CODEWITHSUNDEEP
phpformsvalidationsession
JimB814
JimB814

Reputation: 512

Stop empty field from submitting

Need to stop empty field from submitting and display error message on the same page.

I would appreciate any assistance. Here's the entire shopping cart code. Part in question between lines of asterisks. Thanks!

// If no cart exists, create $_SESSION['cart'] array 
if(!isset($_SESSION['cart'])){
    $_SESSION['cart'] = array();
}

// Add item to array
if(isset($_POST['action']) && $_POST['action'] === 'add'){

/*******************************************************/    
    // Check if input is empty / null
    if(($_POST['id']) == ''){
        $error = '*Please enter an ID number.';
        include 'error.html.php';
        exit();
    }
/*******************************************************/ 

    // Check if form data exists
    if(isset($_POST['id'])){
        $id = $_POST['id'];
    }

    // Check if ID already in cart
    if(isset($_SESSION['cart'][$id])){
        $error = '*Item already in cart.';
    }

    // Add new ID to array (hard-code some data for test file)
    $newitem = array(     
        'id' =>  $id,
        'part_number' =>  '369A7170-11',
        'quantity' =>  '1'
    );

    // Add new data to cart with ID as key    
    $_SESSION['cart'][$id] = $newitem;  
}    

// Remove item from array
if(isset($_POST['action']) && $_POST['action'] === 'remove'){

    // Check if form data exists
    if(isset($_POST['id'])){
        $id = $_POST['id'];
    }

    unset($_SESSION['cart'][$id]);
}

// Empty cart
if(isset($_POST['action']) && $_POST['action'] === 'empty'){
    unset($_SESSION['cart']);
}

// Initialize $count variable; get item count
$count = '';
if(isset($_SESSION['cart'])) $count = count($_SESSION['cart']);

// Display results
if(isset($_SESSION['cart'])){
    $show_cart = var_dump($_SESSION['cart']);
    echo $show_cart;
}


/************** TEST ******************************/
//$_SESSION['quantity'][$id] = $quantity;
if(isset($_SESSION['cart'])) echo 'ID: '  . $_SESSION['cart'][$_POST['id']]['id'] . '<br>';
if(isset($_SESSION['cart'])) echo 'Qty: ' . $_SESSION['cart'][$_POST['id']]['quantity'] . '<br>';
$new_quantity = 5;
if(isset($_SESSION['cart'])) $_SESSION['cart'][$_POST['id']]['quantity'] = $new_quantity;
if(isset($_SESSION['cart'])) echo 'Updated Qty: ' . $_SESSION['cart'][$_POST['id']]['quantity']; 
/************** // END TEST ***********************/

?><!DOCTYPE hml>
<html lang="en">
    <head>
        <meta charset="utf-8">
        <title>Cart</title>
    </head>
<body>
    <h3>Cart Management</h3>
    <p style="color:#ff0000;"><?php if(isset($error)) echo htmlentities($error, ENT_QUOTES); ?></p>
    <p>Items in cart: <?php if(isset($count) && $count > 0)echo htmlentities($count, ENT_QUOTES); else echo 'none'; ?></p>
    <form action="" method="post">
        <label for="id">ID:</label>
        <input type="text" name="id" id="id" autofocus>
        <input type="hidden" name="action" value="add">
        <input type="submit" value="Add">
    </form>

    <form action="" method="post">
        <label for="id">By ID:</label>
        <select name="id" id="id">
            <option value="">Select ID</option>
            <?php foreach($_SESSION['cart'] as $key => $item): ?>
            <option value="<?php echo htmlentities($item['id'], ENT_QUOTES); ?>"><?php echo htmlentities($item['id'], ENT_QUOTES); ?></option>            
            <?php endforeach; ?>
        </select>     
        <input type="hidden" name="action" value="remove">
        <input type="submit" value="Remove"> 
    </form>

    <form action="" method="post">
        <input type="hidden" name="action" value="empty">
        <input onclick="return confirm('Are you sure you want to empty the cart?');" type="submit" value="Empty cart"> 
    </form>
</body>
</html>

Upvotes: 0

Views: 921

Answers (2)

J. Han
J. Han

Reputation: 122

$_POST['id'] will always be set if it's on your form and it is submitted, regardless if it's empty or not. If you want to check if it's empty, then use

    if(empty($_POST['id'])){
        // give error
    }
    else{
        // do something on success
    }

Alternatively, you could set the input field to be required in the html code. Doing so will make it so the form will not be submitted unless that field has an input.

Try this:

if(isset($_POST['action']) && $_POST['action'] === 'add'){

/*******************************************************/    
// Check if input is empty / null
if(empty($_POST['id'])){
    $error = '*Please enter an ID number.';
}
else{
/*******************************************************/ 

    // Check if form data exists
    if(isset($_POST['id'])){
        $id = $_POST['id'];
    }

    // Check if ID already in cart
    if(isset($_SESSION['cart'][$id])){
        $error = '*Item already in cart.';
    }

    // Add new ID to array (hard-code some data for test file)
    $newitem = array(     
        'id' =>  $id,
        'part_number' =>  '369A7170-11',
        'quantity' =>  '1'
    );

// Add new data to cart with ID as key    
        $_SESSION['cart'][$id] = $newitem;  
    }
}

Upvotes: 2

Erik Flitman
Erik Flitman

Reputation: 163

Use the following syntax instead and it should work.

if(!$_POST['id']){ 
    code....
}

Upvotes: 0

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