gistfile1.php

<?php

/* This actually all looks fine and shouldn't be problematic really.  I'd do a few things differently, most likely, but mostly because I'd envision it within the WordPress context. */
function get_list_view_html( $product_id, $product ) {
    $products = get_products_all();
    $output = "";

    $output = $output . "<li>";
    $output = $output . '<a href="shirt.php?id=' . $product_id . '">';
    $output = $output . '<img src="' . $product["img"] . '" alt="' . $product["name"] . '">';          
    $output = $output . "<p>View Details</p>";
    $output = $output . "</a>"
    $output = $output . "</li>";

    return $output;
}



// This is what I did to add the dropdown and submit button. some lines are commented out as I was messing around.

function get_list_view_html($product_id, $product){
    $products = get_products_all();
    $output   = "";

    $output = $output . "<li>";
    $output = $output . '<a href="shirt.php?id=' . $product_id . '">';
    $output = $output . '<img src="' . $product["img"] . '" alt="' . $product["name"] . '">';          
    $output = $output . "<p>View Details</p>";
    $output = $output . "</a>";
    
    /* All good so far */
    /* Worth noting that, rather than "$output = $output . whatever", you can actually just do $output .= $whatever */
    /* The ".=" is the same as $output = $output . $whatever.   */
    
    $output = $output . '<form target="paypal" action="https://www.paypal.com/cgi-bin/webscr" method="post">';
    $output = $output . '<input type="hidden" name="cmd" value="_s-xclick">';
    $output = $output . '<input type="hidden" name="hosted_button_id" value="<?php echo $product["paypal"]; ?>">';
    $output = $output . '<input type="hidden" name="item_name" value="<?php echo $product["name"]; ?>">';
    $output = $output . '<input type="hidden" name="on0" value="Size">';
    
    /* Really shouldn't ever be using tables for anything other than tabular data, so I'm removing the commented out tables. */
    
    $output = $output . '<label for="os0">Size</label>';
    $output = $output . '<select name="os0" id="os0">';
    
    /* This is where things fall apart.  You have PHP expressions within a string ('') */
    /* I'll comment out what you had, and paste in what it should be. */
    //$output = $output . '<?php foreach($product["sizes"] as $size) { ;
    //$output = $output . '<option value="<?php echo $size;"><?php echo $size></option>';
    //$output = $output . '<?php } ';
    
    foreach ( $product["sizes"] as $size ) { 
        $output .= '<option value="' . $size; . '">' . $size . '</option>';
    }
    
    $output .= '</select>';
    
    $output = $output . '<input type="submit" value="Add to Cart" name="submit" id="small_submit">';
    $output = $output . '</form>';
    $output = $output . "</li>";

    return $output;
}