Web Development

<br />
<?php<br />
  /* e-cart related functions */<br />
	  function does_ecart_exist()<br />
	  {<br />
		    // if 'ecart' session variable is set, it exists<br />
		    return (isset($_SESSION['ecart']));<br />
	  }<br />
<br />
  function is_item_in_ecart($product_id)<br />
  {<br />
		    // make sure the e-cart exists!<br />
		    if (!does_ecart_exist())<br />
			      return (false);<br />
<br />
		    return (isset($_SESSION['ecart'][$product_id]));<br />
  }<br />
<br />
  function add_item_to_ecart($product_id, $product_name, $unit_price, $quantity)<br />
  {<br />
    // make sure the e-cart exists!<br />
    if (!does_ecart_exist())<br />
      return (false);<br />
<br />
    // todo: determine what to do if item already in cart...<br />
    // if (is_item_in_ecart($product_id))<br />
    // update or return error?<br />
<br />
    // create an array to hold the product data<br />
    $product_data = array('name' => $product_name, 'price' => $unit_price, 'quantity' => $quantity);<br />
<br />
    // add the product to the e-cart array, using it's id as the key<br />
    $_SESSION['ecart'][$product_id] = $product_data;<br />
<br />
    return (true);<br />
  }<br />
<br />
  function view_ecart_contents()<br />
  {<br />
    // make sure the e-cart exists!<br />
    if (!does_ecart_exist())<br />
      return (false);<br />
<br />
    // grab each item in the cart, and print out data<br />
    $product_id = 0;<br />
    $product_data = array();<br />
		<br />
    while (list($product_id, $product_data) = each($_SESSION['ecart']))<br />
    {<br />
      printf('Product Id: %1$s, Name: %2$s, Price: %3$s, Quantity: %4$s', <br />
        $product_id,<br />
        $product_data['name'],<br />
        $product_data['price'],<br />
        $product_data['quantity']);<br />
    }<br />
<br />
    return (true);<br />
  }<br />
<br />
  function remove_item_from_ecart($product_id)<br />
  {<br />
    // make sure the e-cart exists!<br />
    if (!does_ecart_exist())<br />
      return (false);<br />
<br />
    // item must be in ecart<br />
    if (!is_item_in_ecart($product_id))<br />
      return (false);<br />
<br />
    // remove the product from the ecart<br />
    // this code may need fixing, but I think it should work<br />
    // all you're doing is removing an item from the ecart array<br />
    $_SESSION['ecart'][$product_id] = array();<br />
		    unset($_SESSION['ecart'][$product_id]);<br />
	<br />
    return (true);<br />
  }<br />
<br />
  function check_out_ecart()<br />
  {<br />
    // here take the e-cart session data, perform any validation, then add <br />
    // a record to the order table<br />
  }<br />
<br />
  /* The following code will be executed by each .php file that includes this file */<br />
  // must call session_start before you can access any session data<br />
  session_start();<br />
<br />
  // if cart hasn't been created for user yet, create one now (an empty array)<br />
  // this code will trigger when the user 1st visits the site<br />
  if (!is_ecart_exists())<br />
    $_SESSION['ecart'] = array();<br />
?><br />
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