Adding input element dynamically to form and storing the value in database

Question

I have to make a form which creates a button, clicking upon which a dynamic text field appears.

My javascript for this is:

function add() {

    //Create an input type dynamically.
    var element = document.createElement("input");
    element.style.borderRadius ="5px";
    //Assign different attributes to the element.
    element.setAttribute("type", "text");
    element.setAttribute("value", "ip2");
    element.setAttribute("name", "ip2");
    element.setAttribute("placeholder", "ip2"); 
    element.setAttribute("required", "true");
    var foo = document.getElementById("fooBar");

    //Append the element in page (in span).
    foo.appendChild(element);

}

and I am using following code for the button and required container:

<form method="post" action="insert.php">
<INPUT type="button" value="Add" onclick="add(document.forms[0].element.value)"/>

<span id="fooBar"></span>
</form>

Input field is fine. I only want to know how to take value from the dynamic input field and store it in the db.

Thanks in advance

Answer 1

Once the fiels is addedd to fooBar, it is inside the form. If you submit the form via a submit button (see below HTML code) or via javascript document.getElementById("myForm").submit(); you have to handle the results sent to the server with a script on the server, eg with PHP.

echo '<pre>';
print_r( $_POST ); /* Show ALL given $_POST input */
echo '</pre>';
error_reporting(0);
$conn = mysqli_connect("localhost","root","","pnb");
if( !$conn ) {
    die('Could not connect to MySQL: ' . mysqli_error() );
}

if( isset( $_POST['ip2'] ) AND !empty( $_POST['ip2'] ) ) {
    $ip2 = $_POST['ip2'];
    mysqli_query( $conn, 'INSERT INTO records (ip) VALUES ("' . mysqli_real_escape_string( $conn, $ip2 ) . '")' );
    echo 'Row added!';
}
mysqli_close( $conn );

HTML code:

<form method="post" action="insert.php">
    <input type="button" value="Add" onclick="add()"/>
    <input type="submit" value="submit" />
    <span id="fooBar"></span>
</form>
<script type="text/javascript">
function add() {

    //Create an input type dynamically.
    var element = document.createElement("input");
    element.style.borderRadius ="5px";
    //Assign different attributes to the element.
    element.setAttribute("type", "text");
    element.setAttribute("value", "ip2");
    element.setAttribute("name", "ip2");
    element.setAttribute("placeholder", "ip2"); 
    element.setAttribute("required", "true");
    var foo = document.getElementById("fooBar");

    //Append the element in page (in span).
    foo.appendChild(element);
}
</script>

Note: document.forms[0].element.value does not exist, hence I removed it from the code above. Also I added a submit button, to submit the form to the insert.php script on the server.

The above script will check if a post package with the name "ip2" is received. It than will setup a MySQLi connection to a database and insert the value in table "tablename". The above code should be placed in insert.php

Answer 2

PHP:

if(isset($_POST['foo'])) {

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 

$item = $_POST['foo']

$sql = "INSERT INTO thetable (item)
VALUES ('$item')";

if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();

}
?>

HTML:

<form action="" method="post">
    <input type="text" name="foo" value="foo">
    <input type="submit" value="Submit">
</form>

Also if you are targeting an external file you should update the action attr on the form to the url of the file eg action="target.php"