用于将变量添加到会话和数据库的按钮

Question

好吧，我对这一切都很陌生，所以这可能看起来是一个冗长的方法。我想做的是对于一个按钮，它只是将变量（这是一个 id）添加到会话中。这是用户在站点中可以访问的临时列表。我通过 POST 提交来做到这一点。我将这个特殊按钮称为黑板。另一个按钮是收藏夹。用户可以单击并将ID添加到他们的收藏夹（存储在数据库中），这样当他们返回并登录时，收藏夹仍然在那里。同样，这是使用 POST 提交。我的方法似乎不稳定，并且在最新版本的 Firefox (4.01) 中突然停止工作。理想情况下，我会有一个不提交的按钮（这会导致页面重新加载），但有一个在 onclick 上更改但在后台执行所有操作的实时按钮

/////Chalkboard///// (adding/removing to session)
<?php
if(isset($_POST['chalkboard_submit'])){
    $_SESSION['chalkboard'][] = $_POST['cb'];
}
elseif(isset($_POST['chalkboard_remove'])){
    $_SESSION['chalkboard'] = array_diff($_SESSION['chalkboard'], array($_POST['cb']));
}

/////Favorites///// (adding/removing to database)
if(isset($_POST['favorites_submit'])){
    $fav_query = "SELECT favorites FROM users
                    WHERE id = {$_SESSION['id']}";
    $fav_result = mysql_query($fav_query,$connection);
    $row = mysql_fetch_array($fav_result);
    if(empty($row['favorites'])){
        $favorites = array();
        $favorites[] = $_POST['fav'];
        $_SESSION['favorites'] = $favorites;
        $favorites = __serialize($favorites);
    }elseif(!empty($row['favorites'])){
        $favorites = __unserialize($row['favorites']);
        if(!in_array(($_POST['fav']), $favorites)){
            $favorites[] = $_POST['fav'];}
        $_SESSION['favorites'] = $favorites;
        $favorites = __serialize($favorites);
    }
    $fav_insert = "UPDATE users SET
                    favorites = '{$favorites}'
                    WHERE id = '{$_SESSION['id']}'
                    LIMIT 1
                    ";
    $fav_result = mysql_query($fav_insert,$connection);     
}
elseif(isset($_POST['favorites_remove'])){
    $fav_query = "SELECT favorites FROM users
                    WHERE id = {$_SESSION['id']}";
    $fav_result = mysql_query($fav_query,$connection);
    $fav_row = mysql_fetch_array($fav_result);
        $favorites = __unserialize($fav_row['favorites']);
        $favorites = array_diff($_SESSION['favorites'], array($_POST['fav']));
        $_SESSION['favorites'] = $favorites;
        $favorites = __serialize($favorites);
    $fav_insert = "UPDATE users SET
                    favorites = '{$favorites}'
                    WHERE id = '{$_SESSION['id']}'
                    LIMIT 1
                    ";
    $fav_result = mysql_query($fav_insert,$connection);
}

?>
///////// FORM ///////////
<?php
$quote = "<a name=\"" . $quotes['id'] . "\"></a>
                <form action=\"favorites.php?subj=" . $_SESSION['subj'] . "#" . $quotes['id'] . "\" method=\"post\">
                <a href=\"quote_details.php?id=" . $quotes['id'] . "\">\"" . $quotes['quote'] . "\"</a>
                <input type=\"hidden\" value=\"" . $quotes['id'] . "\" name=\"cb\" />
                <input type=\"hidden\" value=\"" . $quotes['id'] . "\" name=\"fav\" />";

                ###################### CHALK-BOARD #################################

                if(isset($_SESSION['chalkboard']) && in_array($quotes['id'], $_SESSION['chalkboard'])){
                    $quote .= "<input type=\"image\" src=\"images/chalk_board_add_active.gif\" name=\"chalkboard_remove\" value=\"submit\" title=\"Remove from Chalk-board\"/>";
                }else{
                    $quote .= "<input type=\"image\" src=\"images/chalkboard_add.gif\" name=\"chalkboard_submit\" value=\"submit\" title=\"Add to Chalk-board\"/>";
                }

                ####################### FAVORITES ################################

                if(isset($_SESSION['favorites']) && in_array($quotes['id'], $_SESSION['favorites'])){
                    $quote .= "&nbsp;&nbsp;<input type=\"image\" src=\"images/favorites_hover.gif\" name=\"favorites_remove\" value=\"submit\" title=\"Remove from Favorites\"/>";
                }else{
                    $quote .= "&nbsp;&nbsp;<input type=\"image\" src=\"images/favorites_add.gif\" name=\"favorites_submit\" value=\"submit\" title=\"Add to Favorites\"/>";
                }
$quote .= "</form>";
?>

Answer 1

当使用图像作为提交按钮时，浏览器通常会发送您单击图像的位置，而不是发送图像是否被单击。浏览器不会发送 chalkboard_submit=submit，而是发送 chalkboard_submit_x=20 和 chalkboard_submit_y=15（这些数字将根据用户所在位置的不同而有所不同）单击图像）。

某些浏览器可能仍仅发送 chalkboard_submit=submit，而其他浏览器将发送所有三个。要解决此问题并保持与大多数浏览器的兼容性，您需要检查这两种方式。将：

if(isset($_POST['chalkboard_submit'])){
    $_SESSION['chalkboard'][] = $_POST['cb'];
}
elseif(isset($_POST['chalkboard_remove'])){
    $_SESSION['chalkboard'] = array_diff($_SESSION['chalkboard'], array($_POST['cb']));
}

if(isset($_POST['favorites_submit'])){

elseif(isset($_POST['favorites_remove'])){

更改为：

if(isset($_POST['chalkboard_submit']) || isset($_POST['chalkboard_submit_x'])){
    $_SESSION['chalkboard'][] = $_POST['cb'];
}
elseif(isset($_POST['chalkboard_remove']) || isset($_POST['chalkboard_remove_x'])){
    $_SESSION['chalkboard'] = array_diff($_SESSION['chalkboard'], array($_POST['cb']));
}

if (isset($_POST['favorites_submit']) || isset($_POST['favorites_submit_x'])){

elseif(isset($_POST['favorites_remove']) || isset($_POST['favorites_remove_x'])){
它应该有效。

您无需检查 _x' 和 _y' 是否都已设置，因为如果其中一个设置，则另一个也必须设置。