Working with forms in React can be daunting, especially when it comes to validation and managing state. React Hook Form has emerged as a popular solution due to its simplicity, performance, and flexibility. However, many developers encounter a confusing issue: why does React Hook Form make fields optional by default, and how should you deal with it when you need certain fields to be required?
This blog post breaks down why this happens, the default behavior of React Hook Form, and how to enforce required fields correctly. Whether you’re a beginner or an intermediate React developer, understanding how this library works under the hood will help you build more reliable forms with less frustration.
Understanding React Hook Form’s Default Behavior
React Hook Form is designed to be lightweight and non-intrusive. One of its key principles is that it doesn’t assume anything about your form unless you explicitly tell it to. This includes validation rules like required. That’s why, when you register a field using register("name"), it’s treated as an optional field unless you define validation rules.
This design choice is intentional. By not assuming which fields are required or optional, React Hook Form gives developers full control over validation logic. This approach makes the library more flexible but also means you need to be deliberate when setting rules.
So when people say “React Hook Form makes my fields optional,” the more accurate way to put it is, “React Hook Form treats fields as optional unless told otherwise.” This behavior may surprise developers who are used to frameworks that automatically enforce required fields based on HTML attributes or field types.
How to Make Fields Required Explicitly
If you want to make a field required, you need to pass validation rules into the register function. For example:
<input {...register("email", { required: "Email is required" })} />
In this example, we’re telling React Hook Form that the email field is required and also providing a custom error message. If you don’t pass the required rule, the field will not be validated for presence.
Another method is to use the useForm hook’s mode setting to control when validation occurs—on submit, on blur, or on change. But even with this, the rules must still be defined for each field.
Keep in mind that using native HTML5 attributes like required won’t affect React Hook Form’s internal validation unless you use the shouldUseNativeValidation option. So always define your validation rules explicitly using the register method.
Common Mistakes and Misunderstandings
One of the most common mistakes developers make is assuming that all fields are required by default. Another issue is trying to use required directly in JSX, like this:
<input required {...register("name")} />
While this will work for HTML validation, React Hook Form will not recognize it unless you pass required through the register method’s options. This means the field could still be treated as optional during form validation, especially if you’re handling errors through formState.errors.
Another confusion arises when using default values. If a field has a default value and no validation rule, it may seem like it’s being validated, but in reality, it’s just pre-filled. This can give a false sense of security about validation behavior.
Always inspect your errors object and test the form with missing input to ensure validation is working as intended.
Best Practices for Ensuring Proper Validation
To ensure you handle required fields correctly, follow these best practices:
- Always define your validation rules explicitly with the
registerfunction. - Avoid relying solely on HTML5 attributes unless you’re using native validation mode.
- Use the
formState.errorsobject to check which fields have issues and display error messages accordingly. - If your form is complex, consider using
yuporzodfor schema-based validation withresolver, which integrates seamlessly with React Hook Form. - Test your form manually by submitting empty inputs to see if validation triggers.
Proper validation is crucial not just for functionality, but for UX and data integrity. With React Hook Form, you’re given the tools to handle this well—you just need to be intentional in applying them.
Final Thoughts
React Hook Form doesn’t automatically make fields optional, but it does treat them as optional unless you declare them as required. This design is great for flexibility but requires developers to be aware of the need for explicit rules.
If you’re building professional-grade applications where validation is critical, understanding this behavior is essential. You don’t want users submitting forms without mandatory information simply because the validation rule was never set.
For more deep-dives into React Hook Form and front-end best practices, check out Aaskfullstack and Wwebhub, two valuable resources that consistently provide clear, practical content for modern developers.