Vue.js • Chapter 15 • Foundations to Advanced

Template Refs

Each topic includes substantial explanation, ten focused examples, its own Vue code example, step-by-step reasoning, expected behavior, and practice.

5 topics50 teaching examplesCode example per topic10 Q&A

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15.1 DOM Template Refs

A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to DOM Template Refs and trace how it changes the rendered interface. In Chapter 15, trace the value or control flow from its source to the rendered interface so you can explain why Vue changes the screen.

For DOM Template Refs in Chapter 15, inspect reactive dependencies, update timing, derived values, side effects, and cleanup. Keep writable state ownership explicit, derive values when possible, and separate display calculations from network, DOM, storage, timer, or other external work.

This lesson connects DOM Template Refs to template refs. Start with one working case, verify the expected output, then add one edge case and explain what Vue tracks, reuses, creates, removes, or updates.

Concept in plain language

10 teaching examples

Example 1: Smallest useful case
Build the smallest shopping cart that demonstrates DOM Template Refs. Keep one input and one visible result, then explain reactive dependencies, update timing, derived values, side effects, and cleanup. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to DOM Template Refs and trace how it changes the rendered interface. This is example 1 for Chapter 15, topic 1.
Example 2: Change one reactive value
Change one value involved in DOM Template Refs inside the lesson tracker. Predict what Vue will update before running it, then compare the prediction with the rendered result.
Example 3: Parent-child comparison
Use DOM Template Refs across two components in the booking form. Compare which component owns the writable data and which component only receives or presents it.
Example 4: Edge case
Add an empty, missing, invalid, delayed, or rapidly changing value to the message panel. Handle the DOM Template Refs edge case explicitly instead of leaving stale output.
Example 5: Accessibility review
Use DOM Template Refs in the admin table while checking semantic HTML, labels, focus order, keyboard access, and understandable status feedback. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to DOM Template Refs and trace how it changes the rendered interface. This is example 5 for Chapter 15, topic 1.
Example 6: State ownership review
Remove duplicated state from the photo gallery. For DOM Template Refs, derive values when possible and keep the writable source with the component or store that owns it.
Example 7: Slow-network scenario
Assume the notification center has a slow request while using DOM Template Refs. Decide what remains interactive, what shows pending feedback, and how stale responses are prevented.
Example 8: Refactoring exercise
Extract the DOM Template Refs responsibility from a crowded task board into a focused component or composable with a narrow API.
Example 9: Performance experiment
Measure the language selector before optimizing DOM Template Refs. Check reactive work, repeated calculations, list size, component updates, and user-visible delay.
Example 10: Production review
Review DOM Template Refs in the quiz screen for errors, security, localization, RTL, narrow screens, accessibility, and what monitoring should report. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to DOM Template Refs and trace how it changes the rendered interface. This is example 10 for Chapter 15, topic 1.

Vue code example

<script setup>
import { ref } from 'vue'
const topic = "DOM Template Refs"
const active = ref(false)
</script>
<template>
  <section><h2>{{ topic }}</h2><button :aria-pressed="active" @click="active=!active">Toggle state</button><p>{{ active ? 'Active' : 'Inactive' }}</p></section>
</template>

Step-by-step code explanation

Identify the Vue responsibility demonstrated by DOM Template Refs.
Read the reactive state, props, route/store input, or injected value before the template.
Trace the event, dependency, watcher, lifecycle hook, or navigation action that changes the display.
Test one normal path and one edge case, including cleanup when external work is involved.
Confirm accessibility, mobile width, and RTL behavior for user-facing controls and translated text.

Expected behavior: A small Vue interface demonstrates DOM Template Refs and updates according to the interaction or data in the example.

Practice exercise

Create a small Vue feature focused on DOM Template Refs from Chapter 15. Predict the result before running it, test one edge case, and explain which reactive value, prop, event, route, store, or lifecycle step caused the update. Then check accessibility, narrow-screen width, and RTL behavior where relevant.

15.2 Component Template Refs

A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Component Template Refs and trace how it changes the rendered interface. In Chapter 15, trace the value or control flow from its source to the rendered interface so you can explain why Vue changes the screen.

For Component Template Refs in Chapter 15, inspect reactive dependencies, update timing, derived values, side effects, and cleanup. Keep writable state ownership explicit, derive values when possible, and separate display calculations from network, DOM, storage, timer, or other external work.

This lesson connects Component Template Refs to template refs. Start with one working case, verify the expected output, then add one edge case and explain what Vue tracks, reuses, creates, removes, or updates.

