Form Validation not working in Blazor 3.1

When working with forms in Blazor 3.1, you might encounter an issue where form validation doesn't seem to be working as expected. This can be frustrating, especially if you're not sure what's causing the problem.

In this blog post, we'll explore some common reasons why form validation might not be working in Blazor 3.1 and provide solutions to help you resolve these issues.

Incorrect Input Type

One common mistake that can lead to form validation not working is using an incorrect input type. By default, Blazor uses client-side validation, which means that the browser checks the validity of the input before submitting the form. However, certain input types are not supported by client-side validation. For instance, if you use a button input type instead of a submit input type, the form validation won't work as expected.

To resolve this issue, ensure you use the correct input type for your form elements. For buttons that submit forms, use the submit input type.

Incorrect: <input type="button" class="btn btn-primary" value="Save" /> Correct: <input type="submit" class="btn btn-primary" value="Save" />

Invalid OnSubmit Handler

Another potential cause of form validation not working in Blazor 3.1 is using an invalid OnSubmit handler. The OnSubmit handler is responsible for handling the submission of the form and triggering the validation process. If you specify an incorrect or missing OnSubmit handler, the form validation won't be triggered.

To resolve this issue, ensure you specify the correct OnSubmit handler for your form. The OnSubmit handler should be a method in your code that handles the form submission and validation.

Incorrect: <form OnSubmit="@OnCreate"> Correct: <form OnValidSubmit="@OnCreate">

Additional Validation Attributes

In addition to using the correct input type and OnSubmit handler, there are other validation attributes that you can use to enhance the validation of your Blazor forms. These attributes include:

• required: Indicates that the field is required and cannot be empty.
• minlength and maxlength: Specify the minimum and maximum lengths for text input fields.
• pattern: Specifies a regular expression that the input value must match.
• email: Validates that the input value is a valid email address.
• url: Validates that the input value is a valid URL.

Using these validation attributes can help you enforce additional validation rules on your form fields and improve the overall user experience.

In conclusion, if you're experiencing issues with form validation not working in Blazor 3.1, it's important to check the input type, OnSubmit handler, and any additional validation attributes you're using. By ensuring that these elements are configured correctly, you can resolve the validation issues and improve the functionality of your Blazor forms.