Php redirect to page if statement - php

Question

I'm trying to make you redirect to the successful page after succesfully registering but whenever I click the register button I get redirected instantly even if all the input's are empty
if(isset($_POST["registration"])){
if(!empty($_POST["gender"])
and !empty($_POST["username"])
and !strlen($_POST["username"]) < 3
and !empty($_POST["email"])
and !email($_POST["email"])
and !empty($_POST["emailver"])
and !verification($_POST["email"],$_POST["emailver"])
and !empty($_POST["password"])
and !strlen($_POST["password"]) < 8
and strlen($_POST["password"]) < 25
and checkUppercase($_POST["password"])
and checkLowercase($_POST["password"])
and checkNumber($_POST["password"])
and !empty($_POST["passwordver"])
and !verification($_POST["password"],$_POST["passwordver"])){
if(addgamer($db,$_SESSION["gender"],$_SESSION["username"],$_SESSION["email"],$_POST["password"]) === TRUE){
$url = 'succesfull.html';
header($url);
}
}
}
The function for addgamers
function addgamer($db,$gender,$username,$email,$password){
$sql = "INSERT INTO gamers (`gender`, `username`, `email`, `password`) VALUES('$gender','$username','$email','$password')";
$db -> exec($sql);
if ($db->query($sql) === TRUE) {
$GamerId = $db -> lastInsertId();
$_SESSION['GamerId'] = $GamerId;
return true;
} else {
return false;
}
}
I found some answers here but all of them do the same and I have no solution for this.
GOTO($url);
Or
header('location: $url');
Or
if(addgamer($db,$_SESSION["gender"],$_SESSION["username"],$_SESSION["email"],$_SESSION["password"]) === FALSE ){
die();
}else{
$url = 'successful.php';
header($url);
}
Also tried with jQuery
echo "<script>window.location = '$url'</script>";
On every single click on the registration submit button you get redirected to the successful page but that should not happen until everything is filled in correctly as shown from the above code.
As you can also see I'd like to fix this problem trying with php only first.

Answer 1

Validate before submitting the form would be better at first.
As #Nicolas D mentioned you should also know that the form action is the page you direct to no matter what.
You can however set this to the current page by using action="" or action="<?php echo $_SERVER['PHP_SELF']; ?>"
This last could come with exploits, you can use "htmlentities($_SERVER['PHP_SELF'])" instead. Read about this here.

Answer 2

You have a missunderstanding PHP problem.
If your form use a submit form, it will post automatically to the php page targeted.
If you don't want to post to a new page and still verify your data, then you must use ajax in jquery : http://api.jquery.com/jquery.post/ . With that you ll catch your data without unexpected redirection.
Once all your form is validated by your php code during ajax call, you can redirect in jquery on the callback function.
Hope this will help, I ve been through this step and I remember it was painful