Cómo utilizar JDate

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Introducción

JDate es una clase auxiliar, se extiende de la clase DateTime de PHP, permite a los desarrolladores manejar el formato de fechas de forma más eficiente. La clase permite a los desarrolladores dar formato legibles a cadenas fechas, interacción MySQL, cálculo timestamp de UNIX y también proporciona métodos auxiliares para trabajar con diferentes zonas horarias.

Regarding the "JDate" class name: This page has been updated to utilise namespaced class names. `JDate`, `JApplication` and other similarly named classes you will see throughout the Joomla documentation are actually class aliases, maintained for legacy reasons. It is recommended to use namespaced access to Joomla classes, which will improve your development experience by providing better code hints and checks in your editor, leading to fewer errors.

You can view the full list of aliased classes in this file inside the Joomla codebase.

Crear una instancia de JDate

Todos los métodos auxiliares de fecha requieren una instancia de la clase JDate. Para empezar, debes crear una. Un objeto JDate puede ser creado de dos maneras. Uno es el típico método nativo de simplemente crear una nueva instancia:

use Joomla\CMS\Date\Date;

$date = new Date(); // Creates a new Date object equal to the current time.

También puedes crear una instancia mediante el método estático definido en JDate:

use Joomla\CMS\Date\Date;

$date = Date::getInstance(); // Alias of 'new Date();'

No hay ninguna diferencia entre estos métodos, ya que JDate::getInstance simplemente crea una nueva instancia de JDate exactamente igual que el primer método que se muestra.

Alternativamente, también puedes recuperar la fecha actual (como un objeto JDate) de JApplication, mediante:

use Joomla\CMS\Factory;

$date = Factory::getDate();

Argumentos

El constructor JDate (y el método estático getInstance) acepta dos parámetros opcionales: Una cadena de fecha a formato y una zona horaria. No pasar una cadena de fecha creará un objeto JDate con la fecha y la hora actual, mientras que no pasar una zona horaria permitirá al objeto JDate utilizar la zona horaria predeterminada.

El primer argumento, si se utiliza, debe ser una cadena que pueda ser analizada usando el constructor nativo de php, DateTime. E. g:

use Joomla\CMS\Date\Date;

$currentTime = new Date('now'); // Current date and time
$tomorrowTime = new Date('now +1 day'); // Current date and time, + 1 day.
$plus1MonthTime = new Date('now +1 month'); // Current date and time, + 1 month.
$plus1YearTime = new Date('now +1 year'); // Current date and time, + 1 year.
$plus1YearAnd1MonthTime = new Date('now +1 year +1 month'); // Current date and time, + 1 year and 1 month.
$plusTimeToTime = new Date('now +1 hour +30 minutes +3 seconds'); // Current date and time, + 1 hour, 30 minutes and 3 seconds
$plusTimeToTime = new Date('now -1 hour +30 minutes +3 seconds'); // Current date and time, + 1 hour, 30 minutes and 3 seconds
$combinedTimeToTime = new Date('now -1 hour -30 minutes 23 seconds'); // Current date and time, - 1 hour, +30 minutes and +23 seconds

$date = new Date('2012-12-1 15:20:00'); // 3:20 PM, December 1st, 2012

A Unix timestamp (in seconds) can also be passed as the first argument, in which case it will be internally uplifted into a date. If a timezone has been specified as the second argument to the constructor, it will be converted to that timezone.

Ejemplos

One note of caution when outputting Date objects in a user context: do not simply print them to the screen. The Date object's toString() method simply calls its parent's format() method, without consideration for timezones or localized date formatting. This will not result in a good user experience, and will lead to inconsistencies between the formatting in your extension, and elsewhere in Joomla. Instead, you should always output Dates using the methods shown below.

Common Date Formats

A number of date formats are predefined in Joomla as part of the base language packs. This is beneficial because it means date formats can be easily internationalised. A sample of the available format strings is below, from the en-GB language pack. It is highly recommended to utilise these formatting strings when outputting dates, so that your dates will be automatically re-formatted according to a user's locale. They can be retrieved in the same way as any language string (see below for examples).

