How to add an image to cart in Wordpress (without plugins)?

Question

Sessions

Please help me add an image to the cart in Wordpress using the POST method. Perhaps I am "reinventing the wheel", but still I want to solve this problem in principle.

On each page, the image is retrieved from the post through the ID of the post itself:

<?php
                session_start();
                    // Получим ID вложения поста
                    //$id = the_id();
                    $attachment_image = get_children( array(
                    	//'numberposts' => 3,
                    	'post_mime_type' => 'image',
                    	'post_parent' => $id,
                    	'post_type' => 'attachment'
                    ) );
                    // вынимаем первую картинку из массива
                    $attachment_image = array_shift($attachment_image);
                    $img = '<img src="'.wp_get_attachment_url( $attachment_image->ID).'" height="" width="150" alt=""/>';
                    $_SESSION['img'] = $img;
?>

Further, on the same page, we send it for processing to the cart.php file:

<form method="post" class="addtocart" action=".../cart.php">
                    Цена товара: <?=$_SESSION['price']." за 1 единицу"?><br/>
                    Изображение: <label for="picture"><?=$_SESSION['img']?></label>
                    Наименование: <input name="item" type="text" size="14"/><br/>
                    Кол-во товара: <input name="count" type="text" size="14"/><br/>
                    Добавить товар: <button type="submit" value="Добавить">Add</button>
</form>

In the same file (cart.php) we display the received data. Everything is output except for the image thumbnail.

<?PHP
        session_start();
        // Название товара
        $_SESSION['item'] = $_POST['item'];
        // Кол-во товара
        $_SESSION['count'] = $_POST['count'];
        // Цена товара
        $_SESSION['price'] = 100;
        // 
        $_SESSION['img'] = $_POST['picture'];

    
        // if(isset($_SESSION['item']) and is_numeric($_SESSION['count'])){
            echo $_SESSION['item']."<br/>";
            echo "Вы добавили товар в карзину!<br/>";
            echo "Его кол-во ".$_SESSION['count']."<br/>";
            echo "Вы должны заплатить: ".$_SESSION['count'] * $_SESSION['price']." рублей";
            echo $_SESSION['img'];
        // }
?>

Thank you in advance for your help

Answer 1

First, do it humanly - pass the id of the picture, and in the basket already get its url by id.
Well, check what data you have is transmitted, perhaps they simply do not exist.

Answer 2

I agree, everything has changed. Got result
Sending to cart:

<?php
session_start();
$_SESSION['id'] = $id;
?>

<form name="addtocart" id="addtocart" class="addtocart" method="post">
<input type="hidden" name="id" value="<?=the_id()?>"/>
<button type="submit" value="Добавить" class="img_bottom order" id="order"><p>Добавить<br>в избранное</p></button>
</form>

Output in modal window:

<?php
            session_start();
            $_SESSION['id'] = $_POST['id']; // ID image
            $id = $_POST['id'];
            echo "Изображение добавлено!<br/><br/>";

    	    // Получим ID вложения поста 5
            $id = $_POST['id'];
            $attachment_image = get_children( array(
            	'numberposts' => 3,
            	'post_mime_type' => 'image',
            	'post_parent' => $id,
            	'post_type' => 'attachment'
            ) );
            // вынимаем первую картинку из массива
            $attachment_image = array_shift($attachment_image);
            $img = '<img src="' . wp_get_attachment_url( $attachment_image->ID).'" height="" width="150" alt=""/>';
            echo $img;
      ?>

Now it remains to figure out how to add multiple images. Now one is added and it is updated when a new one is added.