使用PHP将HTML值传递给url

Question

I am fairly new to PHP and Javascript programming. Currently I am working on a checkout component for an ecommerce website. I have an amount value for a product that is inside a span element and it's changing value according to the quantity the user selects. I need to grab these two values (quantity and value) and pass them to another PHP page. What's the best approach for doing this?

</div> <!-- slider-nav.// -->
    </article> <!-- gallery-wrap .end// -->
        </aside>
        <aside class="col-sm-7">
    <article class="p-5">
    <h3 class="title mb-3" id="product-title">Colocar o nome do produto </h3>

<div class="mb-3"> 
    <var class="price h3 text-warning"> 
        <span class="currency">EU €</span><span class="num" id="big_valor">29.99</span>
    </var> 

</div> <!-- price-detail-wrap .// -->
<dl>
  <dt>Descrição</dt>
  <dd><p>Here goes description consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco </p></dd>
</dl>
<dl class="row">
  <dt class="col-sm-3">Modelo</dt>
  <dd class="col-sm-9">12345611</dd>

  <dt class="col-sm-3">Cor</dt>
  <dd class="col-sm-9">Azul e Branco </dd>

  <dt class="col-sm-3">Entrega</dt>
  <dd class="col-sm-9">Portugal e Espanha</dd>
</dl>

<hr>
    <div class="row">
        <div class="col-sm-5">
            <dl class="dlist-inline">
              <dt>Quantidade: </dt>
              <dd> 
                <select class="form-control form-control-sm" style="width:70px;" onchange="calcular();" id="selector">
                    <option> 1 </option>
                    <option> 2 </option>
                    <option> 3 </option>
                </select>
              </dd>
            </dl>  <!-- item-property .// -->
        </div> <!-- col.// -->

    </div> <!-- row.// -->
    <hr>
    <a href="customer_order_form.php" class="btn  btn-primary" click="sendInfo();"> Comprar </a>

</article> <!-- card-body.// -->
        </aside> <!-- col.// -->
    </div> <!-- row.// -->
</div> <!-- card.// -->
</div>
</div>

Javascript:

$(document).ready(function() {
    $(".item-gallery a").fancybox({
        'transitionIn'  :   'elastic',
        'transitionOut' :   'elastic',
        'speedIn'   :   800, 
        'speedOut'  :   200, 
        'overlayShow'   :   false,
        'cyclic'    :   true,


    }).click(function(e){
        var image_name = $(this).attr('href');  $(".img-big-wrap div a img").attr('src',image_name);

    })

}); //END OF DOCUMENT READY

function calcular(){

let select_value = document.getElementById("selector").value;
let amount = select_value*29.99;
$('#big_valor').html(amount);
}

Answer 1

You can send quantity and value to PHP and save it in a session. Then you first look for these 2 values in the session and if you won't find them then quantity and value will be your default values.

Edit: I recommend you to send only quantity to PHP and calculate the price based on the product price you have in your database. If you send the price from your frontend and then you use it in your order, user may change the product price and you don't want that.