DATE_FORMAT_LC="l, d F Y"
DATE_FORMAT_LC1="l, d F Y"
DATE_FORMAT_LC2="l, d F Y H:i"
DATE_FORMAT_LC3="d F Y"
DATE_FORMAT_LC4="Y-m-d"
DATE_FORMAT_LC5="Y-m-d H:i"
DATE_FORMAT_LC6="Y-m-d H:i:s"
DATE_FORMAT_JS1="y-m-d"
DATE_FORMAT_CALENDAR_DATE="%Y-%m-%d"
DATE_FORMAT_CALENDAR_DATETIME="%Y-%m-%d %H:%M:%S"
DATE_FORMAT_FILTER_DATE="Y-m-d"
DATE_FORMAT_FILTER_DATETIME="Y-m-d H:i:s"

The HtmlHelper Method (Recommended)

As with many common output items, the HtmlHelper class is here to...help! HtmlHelper's date() method will take any date-time string that the Date constructor would accept, along with a formatting string, and output the date appropriately for the current user's timezone settings. As such, this is the recommended method for outputting dates for the user.

use Joomla\CMS\HTML\HTMLHelper;
use Joomla\CMS\Language\Text;

$myDateString = '2012-12-1 15:20:00';
echo HtmlHelper::date($myDateString, Text::_('DATE_FORMAT_FILTER_DATETIME'));

The Date Object's format() Method

Another option is to format the Date manually. If this method is used, you will have to also manually retrieve and set the user's timezone. This method is more useful for formatting dates outside of the user interface, such as in system logs or API calls.

use Joomla\CMS\Language\Text;
use Joomla\CMS\Date\Date;
use Joomla\CMS\Factory;

$myDateString = '2012-12-1 15:20:00';
$timezone = Factory::getUser()->getTimezone();

$date = new Date($myDateString);
$date->setTimezone($timezone);
echo $date->format(Text::_('DATE_FORMAT_FILTER_DATETIME'));

Other Useful Code Examples

Quickly Outputting the Current Time

JFactory::getDate() obtiene un objeto JDate y después ejecutamos la función toFormat de JDate.

use Joomla\CMS\Factory;
use Joomla\CMS\HTML\HTMLHelper;
use Joomla\CMS\Language\Text;

// These two are functionally equivalent
echo HtmlHelper::date('now', Text::_('DATE_FORMAT_FILTER_DATETIME'));

$timezone = Factory::getUser()->getTimezone();
echo Factory::getDate()->setTimezone($timezone)->format(Text::_('DATE_FORMAT_FILTER_DATETIME'));

Adding and Subtracting from Dates

Because the Joomla Date object extends the PHP DateTime object, it provides methods for adding and subtracting from dates. The easiest of these methods to use is the modify() method, which accepts any relative modification string that the PHP strtotime() method would accept. For example:

use Joomla\CMS\Date\Date;

$date = new Date('2012-12-1 15:20:00');
$date->modify('+1 year');
echo $date->toSQL(); // 2013-12-01 15:20:00

There are also separate add() and sub() methods, for adding or subtracting time from a date object respectively. These accept PHP-standard DateInterval objects:

use Joomla\CMS\Date\Date;

$interval = new \DateInterval('P1Y1D'); // Interval represents 1 year and 1 day

$date1 = new Date('2012-12-1 15:20:00');
$date1->add($interval);
echo $date1->toSQL(); // 2013-12-02 15:20:00

$date2 = new Date('2012-12-1 15:20:00');
$date2->sub($interval);
echo $date2->toSQL(); // 2011-11-30 15:20:00

Outputting Dates in ISO 8601 Format

$date = new Date('2012-12-1 15:20:00');
$date->toISO8601(); // 20121201T152000Z

Outputting Dates in RFC 822 Format

$date = new Date('2012-12-1 15:20:00');
$date->toRFC822(); // Sat, 01 Dec 2012 15:20:00 +0000

Outputting Dates in SQL Date-Time Format

$date = new Date('20121201T152000Z');
$date->toSQL(); // 2012-12-01 15:20:00

Outputting Dates as Unix Timestamps

A Unix timestamp is expressed as the number of seconds that have passed since the Unix Epoch (the first second of Jan 1st 1970).

$date = new Date('20121201T152000Z');
$date->toUnix(); // 1354375200