php - Laravel/Carbon 中的多时区

Question

我想知道这是否可能，所以假设我有一个这样的模型:

MyModel
   SomeDate - Carbon

现在，我也有一个当前用户的时区，如下所示:

User
   MyTimezone

数据库中存储的时区始终以 UTC 格式存储(以确保一切一致)，输出日期应始终格式化为特定时区(但每个用户的时区不同)，例如美国/芝加哥为 User1和 America/Denver 的 User2。

有没有一种方法可以在输出之前自动将每个 Carbon 实例的时区格式化为给定的时区，或者我是否必须循环遍历集合并相应地设置每个时区？

设置 app.timezone 不起作用，因为它还会导致 Carbon 实例以 app.timezone 时区保存到数据库中，而数据库中的所有日期应该是 UTC，因此我失去了一致性。

我目前在 App 配置中将 app.timezone 设置为 UTC，但我也被迫在输出之前将所有 Carbon 实例转换为正确的时区。有没有更好的方法，也许是在 Carbon 变成字符串之前捕获执行并在那里执行？

编辑:

我尝试过的事情:

覆盖 setAttribute 和 getAttribute:

public function setAttribute($property, $value) {
    if ($value instanceof Carbon) {
        $value->timezone = 'UTC';
    }

    parent::setAttribute($property, $value);
}

public function getAttribute($key) {
    $stuff = parent::getAttribute($key);

    if ($stuff instanceof Carbon) {
        $stuff->timezone = Helper::fetchUserTimezone();
    }

    return $stuff;
}

覆盖 asDateTime:

protected function asDateTime($value)
{
    // If this value is an integer, we will assume it is a UNIX timestamp's value
    // and format a Carbon object from this timestamp. This allows flexibility
    // when defining your date fields as they might be UNIX timestamps here.
    $timezone = Helper::fetchUserTimezone();

    if (is_numeric($value))
    {
        return Carbon::createFromTimestamp($value, $timezone);
    }

    // If the value is in simply year, month, day format, we will instantiate the
    // Carbon instances from that format. Again, this provides for simple date
    // fields on the database, while still supporting Carbonized conversion.
    elseif (preg_match('/^(\d{4})-(\d{2})-(\d{2})$/', $value))
    {
        return Carbon::createFromFormat('Y-m-d', $value, $timezone)->startOfDay();
    }

    // Finally, we will just assume this date is in the format used by default on
    // the database connection and use that format to create the Carbon object
    // that is returned back out to the developers after we convert it here.
    elseif ( ! $value instanceof DateTime)
    {
        $format = $this->getDateFormat();

        return Carbon::createFromFormat($format, $value, $timezone);
    }

    return Carbon::instance($value);
}

Answer 1

我的应用程序遇到了同样的问题，远程网站将以 UTC 格式存储日期，而我必须根据登录用户显示实际日期，我想到了覆盖 Laravel Eloquent 模型。

只需扩展 Illuminate\Database\Eloquent\Model，如下所示:

<?php namespace Vendor\Package;

use Illuminate\Database\Eloquent\Model as EloquentModel;

class Model extends EloquentModel
{

    /**
    * Return a timestamp as a localized DateTime object.
    *
    * @param  mixed  $value
    * @return \Carbon\Carbon
    */
    protected function asDateTime($value)
    {
        $carbon = parent::asDateTime($value);
        // only make localized if timezone is known
        if(Auth::check() && Auth::user()->timezone)
        {
            $timezone = new DateTimeZone(Auth::user()->timezone);
            // mutates the carbon object immediately
            $carbon->setTimezone($timezone);
        }

        return $carbon;
    }
    /**
    * Convert a localized DateTime to a normalized storable string.
    *
    * @param  \DateTime|int  $value
    * @return string
    */
    public function fromDateTime($value)
    {
        $save = parent::fromDateTime($value);

        // only make localized if timezone is known
        if(Auth::check() && Auth::user()->timezone)
        {
            // the format the value is saved to
            $format = $this->getDateFormat();

            // user timezone
            $timezone = new DateTimeZone(Auth::user()->timezone);

            $carbon = Carbon::createFromFormat($format, $value, $timezone);
            // mutates the carbon object immediately
            $carbon->setTimezone(Config::get('app.timezone'));

            // now save to format
            $save = $carbon->format($format);
        }

        return $save;
    }
}

也许这对其他遇到这个问题的人有用。

作为引用

• laravel 5 (2015-03-18): Illuminate\Database\Eloquent\Model:2809-2889
• laravel 4.2 (2015-03-18): Illuminate\Database\Eloquent\Model:2583-2662