USAGE.md

Usage

Make your objects depend on the Esi\Clock\ClockInterface interface. You can then use SystemClock to retrieve the current time or FrozenClock to retrieve a specific time.

For example:

<?php

declare(strict_types=1);

use Esi\Clock\ClockInterface;
use Esi\Clock\FrozenClock;
use Esi\Clock\SystemClock;

class MyCoolObject
{
    public function __construct(private ClockInterface $clock) {}

    public function getCurrentTime(): \DateTimeImmutable
    {
        return $this->clock->now();
    }

    public function freezeTime(): FrozenClock
    {
        if ($this->clock instanceof SystemClock) {
            return $this->clock->freeze();
        }

        return $this->clock->now();
    }
    // ...
}

<?php

declare(strict_types=1);

use Esi\Clock\SystemClock;
// ...
// ...

$clock = new MyCoolObject(new SystemClock('America/New_York'));
\var_dump($clock->getCurrentTime());
/*
class DateTimeImmutable#6 (3) {
  public $date =>
  string(26) "2024-04-10 13:46:30.724222"
  public $timezone_type =>
  int(3)
  public $timezone =>
  string(16) "America/New_York"
}
*/

$frozenClock = $clock->freezeTime();
$now = $frozenClock->now();

\var_dump($now);
/*
class DateTimeImmutable#7 (3) {
  public $date =>
  string(26) "2024-04-10 13:46:30.727716"
  public $timezone_type =>
  int(3)
  public $timezone =>
  string(16) "America/New_York"
}
*/

\sleep(5);

$stillNow = $frozenClock->now();
\var_dump($stillNow);
/*
class DateTimeImmutable#7 (3) {
  public $date =>
  string(26) "2024-04-10 13:46:30.727716"
  public $timezone_type =>
  int(3)
  public $timezone =>
  string(16) "America/New_York"
}
*/

SystemClock

Object that will return the current time based on the given timezone. The timezone passed to the constructor of SystemClock can either be a string of the timezone identifier, or a DateTimeZone object.

Create a new system clock:

<?php

declare(strict_types=1);

use Esi\Clock\SystemClock;

/**
 * You can either create your own \DateTimeZone object to pass to the SystemClock, or
 * you can pass the timezone string. E.g.:
 * 
 * @see https://www.php.net/datetimezone
 *
 * $clock = new SystemClock('America/New_York');
 */
$timezone = new \DateTimeZone('America/New_York');
$clock = new SystemClock($timezone);

$now = $clock->now();

/**
 * You can also make use of either `fromUtc()` or `fromSystemTimezone()`
 */
// Create a clock using UTC
$clock = SystemClock::fromUtc();
$now = $clock->now();

// Or the default system timezone
$clock = SystemClock::fromSystemTimezone();
$now = $clock->now();

FrozenClock

Test object that always returns a fixed time object. When creating a FrozenClock, it must be passed a \DateTimeImmutable object in its constructor. See DateTimeImmutable at php.net.

When creating the DateTimeImmutable object to pass into FrozenClock, if instantiated with no arguments it uses now to create the object with the current time. You can also pass a date/time string to set the FrozenClock to a specific time.

You can use DateTimeImmutable directly, or:

• DateTimeImmutable::createFromFormat
• DateTimeImmutable::createFromInterface - if using an object that implements DateTimeInterface, such as DateTime.

Create a new frozen clock:

<?php

declare(strict_types=1);

use Esi\Clock\FrozenClock;

$now = new \DateTimeImmutable();
$clock = new FrozenClock($now);

\sleep(5);

$stillNow = $clock->now();

You can also set the frozen clock to a new time by using it's setTo() method, which also requires a DateTimeImmutable object:

<?php

declare(strict_types=1);

use Esi\Clock\FrozenClock;

$clock = new FrozenClock(new \DateTimeImmutable());
$now = $clock->now();

$clock->setTo(new \DateTimeImmutable('+3 hours'));
$newNow = $clock->now();

You can also create a new frozen clock by freezing a system clock:

<?php

declare(strict_types=1);

use Esi\Clock\SystemClock;

$timezone = new \DateTimeZone('America/New_York');
$clock = new SystemClock($timezone);

$frozenClock = $clock->freeze();

$now = $clock->now();

\sleep(5);

$stillNow = $clock->now();