Скачать или смотреть How to Ensure Unique Email Validation in Ruby on Rails Before Saving a User

Learn to validate the uniqueness of a field in Ruby on Rails, specifically handling hashed emails before saving a user. Follow our step-by-step breakdown for successful implementation.
---
This video is based on the question https://stackoverflow.com/q/73092484/ asked by the user 'Rawley Fowler' ( https://stackoverflow.com/u/12283863/ ) and on the answer https://stackoverflow.com/a/73093268/ provided by the user 'Rawley Fowler' ( https://stackoverflow.com/u/12283863/ ) 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 validate uniqueness of a field before save, if the field is changed before save?

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.
---
How to Ensure Unique Email Validation in Ruby on Rails Before Saving a User

One common challenge when developing applications with Ruby on Rails is validating the uniqueness of a field, especially when that field undergoes changes before being saved to a database—such as when we hash sensitive data like emails. In this guide, we'll explore how to effectively validate the uniqueness of a hashed email for a User model in Ruby on Rails, ensuring that your application maintains data integrity while improving user experience.

The Challenge

Imagine you have a User model where users can register with their email and password. For security reasons, you want to hash the email before saving it to the database. However, you also need to ensure that once hashed, the email is still unique within the database.
The following steps outline the requirements:

Validate that the email is well-formed according to standard regex patterns.

Hash the email using SHA2.

Confirm that the hashed email is unique within the table before saving it.

Solution Breakdown

To achieve this, we'll implement the following modifications within your User model. Let’s go through each step with the relevant code snippets.

1. Setting Up Validations

First, we'll ensure that the necessary validations are in place for the email and password. This includes formatting checks, presence validation, and uniqueness checks. Here’s how you could set it up:

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

2. Implementing Callbacks and Custom Validations

In the code snippet above, we perform several key functions:

Call to before_validation: This ensures that the email is in lowercase before validation to prevent duplicates due to case sensitivity.

Hashing the email: The digest_email method hashes the email, ensuring that only hashed values are stored in the database.

Custom validation method: The verify_email_hash_uniqueness method checks the existence of the hashed email in the database, adding an error if it finds a duplicate.

Conclusion

With these steps, you can confidently ensure that user registrations maintain both integrity and security within your Ruby on Rails application. By validating the email formatting, hashing it, and subsequently checking for uniqueness, you establish a robust system that safeguards against duplicate entries while also enhancing user experience.

Implementing these techniques not only simplifies your controller logic but also maintains clear data management strategies. Embrace the power of effective validations and empower your application with a reliable registration process!