Concept in plain language

10 teaching examples

Example 1: Smallest useful case
Build the smallest message panel that demonstrates Component Template Refs. Keep one input and one visible result, then explain reactive dependencies, update timing, derived values, side effects, and cleanup. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Component Template Refs and trace how it changes the rendered interface. This is example 1 for Chapter 15, topic 2.
Example 2: Change one reactive value
Change one value involved in Component Template Refs inside the admin table. Predict what Vue will update before running it, then compare the prediction with the rendered result.
Example 3: Parent-child comparison
Use Component Template Refs across two components in the photo gallery. Compare which component owns the writable data and which component only receives or presents it.
Example 4: Edge case
Add an empty, missing, invalid, delayed, or rapidly changing value to the notification center. Handle the Component Template Refs edge case explicitly instead of leaving stale output.
Example 5: Accessibility review
Use Component Template Refs in the task board while checking semantic HTML, labels, focus order, keyboard access, and understandable status feedback. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Component Template Refs and trace how it changes the rendered interface. This is example 5 for Chapter 15, topic 2.
Example 6: State ownership review
Remove duplicated state from the language selector. For Component Template Refs, derive values when possible and keep the writable source with the component or store that owns it.
Example 7: Slow-network scenario
Assume the quiz screen has a slow request while using Component Template Refs. Decide what remains interactive, what shows pending feedback, and how stale responses are prevented.
Example 8: Refactoring exercise
Extract the Component Template Refs responsibility from a crowded analytics view into a focused component or composable with a narrow API.
Example 9: Performance experiment
Measure the support form before optimizing Component Template Refs. Check reactive work, repeated calculations, list size, component updates, and user-visible delay.
Example 10: Production review
Review Component Template Refs in the course dashboard for errors, security, localization, RTL, narrow screens, accessibility, and what monitoring should report. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Component Template Refs and trace how it changes the rendered interface. This is example 10 for Chapter 15, topic 2.

Vue code example

<script setup>
import { ref } from 'vue'
const topic = "Component Template Refs"
const active = ref(false)
</script>
<template>
  <section><h2>{{ topic }}</h2><button :aria-pressed="active" @click="active=!active">Toggle state</button><p>{{ active ? 'Active' : 'Inactive' }}</p></section>
</template>

Step-by-step code explanation

Identify the Vue responsibility demonstrated by Component Template Refs.
Read the reactive state, props, route/store input, or injected value before the template.
Trace the event, dependency, watcher, lifecycle hook, or navigation action that changes the display.
Test one normal path and one edge case, including cleanup when external work is involved.
Confirm accessibility, mobile width, and RTL behavior for user-facing controls and translated text.

Expected behavior: A small Vue interface demonstrates Component Template Refs and updates according to the interaction or data in the example.

Practice exercise

Create a small Vue feature focused on Component Template Refs from Chapter 15. Predict the result before running it, test one edge case, and explain which reactive value, prop, event, route, store, or lifecycle step caused the update. Then check accessibility, narrow-screen width, and RTL behavior where relevant.

15.3 useTemplateRef

A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to useTemplateRef and trace how it changes the rendered interface. In Chapter 15, trace the value or control flow from its source to the rendered interface so you can explain why Vue changes the screen.

For useTemplateRef in Chapter 15, inspect reactive dependencies, update timing, derived values, side effects, and cleanup. Keep writable state ownership explicit, derive values when possible, and separate display calculations from network, DOM, storage, timer, or other external work.

This lesson connects useTemplateRef to template refs. Start with one working case, verify the expected output, then add one edge case and explain what Vue tracks, reuses, creates, removes, or updates.

Concept in plain language

10 teaching examples

Example 1: Smallest useful case
Build the smallest notification center that demonstrates useTemplateRef. Keep one input and one visible result, then explain reactive dependencies, update timing, derived values, side effects, and cleanup. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to useTemplateRef and trace how it changes the rendered interface. This is example 1 for Chapter 15, topic 3.
Example 2: Change one reactive value
Change one value involved in useTemplateRef inside the task board. Predict what Vue will update before running it, then compare the prediction with the rendered result.
Example 3: Parent-child comparison
Use useTemplateRef across two components in the language selector. Compare which component owns the writable data and which component only receives or presents it.
Example 4: Edge case
Add an empty, missing, invalid, delayed, or rapidly changing value to the quiz screen. Handle the useTemplateRef edge case explicitly instead of leaving stale output.
Example 5: Accessibility review
Use useTemplateRef in the analytics view while checking semantic HTML, labels, focus order, keyboard access, and understandable status feedback. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to useTemplateRef and trace how it changes the rendered interface. This is example 5 for Chapter 15, topic 3.
Example 6: State ownership review
Remove duplicated state from the support form. For useTemplateRef, derive values when possible and keep the writable source with the component or store that owns it.
Example 7: Slow-network scenario
Assume the course dashboard has a slow request while using useTemplateRef. Decide what remains interactive, what shows pending feedback, and how stale responses are prevented.
Example 8: Refactoring exercise
Extract the useTemplateRef responsibility from a crowded profile editor into a focused component or composable with a narrow API.
Example 9: Performance experiment
Measure the search panel before optimizing useTemplateRef. Check reactive work, repeated calculations, list size, component updates, and user-visible delay.
Example 10: Production review
Review useTemplateRef in the shopping cart for errors, security, localization, RTL, narrow screens, accessibility, and what monitoring should report. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to useTemplateRef and trace how it changes the rendered interface. This is example 10 for Chapter 15, topic 3.

