analyze dynamic attribute syntax

   Using square brackets like v-bind:[attrName] means the attribute name is taken from the variable attrName, not a fixed string.

3. Final Answer:

   Binds an attribute with a name stored in the variable attrName dynamically. -> Option D

4. Quick Check:

   Dynamic attribute name = variable inside brackets [OK]

Hint: Square brackets mean attribute name is from a variable [OK]

Common Mistakes:

• Thinking v-bind:[attrName] binds attribute literally named 'attrName'
• Confusing dynamic binding with static attribute binding
• Assuming it creates a new component
• Using v-bind without brackets for dynamic names

2. Which of the following is the correct syntax to bind a dynamic attribute named by the variable attr in Vue?

easy

A. <div v-bind:[attr]>

B. <div v-bind:attr>

C. <div :attr>

D. <div :[attr]>

Solution

1. Step 1: Recall dynamic attribute binding syntax

   Dynamic attribute names require square brackets around the variable name inside v-bind or shorthand :.

2. Step 2: Check each option

   <div v-bind:attr> binds a static attribute named 'attr'. <div v-bind:[attr]> correctly uses v-bind:[attr]. <div :attr> binds a static attribute named 'attr'. <div :[attr]> is invalid syntax.

3. Final Answer:

   <div v-bind:[attr]> -> Option A

4. Quick Check:

   Use brackets for dynamic attribute names [OK]

Hint: Use brackets around variable for dynamic attribute [OK]

Common Mistakes:

• Omitting brackets for dynamic attribute names
• Using shorthand without brackets incorrectly
• Confusing static and dynamic attribute binding

3. Given this Vue template snippet:

<template>
  <button v-bind:[dynamicAttr]="value">Click</button>
</template>

<script setup>
const dynamicAttr = 'aria-label'
const value = 'Submit Button'
</script>

What attribute will the rendered button have?

medium

A. value="Submit Button"

B. dynamicAttr="Submit Button"

C. aria-label="Submit Button"

D. No attribute will be added

Solution

1. Step 1: Identify the dynamic attribute name

   The variable dynamicAttr holds the string 'aria-label', so the attribute name will be 'aria-label'.

2. Step 2: Understand the binding value

   The value bound to this attribute is the string 'Submit Button'.

3. Final Answer:

   aria-label="Submit Button" -> Option C

4. Quick Check:

   Variable value used as attribute name [OK]

Hint: Variable value becomes attribute name, value assigned as usual [OK]

Common Mistakes:

• Using variable name as attribute name literally
• Confusing attribute name with value
• Expecting no attribute added

4. What is wrong with this Vue template code?

<div v-bind:dynamicAttr="value">Hello</div>

<script setup>
const dynamicAttr = 'title'
const value = 'Greeting'
</script>

medium

A. It will cause a syntax error because v-bind needs brackets.

B. It will bind an attribute literally named 'dynamicAttr', not 'title'.

C. It will bind the attribute 'value' instead of 'title'.

D. There is no error; it works as expected.

Solution

1. Step 1: Check the binding syntax

   Without brackets, v-bind:dynamicAttr binds an attribute literally named 'dynamicAttr'.

2. Step 2: Understand dynamic attribute binding

   To use the variable's value as attribute name, brackets are required: v-bind:[dynamicAttr].

3. Final Answer:

   It will bind an attribute literally named 'dynamicAttr', not 'title'. -> Option B

4. Quick Check:

   Missing brackets means static attribute name [OK]

Hint: Use brackets for dynamic attribute names, else static name used [OK]

Common Mistakes:

• Forgetting brackets for dynamic attribute names
• Assuming variable name is used as attribute name
• Thinking this causes syntax error

5. You want to create a Vue component that accepts a prop attrName and attrValue, then binds the attribute named by attrName with attrValue on a <div>. Which code correctly implements this?

hard

A. <template>
<div :[attrName]="attrValue">Content</div>
</template>

<script setup>
const props = defineProps(['attrName', 'attrValue'])
</script>

B. <template>
<div v-bind:attrName="attrValue">Content</div>
</template>

<script setup>
const props = defineProps(['attrName', 'attrValue'])
</script>

C. <template>
<div :attrName="attrValue">Content</div>
</template>

<script setup>
const props = defineProps(['attrName', 'attrValue'])
</script>

D. <template>
<div v-bind:[attrName]="attrValue">Content</div>
</template>

<script setup>
const props = defineProps(['attrName', 'attrValue'])
</script>

Solution

1. Step 1: Understand dynamic attribute binding with props

   To bind an attribute dynamically using a prop, use the shorthand : with brackets around the prop name: :[attrName].

2. Step 2: Check each option's syntax

   <template>
     <div v-bind:[attrName]="attrValue">Content</div>
   </template>
   
   <script setup>
   const props = defineProps(['attrName', 'attrValue'])
   </script>

   correctly uses quotes around attrValue.

   <template>
     <div v-bind:attrName="attrValue">Content</div>
   </template>
   
   <script setup>
   const props = defineProps(['attrName', 'attrValue'])
   </script>

   and C bind static attribute 'attrName'.

   <template>
     <div :attrName="attrValue">Content</div>
   </template>
   
   <script setup>
   const props = defineProps(['attrName', 'attrValue'])
   </script>

   and

   <template>
     <div :[attrName]="attrValue">Content</div>
   </template>
   
   <script setup>
   const props = defineProps(['attrName', 'attrValue'])
   </script>

   correctly use :[attrName]="attrValue" with props defined, but

   <template>
     <div :[attrName]="attrValue">Content</div>
   </template>
   
   <script setup>
   const props = defineProps(['attrName', 'attrValue'])
   </script>

   uses the shorthand syntax preferred in Vue.

3. Final Answer:

   <div :[attrName]="attrValue">Content</div> -> Option A

4. Quick Check:

   Use :[attrName]="attrValue" for dynamic binding [OK]

Hint: Use :[variable]="value" syntax for dynamic attribute binding [OK]

Common Mistakes:

• Omitting quotes around binding value
• Using static attribute name instead of dynamic
• Confusing shorthand and full syntax