Datetime.php

<?php

namespace Drupal\Core\Datetime\Element;

use Drupal\Component\Utility\NestedArray;
use Drupal\Core\Datetime\DrupalDateTime;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Datetime\Entity\DateFormat;

/**
 * Provides a datetime element.
 *
 * @FormElement("datetime")
 */
class Datetime extends DateElementBase {
    
    /**
     * @var \DateTimeInterface
     */
    protected static $dateExample;
    
    /**
     * {@inheritdoc}
     */
    public function getInfo() {
        $date_format = '';
        $time_format = '';
        // Date formats cannot be loaded during install or update.
        if (!defined('MAINTENANCE_MODE')) {
            if ($date_format_entity = DateFormat::load('html_date')) {
                
                /** @var $date_format_entity \Drupal\Core\Datetime\DateFormatInterface */
                $date_format = $date_format_entity->getPattern();
            }
            if ($time_format_entity = DateFormat::load('html_time')) {
                
                /** @var $time_format_entity \Drupal\Core\Datetime\DateFormatInterface */
                $time_format = $time_format_entity->getPattern();
            }
        }
        $class = get_class($this);
        // Note that since this information is cached, the #date_timezone property
        // is not set here, as this needs to vary potentially by-user.
        return [
            '#input' => TRUE,
            '#element_validate' => [
                [
                    $class,
                    'validateDatetime',
                ],
            ],
            '#process' => [
                [
                    $class,
                    'processDatetime',
                ],
                [
                    $class,
                    'processAjaxForm',
                ],
                [
                    $class,
                    'processGroup',
                ],
            ],
            '#pre_render' => [
                [
                    $class,
                    'preRenderGroup',
                ],
            ],
            '#theme' => 'datetime_form',
            '#theme_wrappers' => [
                'datetime_wrapper',
            ],
            '#date_date_format' => $date_format,
            '#date_date_element' => 'date',
            '#date_date_callbacks' => [],
            '#date_time_format' => $time_format,
            '#date_time_element' => 'time',
            '#date_time_callbacks' => [],
            '#date_year_range' => '1900:2050',
            '#date_increment' => 1,
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public static function valueCallback(&$element, $input, FormStateInterface $form_state) {
        $element += [
            '#date_timezone' => date_default_timezone_get(),
        ];
        if ($input !== FALSE) {
            $date_input = $element['#date_date_element'] != 'none' && !empty($input['date']) ? $input['date'] : '';
            $time_input = $element['#date_time_element'] != 'none' && !empty($input['time']) ? $input['time'] : '';
            $date_format = $element['#date_date_element'] != 'none' ? static::getHtml5DateFormat($element) : '';
            $time_format = $element['#date_time_element'] != 'none' ? static::getHtml5TimeFormat($element) : '';
            // Seconds will be omitted in a post in case there's no entry.
            if (!empty($time_input) && strlen($time_input) == 5) {
                $time_input .= ':00';
            }
            try {
                $date_time_format = trim($date_format . ' ' . $time_format);
                $date_time_input = trim($date_input . ' ' . $time_input);
                $date = DrupalDateTime::createFromFormat($date_time_format, $date_time_input, $element['#date_timezone']);
            } catch (\Exception $e) {
                $date = NULL;
            }
            $input = [
                'date' => $date_input,
                'time' => $time_input,
                'object' => $date,
            ];
        }
        else {
            $date = isset($element['#default_value']) ? $element['#default_value'] : NULL;
            if ($date instanceof DrupalDateTime && !$date->hasErrors()) {
                $date->setTimezone(new \DateTimeZone($element['#date_timezone']));
                $input = [
                    'date' => $date->format($element['#date_date_format']),
                    'time' => $date->format($element['#date_time_format']),
                    'object' => $date,
                ];
            }
            else {
                $input = [
                    'date' => '',
                    'time' => '',
                    'object' => NULL,
                ];
            }
        }
        return $input;
    }
    