Vue code example

<script setup>
import { ref } from 'vue'
const topic = "useTemplateRef"
const active = ref(false)
</script>
<template>
  <section><h2>{{ topic }}</h2><button :aria-pressed="active" @click="active=!active">Toggle state</button><p>{{ active ? 'Active' : 'Inactive' }}</p></section>
</template>

Step-by-step code explanation

Identify the Vue responsibility demonstrated by useTemplateRef.
Read the reactive state, props, route/store input, or injected value before the template.
Trace the event, dependency, watcher, lifecycle hook, or navigation action that changes the display.
Test one normal path and one edge case, including cleanup when external work is involved.
Confirm accessibility, mobile width, and RTL behavior for user-facing controls and translated text.

Expected behavior: A small Vue interface demonstrates useTemplateRef and updates according to the interaction or data in the example.

Practice exercise

Create a small Vue feature focused on useTemplateRef from Chapter 15. Predict the result before running it, test one edge case, and explain which reactive value, prop, event, route, store, or lifecycle step caused the update. Then check accessibility, narrow-screen width, and RTL behavior where relevant.

15.4 Refs inside v-for

A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Refs inside v-for and trace how it changes the rendered interface. In Chapter 15, trace the value or control flow from its source to the rendered interface so you can explain why Vue changes the screen.

For Refs inside v-for in Chapter 15, inspect reactive dependencies, update timing, derived values, side effects, and cleanup. Keep writable state ownership explicit, derive values when possible, and separate display calculations from network, DOM, storage, timer, or other external work.

This lesson connects Refs inside v-for to template refs. Start with one working case, verify the expected output, then add one edge case and explain what Vue tracks, reuses, creates, removes, or updates.

Concept in plain language

10 teaching examples

Example 1: Smallest useful case
Build the smallest quiz screen that demonstrates Refs inside v-for. Keep one input and one visible result, then explain reactive dependencies, update timing, derived values, side effects, and cleanup. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Refs inside v-for and trace how it changes the rendered interface. This is example 1 for Chapter 15, topic 4.
Example 2: Change one reactive value
Change one value involved in Refs inside v-for inside the analytics view. Predict what Vue will update before running it, then compare the prediction with the rendered result.
Example 3: Parent-child comparison
Use Refs inside v-for across two components in the support form. Compare which component owns the writable data and which component only receives or presents it.
Example 4: Edge case
Add an empty, missing, invalid, delayed, or rapidly changing value to the course dashboard. Handle the Refs inside v-for edge case explicitly instead of leaving stale output.
Example 5: Accessibility review
Use Refs inside v-for in the profile editor while checking semantic HTML, labels, focus order, keyboard access, and understandable status feedback. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Refs inside v-for and trace how it changes the rendered interface. This is example 5 for Chapter 15, topic 4.
Example 6: State ownership review
Remove duplicated state from the search panel. For Refs inside v-for, derive values when possible and keep the writable source with the component or store that owns it.
Example 7: Slow-network scenario
Assume the shopping cart has a slow request while using Refs inside v-for. Decide what remains interactive, what shows pending feedback, and how stale responses are prevented.
Example 8: Refactoring exercise
Extract the Refs inside v-for responsibility from a crowded lesson tracker into a focused component or composable with a narrow API.
Example 9: Performance experiment
Measure the booking form before optimizing Refs inside v-for. Check reactive work, repeated calculations, list size, component updates, and user-visible delay.
Example 10: Production review
Review Refs inside v-for in the message panel for errors, security, localization, RTL, narrow screens, accessibility, and what monitoring should report. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Refs inside v-for and trace how it changes the rendered interface. This is example 10 for Chapter 15, topic 4.

