从模板执行php代码

Question

I have the following code in PHP:

if ($maintenance_mode == true)
{
    $file = 'maintenance-header.php';
    $template = file_get_contents($t_includes_path . $file);
}
else
{
    $file = 'main-header.php';
    $template = file_get_contents($t_includes_path . $file);
}

require_once($s_system_path . 'templater.php');

And then in templater.php :

$page = str_replace(array(
    '{slang}',
    '{site_title}',
    '{site_desc}',
    '{keywords}',
    '{t_assets_path}',
    '{s_assets_path}',
    '{i_assets_path}',
    ), array(
    $slang,
    $site_title,
    $site_content,
    $keywords,
    $t_assets_path,
    $s_assets_path,
    $i_assets_path,
    ),
    $template);
echo $page;

The problem is that if I try to use php code within the template file itself it doesn't get recognized and is parsed as comments/plain text. Example:

if (htmlentities($_GET['lang'], ENT_QUOTES) == 'en')
{
    echo 'English';
}
else if (htmlentities($_GET['lang'], ENT_QUOTES) == 'ru')
{
    echo 'Russian';
}
else
{
    echo 'Other';
}

How to deal with this? I really want to use {site_title} instead of <?php echo $site_title; ?> <?php echo $site_title; ?> etc. I want to keep my code as clean as possible.

Answer 1

you have to exectue your php code. if you just 'echo' it, code that is inside your string will not be executed, just printed on the page. you can use eval() function for example, but be sure that users can't force your web to eval() theirs code.. as mentioned on docs:

http://php.net/manual/en/function.eval.php