    /**
     * Expands a datetime element type into date and/or time elements.
     *
     * All form elements are designed to have sane defaults so any or all can be
     * omitted. Both the date and time components are configurable so they can be
     * output as HTML5 datetime elements or not, as desired.
     *
     * Examples of possible configurations include:
     *   HTML5 date and time:
     *     #date_date_element = 'date';
     *     #date_time_element = 'time';
     *   HTML5 datetime:
     *     #date_date_element = 'datetime';
     *     #date_time_element = 'none';
     *   HTML5 time only:
     *     #date_date_element = 'none';
     *     #date_time_element = 'time'
     *   Non-HTML5:
     *     #date_date_element = 'text';
     *     #date_time_element = 'text';
     *
     * Required settings:
     *   - #default_value: A DrupalDateTime object, adjusted to the proper local
     *     timezone. Converting a date stored in the database from UTC to the local
     *     zone and converting it back to UTC before storing it is not handled here.
     *     This element accepts a date as the default value, and then converts the
     *     user input strings back into a new date object on submission. No timezone
     *     adjustment is performed.
     * Optional properties include:
     *   - #date_date_format: A date format string that describes the format that
     *     should be displayed to the end user for the date. When using HTML5
     *     elements the format MUST use the appropriate HTML5 format for that
     *     element, no other format will work. See the
     *     DateFormatterInterface::format() function for a list of the possible
     *     formats and HTML5 standards for the HTML5 requirements. Defaults to the
     *     right HTML5 format for the chosen element if a HTML5 element is used,
     *     otherwise defaults to DateFormat::load('html_date')->getPattern().
     *   - #date_date_element: The date element. Options are:
     *     - datetime: Use the HTML5 datetime element type.
     *     - datetime-local: Use the HTML5 datetime-local element type.
     *     - date: Use the HTML5 date element type.
     *     - text: No HTML5 element, use a normal text field.
     *     - none: Do not display a date element.
     *   - #date_date_callbacks: Array of optional callbacks for the date element.
     *     Can be used to add a jQuery datepicker.
     *   - #date_time_element: The time element. Options are:
     *     - time: Use a HTML5 time element type.
     *     - text: No HTML5 element, use a normal text field.
     *     - none: Do not display a time element.
     *   - #date_time_format: A date format string that describes the format that
     *     should be displayed to the end user for the time. When using HTML5
     *     elements the format MUST use the appropriate HTML5 format for that
     *     element, no other format will work. See the
     *     DateFormatterInterface::format() function for a list of the possible
     *     formats and HTML5 standards for the HTML5 requirements. Defaults to the
     *     right HTML5 format for the chosen element if a HTML5 element is used,
     *     otherwise defaults to DateFormat::load('html_time')->getPattern().
     *   - #date_time_callbacks: An array of optional callbacks for the time
     *     element. Can be used to add a jQuery timepicker or an 'All day' checkbox.
     *   - #date_year_range: A description of the range of years to allow, like
     *     '1900:2050', '-3:+3' or '2000:+3', where the first value describes the
     *     earliest year and the second the latest year in the range. A year
     *     in either position means that specific year. A +/- value describes a
     *     dynamic value that is that many years earlier or later than the current
     *     year at the time the form is displayed. Used in jQueryUI datepicker year
     *     range and HTML5 min/max date settings. Defaults to '1900:2050'.
     *   - #date_increment: The interval (step) to use when incrementing or
     *     decrementing time, in seconds. For example, if this value is set to 30,
     *     time increases (or decreases) in steps of 30 seconds (00:00:00,
     *     00:00:30, 00:01:00, and so on.) If this value is a multiple of 60, the
     *     "seconds"-component will not be shown in the input. Used for HTML5 step
     *     values and jQueryUI datepicker settings. Defaults to 1 to show every
     *     second.
     *   - #date_timezone: The Time Zone Identifier (TZID) to use when displaying
     *     or interpreting dates, i.e: 'Asia/Kolkata'. Defaults to the value
     *     returned by date_default_timezone_get().
     *
     * Example usage:
     * @code
     *   $form = array(
     *     '#type' => 'datetime',
     *     '#default_value' => new DrupalDateTime('2000-01-01 00:00:00'),
     *     '#date_date_element' => 'date',
     *     '#date_time_element' => 'none',
     *     '#date_year_range' => '2010:+3',
     *     '#date_timezone' => 'Asia/Kolkata',
     *   );
     * @endcode
     *
     * @param array $element
     *   The form element whose value is being processed.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current state of the form.
     * @param array $complete_form
     *   The complete form structure.
     *
     * @return array
     *   The form element whose value has been processed.
     *
     * @see \Drupal\Core\Datetime\DateFormatterInterface::format()
     */
    public static function processDatetime(&$element, FormStateInterface $form_state, &$complete_form) {
        $format_settings = [];
        // The value callback has populated the #value array.
        $date = !empty($element['#value']['object']) ? $element['#value']['object'] : NULL;
        $element['#tree'] = TRUE;
        if ($element['#date_date_element'] != 'none') {
            $date_format = $element['#date_date_element'] != 'none' ? static::getHtml5DateFormat($element) : '';
            $date_value = !empty($date) ? $date->format($date_format, $format_settings) : $element['#value']['date'];
            // Creating format examples on every individual date item is messy, and
            // placeholders are invalid for HTML5 date and datetime, so an example
            // format is appended to the title to appear in tooltips.
            $extra_attributes = [
                'title' => t('Date (e.g. @format)', [
                    '@format' => static::formatExample($date_format),
                ]),
                'type' => $element['#date_date_element'],
            ];
            // Adds the HTML5 date attributes.
            if ($date instanceof DrupalDateTime && !$date->hasErrors()) {
                $html5_min = clone $date;
                $range = static::datetimeRangeYears($element['#date_year_range'], $date);
                $html5_min->setDate($range[0], 1, 1)
                    ->setTime(0, 0, 0);
                $html5_max = clone $date;
                $html5_max->setDate($range[1], 12, 31)
                    ->setTime(23, 59, 59);
                $extra_attributes += [
                    'min' => $html5_min->format($date_format, $format_settings),
                    'max' => $html5_max->format($date_format, $format_settings),
                ];
            }
            $element['date'] = [
                '#type' => 'date',
                '#title' => t('Date'),
                '#title_display' => 'invisible',
                '#value' => $date_value,
                '#attributes' => $element['#attributes'] + $extra_attributes,
                '#required' => $element['#required'],
                '#size' => max(12, strlen($element['#value']['date'])),
                '#error_no_message' => TRUE,
                '#date_date_format' => $element['#date_date_format'],
            ];
            // Allows custom callbacks to alter the element.
            if (!empty($element['#date_date_callbacks'])) {
                foreach ($element['#date_date_callbacks'] as $callback) {
                    if (is_callable($callback)) {
                        $callback($element, $form_state, $date);
                    }
                }
            }
        }
        if ($element['#date_time_element'] != 'none') {
            $time_format = $element['#date_time_element'] != 'none' ? static::getHtml5TimeFormat($element) : '';
            $time_value = !empty($date) ? $date->format($time_format, $format_settings) : $element['#value']['time'];
            // Adds the HTML5 attributes.
            $extra_attributes = [
                'title' => t('Time (e.g. @format)', [
                    '@format' => static::formatExample($time_format),
                ]),
                'type' => $element['#date_time_element'],
                'step' => $element['#date_increment'],
            ];
            $element['time'] = [
                '#type' => 'date',
                '#title' => t('Time'),
                '#title_display' => 'invisible',
                '#value' => $time_value,
                '#attributes' => $element['#attributes'] + $extra_attributes,
                '#required' => $element['#required'],
                '#size' => 12,
                '#error_no_message' => TRUE,
            ];
            // Allows custom callbacks to alter the element.
            if (!empty($element['#date_time_callbacks'])) {
                foreach ($element['#date_time_callbacks'] as $callback) {
                    if (function_exists($callback)) {
                        $callback($element, $form_state, $date);
                    }
                }
            }
        }
        return $element;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function processAjaxForm(&$element, FormStateInterface $form_state, &$complete_form) {
        $element = parent::processAjaxForm($element, $form_state, $complete_form);
        // Copy the #ajax settings to the child elements.
        if (isset($element['#ajax'])) {
            if (isset($element['date'])) {
                $element['date']['#ajax'] = $element['#ajax'];
            }
            if (isset($element['time'])) {
                $element['time']['#ajax'] = $element['#ajax'];
            }
        }
        return $element;
    }
    