Vue code example

<script setup>
import { ref } from 'vue'
const topic = "Refs inside v-for"
const active = ref(false)
</script>
<template>
  <section><h2>{{ topic }}</h2><button :aria-pressed="active" @click="active=!active">Toggle state</button><p>{{ active ? 'Active' : 'Inactive' }}</p></section>
</template>

Step-by-step code explanation

Identify the Vue responsibility demonstrated by Refs inside v-for.
Read the reactive state, props, route/store input, or injected value before the template.
Trace the event, dependency, watcher, lifecycle hook, or navigation action that changes the display.
Test one normal path and one edge case, including cleanup when external work is involved.
Confirm accessibility, mobile width, and RTL behavior for user-facing controls and translated text.

Expected behavior: A small Vue interface demonstrates Refs inside v-for and updates according to the interaction or data in the example.

Practice exercise

Create a small Vue feature focused on Refs inside v-for from Chapter 15. Predict the result before running it, test one edge case, and explain which reactive value, prop, event, route, store, or lifecycle step caused the update. Then check accessibility, narrow-screen width, and RTL behavior where relevant.

15.5 Ref Timing

A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Ref Timing and trace how it changes the rendered interface. In Chapter 15, trace the value or control flow from its source to the rendered interface so you can explain why Vue changes the screen.

For Ref Timing in Chapter 15, inspect reactive dependencies, update timing, derived values, side effects, and cleanup. Keep writable state ownership explicit, derive values when possible, and separate display calculations from network, DOM, storage, timer, or other external work.

This lesson connects Ref Timing to template refs. Start with one working case, verify the expected output, then add one edge case and explain what Vue tracks, reuses, creates, removes, or updates.

Concept in plain language

10 teaching examples

Example 1: Smallest useful case
Build the smallest course dashboard that demonstrates Ref Timing. Keep one input and one visible result, then explain reactive dependencies, update timing, derived values, side effects, and cleanup. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Ref Timing and trace how it changes the rendered interface. This is example 1 for Chapter 15, topic 5.
Example 2: Change one reactive value
Change one value involved in Ref Timing inside the profile editor. Predict what Vue will update before running it, then compare the prediction with the rendered result.
Example 3: Parent-child comparison
Use Ref Timing across two components in the search panel. Compare which component owns the writable data and which component only receives or presents it.
Example 4: Edge case
Add an empty, missing, invalid, delayed, or rapidly changing value to the shopping cart. Handle the Ref Timing edge case explicitly instead of leaving stale output.
Example 5: Accessibility review
Use Ref Timing in the lesson tracker while checking semantic HTML, labels, focus order, keyboard access, and understandable status feedback. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Ref Timing and trace how it changes the rendered interface. This is example 5 for Chapter 15, topic 5.
Example 6: State ownership review
Remove duplicated state from the booking form. For Ref Timing, derive values when possible and keep the writable source with the component or store that owns it.
Example 7: Slow-network scenario
Assume the message panel has a slow request while using Ref Timing. Decide what remains interactive, what shows pending feedback, and how stale responses are prevented.
Example 8: Refactoring exercise
Extract the Ref Timing responsibility from a crowded admin table into a focused component or composable with a narrow API.
Example 9: Performance experiment
Measure the photo gallery before optimizing Ref Timing. Check reactive work, repeated calculations, list size, component updates, and user-visible delay.
Example 10: Production review
Review Ref Timing in the notification center for errors, security, localization, RTL, narrow screens, accessibility, and what monitoring should report. A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to Ref Timing and trace how it changes the rendered interface. This is example 10 for Chapter 15, topic 5.

Vue code example

<script setup>
import { ref } from 'vue'
const topic = "Ref Timing"
const active = ref(false)
</script>
<template>
  <section><h2>{{ topic }}</h2><button :aria-pressed="active" @click="active=!active">Toggle state</button><p>{{ active ? 'Active' : 'Inactive' }}</p></section>
</template>

Step-by-step code explanation

Identify the Vue responsibility demonstrated by Ref Timing.
Read the reactive state, props, route/store input, or injected value before the template.
Trace the event, dependency, watcher, lifecycle hook, or navigation action that changes the display.
Test one normal path and one edge case, including cleanup when external work is involved.
Confirm accessibility, mobile width, and RTL behavior for user-facing controls and translated text.

Expected behavior: A small Vue interface demonstrates Ref Timing and updates according to the interaction or data in the example.

Practice exercise

Create a small Vue feature focused on Ref Timing from Chapter 15. Predict the result before running it, test one edge case, and explain which reactive value, prop, event, route, store, or lifecycle step caused the update. Then check accessibility, narrow-screen width, and RTL behavior where relevant.

Chapter 15 review — 10 questions and answers

1. What is the purpose of DOM Template Refs?

Answer: A ref stores a reactive value; JavaScript uses .value while templates usually unwrap it automatically. In Chapter 15, apply this definition specifically to DOM Template Refs and trace how it changes the rendered interface.

2. What should you inspect when DOM Template Refs behaves unexpectedly?