Hello! If you are looking for guidance on how to use the :user-invalid selector in CSS to highlight user input errors, you are in the right place. This selector is utilized when the user inputs a specific value that's deemed incorrect, and we want to indicate this state visually.
:user-invalid is also applied in fields that are not traditionally accepted. For instance, when the user inputs an invalid email. Using this selector is very simple and doesn’t require you to perform JavaScript validation yourself.
To use :user-invalid, you first need to structure the HTML form correctly, then by adding styles through CSS, we can enhance the appearance of invalid fields. This method is particularly useful for places where we do not want or cannot use JavaScript.
If you are interested in a better user experience, you can use this selector to provide appropriate feedback to users or visually change the appearance of the field. For example, changing the color of an invalid field or displaying a helpful error message could assist users in easily identifying their mistakes.
In addition, with a few simple examples of this selector, we will learn how we can use it more effectively.
<form>
<label for="email">Email:</label>
<input type="email" id="email" name="email" required>
<span id="emailError"></span>
<input type="submit" value="Send">
</form>
<style>
input:user-invalid {
border-color: red;
}
#emailError {
color: red;
}
</style>
Now, let’s explain each part:
<form>
This tag starts the HTML form structure.
<label>
This tag is a label for linking the email field to the email input.
<input type="email">
This is the main input where the data must be typed, which will be outlined if there’s an error.
<span id="emailError"></span>
This is for displaying the email error message that can trigger when invalid input occurs.
input:user-invalid
This selector is used for changing the appearance of input fields that have been labeled invalid.
border-color: red;
This changes the color border of the input to red to catch the user's attention.
Now, you might be able to use these features to enhance your projects and create more professional forms.