    /**
     * Validation callback for a datetime element.
     *
     * If the date is valid, the date object created from the user input is set in
     * the form for use by the caller. The work of compiling the user input back
     * into a date object is handled by the value callback, so we can use it here.
     * We also have the raw input available for validation testing.
     *
     * @param array $element
     *   The form element whose value is being validated.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current state of the form.
     * @param array $complete_form
     *   The complete form structure.
     */
    public static function validateDatetime(&$element, FormStateInterface $form_state, &$complete_form) {
        $input_exists = FALSE;
        $input = NestedArray::getValue($form_state->getValues(), $element['#parents'], $input_exists);
        if ($input_exists) {
            $title = !empty($element['#title']) ? $element['#title'] : '';
            $date_format = $element['#date_date_element'] != 'none' ? static::getHtml5DateFormat($element) : '';
            $time_format = $element['#date_time_element'] != 'none' ? static::getHtml5TimeFormat($element) : '';
            $format = trim($date_format . ' ' . $time_format);
            // If there's empty input and the field is not required, set it to empty.
            if (empty($input['date']) && empty($input['time']) && !$element['#required']) {
                $form_state->setValueForElement($element, NULL);
            }
            elseif (empty($input['date']) && empty($input['time']) && $element['#required']) {
                $form_state->setError($element, t('The %field date is required. Please enter a date in the format %format.', [
                    '%field' => $title,
                    '%format' => static::formatExample($format),
                ]));
            }
            else {
                // If the date is valid, set it.
                $date = $input['object'];
                if ($date instanceof DrupalDateTime && !$date->hasErrors()) {
                    $form_state->setValueForElement($element, $date);
                }
                else {
                    $form_state->setError($element, t('The %field date is invalid. Please enter a date in the format %format.', [
                        '%field' => $title,
                        '%format' => static::formatExample($format),
                    ]));
                }
            }
        }
    }
    
