Скачать или смотреть How to Correctly Pass v-model Values to Child Components in Vue 3

Discover how to pass `v-model` values from a parent component to its descendant child components in Vue 3 effectively.
---
This video is based on the question https://stackoverflow.com/q/71639443/ asked by the user 'Nagisa Ando' ( https://stackoverflow.com/u/12332180/ ) and on the answer https://stackoverflow.com/a/71643947/ provided by the user 'jacob_frankovic' ( https://stackoverflow.com/u/13935477/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to pass v-model value to child's child component in Vue 3

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding How to Pass v-model Values to Child Components in Vue 3

When working with Vue 3, a common question that developers encounter is how to effectively pass values using v-model from a parent component to a child, and further down to a grandchild component. If you've ever found that you're unable to see the expected data in your forms, you're not alone. This guide will walk you through the process, breaking it down into easy-to-understand sections, so you can effectively pass these values and ensure your inputs reflect the right data.

The Problem

Let’s set the scene: you have a parent component that holds a v-model state. You're trying to pass this state down two levels to a grandchild component, but you find that the expected value doesn’t appear in your inputs. Below is the initial structure you've likely encountered:

Parent Component (Example)

[[See Video to Reveal this Text or Code Snippet]]

Child Component (Example)

[[See Video to Reveal this Text or Code Snippet]]

Grandchild Component (Example)

[[See Video to Reveal this Text or Code Snippet]]

The issue arises because the value from the parent is not reaching the grandchild, and in this case, the input remains empty. Let’s dive into understanding why this happens and how to fix it.

Understanding Vue Prop Names

The core of the issue lies in the names assigned to props at each level of your component hierarchy. When passing values, prop names must match precisely; otherwise, the components won’t share data as expected.

The misalignment in prop names:

In the AnotherChildComponent, the prop is defined as modelValue.

However, in the ChildComponent, you used value to pass that down.

This mismatch is why the grandchild component falls back to its default value of an empty string.

The Solution: Correcting Prop Names

To ensure that the data flows correctly from the parent to the grandchild, you need to maintain consistency in your prop names throughout your components. Here’s how you can rectify the situation:

Step 1: Update the Child Component

Update the prop name in the ChildComponent to match the prop name in the AnotherChildComponent. Here’s what it should look like:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Maintain Consistency in Prop Definitions

Ensure that the prop is properly defined in both Child and AnotherChild components, as shown in the examples below:

[[See Video to Reveal this Text or Code Snippet]]

Final Structure

After making these adjustments, the structure should look something like this:

Parent Component

[[See Video to Reveal this Text or Code Snippet]]

Child Component

[[See Video to Reveal this Text or Code Snippet]]

Grandchild Component

[[See Video to Reveal this Text or Code Snippet]]

With this setup, name is effectively passed from the parent to the child and then to the grandchild, ensuring that the input correctly reflects its value.

Conclusion

By ensuring that the prop names align perfectly across your components, you can successfully pass v-model values in Vue 3. Remember, clarity in your naming conventions is key to preventing confusion and bugs down the line. If you face similar issues in the future, refer back to this guide to troubleshoot and find resolution quickly.

With these clear steps, you should now be able to pass values through your components with confidence, improving the responsiveness and interactivity of your applications!