Error in form validation

Question

What I need to do is when the email is not valid send from the javascript alert wanted to show a message above the form in question that showed the email was invalid!

HTML CODE

           <input type="email" class="form-control" name="email" id="email" 
   placeholder="Email" data-rule="email" data-msg="Introduza um email 
 válido"REQUIRED />

          <div class="validation"></div>
        </div>

PHP validation

 if(isset($_POST["contact"]))
  {

 if (filter_var($email, FILTER_VALIDATE_EMAIL)) {

 $novocontacto = "insert into contacto(nomecompleto, email, assunto, 
  mensagem) VALUES ('$nomecomp', '$email', '$assunto' , '$mensagem')";
 $novocontacto_run = mysqli_query($conn,$novocontacto);

 echo 
'<script type="text/javascript">alert("Mensagem enviada com sucesso!") 
 </script>';
  }

  else 
 {
 echo '<script type="text/javascript">alert("Email inválido")</script>';
  }

    }

Answer 1

The best option would be to use the .validate a jquery plugin as mentioned above, this plugin allows you to specify a set of rules for the content validation messages and validation in real time, this example illustrates this well.

You can set the . validate to send your form by ajax if everything is correct.

Answer 2

Hello, one possible solution without restructuring all the code is to add a div on top of the form and php return the script by adding the message.

html code

// ...
<div class="mensagem"></div>
// formulário
// ...

php validation

 echo '<script type="text/javascript">document.querySelector(".mensagem").innerHTML = "email inválido"; </script>';