    /**
     * Creates an example for a date format.
     *
     * This is centralized for a consistent method of creating these examples.
     *
     * @param string $format
     *
     * @return string
     */
    public static function formatExample($format) {
        if (!static::$dateExample) {
            static::$dateExample = new DrupalDateTime();
        }
        return static::$dateExample->format($format);
    }
    
    /**
     * Retrieves the right format for a HTML5 date element.
     *
     * The format is important because these elements will not work with any other
     * format.
     *
     * @param array $element
     *   The $element to assess.
     *
     * @return string
     *   Returns the right format for the date element, or the original format
     *   if this is not a HTML5 element.
     */
    protected static function getHtml5DateFormat($element) {
        switch ($element['#date_date_element']) {
            case 'date':
                return DateFormat::load('html_date')->getPattern();
            case 'datetime':
            case 'datetime-local':
                return DateFormat::load('html_datetime')->getPattern();
            default:
                return $element['#date_date_format'];
        }
    }
    
    /**
     * Retrieves the right format for a HTML5 time element.
     *
     * The format is important because these elements will not work with any other
     * format.
     *
     * @param array $element
     *   The $element to assess.
     *
     * @return string
     *   Returns the right format for the time element, or the original format
     *   if this is not a HTML5 element.
     */
    protected static function getHtml5TimeFormat($element) {
        switch ($element['#date_time_element']) {
            case 'time':
                return DateFormat::load('html_time')->getPattern();
            default:
                return $element['#date_time_format'];
        }
    }

}