Custom validation needs to notify users in an accessible way as described in the User Notifications part of this tutorial.Client-side validation alone does not ensure security; therefore data needs to be validated on the server-side as well.Forms frequently include required input that needs to be clearly identified using labels.
HTML5 defines a range of built-in functionality to validate common types of input, such as email addresses and dates.
In some situations, such as validating custom controls or supporting legacy browsers, additional scripting may be necessary to validate user input.
There are exceptions to every rule, but now that you know what’s possible and how things are commonly utilized, you have the knowledge to take that and apply it to your own specific project.
If you have suggestions or questions, feel free to leave comments below.
The “validation descriptor” is a string specifying the type of validation to be performed.