Laravel/Carbon中的多次时间化

Question

我想知道这是否可行,所以让我说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

存储在数据库中的时区始终以UTC格式存储(以确保一切都一致),并且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America1/Chicago for User1和America /用户2的丹佛.

有没有办法在输出之前自动将每个Carbon实例的时区格式化为给定的一个,或者我是否必须遍历集合并相应地设置每个实例？

设置app.timezone不起作用,因为它还导致Carbon实例在app.timezone时区中保存到数据库,而数据库中的所有日期都应该是UTC,因此我失去了一致性.

我目前app.timezone在App配置中设置为UTC,但我还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,可能是在将Carbon变成字符串并在那里进行之前捕获执行？

编辑:

我试过的事情:

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

对于我的应用程序遇到同样的问题,其中远程网站将以UTC格式存储日期,并且我必须根据登录用户显示实际日期,我想出了覆盖Laravel Eloquent模型.

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

<?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;
    }
}

也许这对其他绊倒这个问题的人有用.

作为参考

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

Answer 2

如果我理解正确，您想要实现的是将时区从 A 格式转换为 B 格式并将其发送给用户，其中 A 格式存储在数据库中，从数据库检索记录后转换为 B 格式。

这是一个巧妙的方法来做到这一点。

User在、 等模型中MyModel需要转换的地方，在 model 中添加一个函数：

public function getConversionAttribute()
{
    $conversion = Convert($this->SomeDate);
    //Convert is the customized function to convert data format
    //SomeDate is the original column name of dates stored in your database
    return $conversion;
}

现在，如果您使用 查询 User 模型或 MyModel $user = User::find(1)，您现在可以通过使用 访问转换属性来获取转换后的日期$user->conversion。

干杯!

但是，以这种方式添加的属性不会包含在转换后的数组中。您需要在模型中添加另一个函数。

public function toArray()
{
    $array = parent::toArray();
    //if you want to override the original attribute
    $array['SomeDate'] = $this->conversion;
    //if you want to keep both the original format and the current format
    //use this: $array['Conversion'] = $this->conversion;
    return $array;
}

通用版本：

public function toArray() {
    $array = parent::toArray();
    //if you want to override the original attribute
    $dates = $this->getDates();

    foreach ($dates as $date) {
        $local = $this->{$date}->copy();
        $local->timezone = ...
        $array[$date] = (string)$local;
    }
    //if you want to keep both the original format and the current format
    //use this: $array['Conversion'] = $this->conversion;
    return $array;
}