You can build applications which perform ajax calls to upload data to the server behind the scenes in response to user actions, you can validate user input and apply multiple validation rules to a single input, you can even create your own custom validators. Things to notice is the 'enctype' attribute with a value of 'multipart/form-data'.This is necessary in order to correctly encode the form data.Validation also only occurs on form submission and we may wish instead to validate the form on key input or on when the user exits a field.
The pattern attribute works with the following input types: text, search, url, tel, email, and password.
Tip: Use the global title attribute to describe the pattern to help the user.
The formtarget attribute specifies a name or a keyword that indicates where to display the response that is received after submitting the form.
The formtarget attribute overrides the target attribute of the element's value is checked against.
Let's say that I have a form with three inputs: name and email as text input fields and one attachment as file input.
After validation-success eform can move them to the target-folder.
On validation errors, the field will be empty, because there is no way that field can be filled programmatically.
The maxlength attribute does not provide any feedback.
If you want to alert the user, you must write Java Script code.
Validation is provided via the 'required' attribute.