Question

i have a submit page in html. when i submit the form data, it goes to a php page, which inserts the data in the database.

my question is how would i ensure that the data on the html page is not null or empty without using javascript? is there anyway this could be done in php? thanks!

Answer 1

Simply use control structures as usual:

$non_empties = array('name', 'email', 'address');

foreach ($non_empties as $field) {
    if (! isset($_POST[$field]) || $_POST[$field] == '') {
        show_error("Please fill your $field, thank you.");
    }
}

$db->insert();

More advanced example:

// Defined in your library
function validate_as_non_empty(Array $non_empties) {
    foreach ($non_empties as $field) {
        if (! isset($_POST[$field]) || $_POST[$field] == '') {
            throw new Exception("Please fill your $field, thank you.");
        }
    }
}

// Defined in your library
function validate_as_foo(Array $arr) { ... }

// Your request handler
try {
    validate_as_non_empty(array('name', 'address'));
    validate_as_foo(array('email'));
    $db->insert();
} catch (Exception $e) {
    show_error($e->getMessage());
}

There are at least million ways to do validation. Usually you have some kind of framework to rely on. The above examples are merely given for inspiration.