Скачать или смотреть Fixing the Vue 3 Modal: How to Avoid Old Data Coming Back When Reopened

Discover how to manage Vue 3 modals effectively by resetting the data when reopened. Learn the solution to avoid old data appearing in modal forms.
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This video is based on the question https://stackoverflow.com/q/64183799/ asked by the user 'Bulent' ( https://stackoverflow.com/u/4925548/ ) and on the answer https://stackoverflow.com/a/64184034/ provided by the user 'Michal Levý' ( https://stackoverflow.com/u/381282/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Fixing the Vue 3 Modal: Preventing Old Data from Reappearing

When developing applications using Vue 3 and Vuex, one might encounter the frustrating issue of a modal displaying outdated data when it's reopened. If you’re facing this challenge, you’re not alone! In this post, we will clarify the problem and guide you through a step-by-step solution to ensure your modal consistently begins with fresh data every time it opens.

Understanding the Problem

The main issue arises when you open a modal for creating or editing data (in our case, a car object). Here's a simplified breakdown of the scenario:

Opening the Modal: When the modal for creating a car is opened, it fetches a default object filled with initial values.

Filling Out Form Fields: As users fill the form, these input fields update the Vuex store and modify the car object.

Closing the Modal: Users close the modal, which attempts to reset the car object to an empty object ({}). However, upon reopening the modal, the old data still appears.

This behavior suggests the car object in the Vuex store is incorrectly referenced to the defaults object, leading to the retention of stale data.

The Root Cause

The problem is not a Vue or Vuex issue but rather a JavaScript object reference issue. When you set state.car to state.defaults, you are pointing state.car to the same object as state.defaults. Consequently, any modifications in the modal also change state.defaults, and when reopening the modal, you see those changes reflected, leading to the confusion of encountering previously filled data.

A Step-By-Step Solution

Let’s walk through the resolution to ensure that each time you open the modal, it starts with fresh, unmodified default values.

Step 1: Modify the Vuex Action

In your Vuex actions, change your method for filling the defaults to spread the properties into a new object. This way, you'll avoid directly referencing the defaults.

Original Code:

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

Updated Code:

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

Step 2: Ensure Proper Resetting of State

When closing the modal, setting state.car to a new object is appropriate but ensure you're not unintentionally linking it back to the defaults. After the modal is closed, you can keep the reset logic the same:

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

Step 3: Testing with Vue Dev Tools

To ensure your solution works as intended:

Open the Vue Dev Tools in your browser.

Inspect the Vuex store to see the car object when the modal opens and closes.

Confirm that after closing the modal, the car object is indeed empty before reopening the modal.

Conclusion

By spreading the properties of defaults into a new object, you ensure that the data presented in your modal is fresh and untouched when reopened. This small change resolves the problem of displaying stale data, making your application more intuitive and user-friendly.

By following these steps, you can maintain a clean data state in your Vue 3 application and prevent old data from showing up in your modals. Happy coding!