多语言环境下PHP时间戳转相对时间的变量传递问题解决

我正在做一个多语言场景的功能，需要写个PHP函数把MySQL时间戳转换成「几天前、一天前」这类相对时间描述。一开始写的函数是这样的：

function time_ago($timestamp, $lang) { 
    $time_ago = strtotime($timestamp); 
    $current_time = time(); 
    $time_difference = $current_time - $time_ago; 
    $seconds = $time_difference; 
    $minutes = round($seconds / 60); 
    $hours = round($seconds / 3600); 
    $days = round($seconds / 86400); 
    $weeks = round($seconds / 604800); 
    $months = round($seconds / 2629440); 
    $years = round($seconds / 31553280); 

    if ($seconds <= 60){ 
        return $lang['time_just_now']; 
    } else if ($minutes <= 60){ 
        if ($minutes == 1){ 
            return $lang['time_one_minute_ago']; 
        } else { 
            return $lang['time_minutes_ago']; 
        } 
    } else if ($hours <= 24){ 
        if ($hours == 1){ 
            return $lang['time_one_hour_ago']; 
        } else { 
            return $lang['time_hours_ago']; 
        } 
    } else if ($days <= 7){ 
        if ($days == 1){ 
            return $lang['time_one_day_ago']; 
        } else { 
            return $lang['time_days_ago']; 
        } 
    } elseif($weeks <= 4.3) { 
        if ($weeks == 1) { 
            return $lang['time_one_week_ago']; 
        } else { 
            return $lang['time_weeks_ago']; 
        } 
    } elseif($months <= 12) { 
        if ($months == 1) { 
            return $lang['time_one_month_ago']; 
        } else { 
            return $lang['time_months_ago']; 
        } 
    } else { 
        if ($years == 1) { 
            return $lang['time_one_year_ago']; 
        } else { 
            return $lang['time_years_ago']; 
        } 
    } 
}

我的多语言系统是基于会话的，所有语言字符串都存在$lang数组里，比如西班牙语的配置是这样的：

$lang['time_one_day_ago'] = 'hace un día'; 
$lang['time_days_ago'] = "hace {$days} días"; 

但这里有个问题：我没法把函数里计算出来的$days变量传递给$lang数组里的字符串模板，该怎么解决呢？

解决方案 #

后来参考了思路，调整了函数实现，同时修改了语言文件的写法，现在可以正常传递变量了：

修改后的函数 #

function time_ago($timestamp) { 
    global $lang; 
    $time_ago = strtotime($timestamp); 
    $current_time = time(); 
    $time_difference = $current_time - $time_ago; 
    $seconds = $time_difference; 
    $minutes = round($seconds / 60); 
    $hours = round($seconds / 3600); 
    $days = round($seconds / 86400); 
    $weeks = round($seconds / 604800); 
    $months = round($seconds / 2629440); 
    $years = round($seconds / 31553280); 

    if ($seconds <= 60){ 
        return $lang['time_just_now']; 
    } else if ($minutes <= 60) { 
        if ($minutes == 1){ 
            return $lang['time_one_minute_ago']; 
        } else { 
            return sprintf(_($lang['time_minutes_ago']), $minutes); 
        } 
    } else if ($hours <= 24){ 
        if ($hours == 1){ 
            return $lang['time_one_hour_ago']; 
        } else { 
            return sprintf(_($lang['time_hours_ago']), $hours); 
        } 
    } else if ($days <= 7){ 
        if ($days == 1){ 
            return $lang['time_one_day_ago']; 
        } else { 
            return sprintf(_($lang['time_days_ago']), $days); 
        } 
    } elseif($weeks <= 4.3) { 
        if ($weeks == 1) { 
            return $lang['time_one_week_ago']; 
        } else { 
            return sprintf(_($lang['time_weeks_ago']), $weeks); 
        } 
    } elseif($months <= 12) { 
        if ($months == 1) { 
            return $lang['time_one_month_ago']; 
        } else { 
            return sprintf(_($lang['time_months_ago']), $months); 
        } 
    } else { 
        if ($years == 1) { 
            return $lang['time_one_year_ago']; 
        } else { 
            return sprintf(_($lang['time_years_ago']), $years); 
        } 
    } 
}

对应语言文件的写法 #

把原来的变量嵌入改成占位符%s，这样就能通过sprintf传递函数里计算出的数值了：

$lang['time_one_year_ago'] = 'hace un año'; 
$lang['time_years_ago'] = 'hace %s años'; 

感谢arkadianriver提供的思路！

内容的提问来源于stack exchange，提问作者Derian Andrés