autofill_fields.module

<?php

use Drupal\Core\Entity\Entity\EntityFormDisplay;
use Drupal\Core\Datetime\DrupalDateTime;
use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Field\WidgetInterface;
use Drupal\Core\Form\FormStateInterface;

/**
 * Implements hook_field_widget_third_party_settings_form().
 */
function autofill_fields_field_widget_third_party_settings_form(WidgetInterface $plugin, FieldDefinitionInterface $field_definition, $form_mode, $form, FormStateInterface $form_state) {
    // Skip some fields.
    if (in_array($field_definition->getName(), [
        'authored_by',
        'authored_on',
        'title',
        'path',
        'comment',
    ])) {
        return [];
    }
    $element = [
        'autofill' => [
            '#type' => 'checkbox',
            '#title' => t('Autofill field'),
            '#description' => t('Autofill field for new entities with last used value.'),
            '#default_value' => $plugin->getThirdPartySetting('autofill_fields', 'autofill', FALSE),
        ],
    ];
    return $element;
}

/**
 * Implements hook_field_widget_settings_summary_alter().
*/
function autofill_fields_field_widget_settings_summary_alter(&$summary, $context) {
    if ($context['widget']->getThirdPartySetting('autofill_fields', 'autofill')) {
        $summary[] = t('Autofill enabled.');
    }
}

/**
 * Implements hook_field_widget_form_alter().
 */
function autofill_fields_field_widget_form_alter(&$element, FormStateInterface $form_state, $context) {
    // Only run for logged in users.
    if (!($user_id = \Drupal::currentUser()->id())) {
        return;
    }
    $entity = $form_state->getFormObject()
        ->getEntity();
    // Only run for new entities; we don't want to overwrite desired data.
    if (!$entity->isNew()) {
        return;
    }
    $plugin = $context['widget'];
    // Check that it is enabled for this field.
    if (!$plugin->getThirdPartySetting('autofill_fields', 'autofill')) {
        return;
    }
    $field_definition = $context['items']->getFieldDefinition();
    $type = $field_definition->getType();
    $plugin_id = $plugin->getPluginId();
    $values = $plugin->getThirdPartySetting('autofill_fields', 'stored', []);
    if (isset($values[$user_id])) {
        $entity_type_manager = \Drupal::service('entity_type.manager');
        if ($type == 'text_with_summary') {
            $element['#default_value'] = $values[$user_id][0]['value'];
            $element['#format'] = $values[$user_id][0]['format'];
            $element['summary']['#default_value'] = $values[$user_id][0]['summary'];
        }
        elseif ($type == 'entity_reference') {
            $value = isset($values[$user_id]['target_id']) ? $values[$user_id]['target_id'] : $values[$user_id];
            if ($plugin_id == 'options_select' || $plugin_id == 'options_buttons') {
                $element['#default_value'] = [];
                foreach ($value as $reference) {
                    $element['#default_value'][] = $reference['target_id'];
                }
            }
            elseif ($plugin_id == 'entity_reference_autocomplete') {
                if (!$value[$element['target_id']['#delta']]['target_id']) {
                    return;
                }
                $element['target_id']['#default_value'] = $entity_type_manager->getStorage($element['target_id']['#target_type'])
                    ->load($value[$element['target_id']['#delta']]['target_id']);
            }
            elseif ($plugin_id == 'entity_reference_autocomplete_tags') {
                $element['target_id']['#default_value'] = [];
                foreach ($value as $reference) {
                    $element['target_id']['#default_value'][] = $entity_type_manager->getStorage($element['target_id']['#target_type'])
                        ->load($reference['target_id']);
                }
            }
        }
        elseif ($type == 'decimal') {
            if ($plugin_id == 'number') {
                $element['value']['#default_value'] = $values[$user_id][$element['value']['#delta']]['value'];
            }
        }
        elseif ($type == 'datetime') {
            if ($plugin_id == 'datetime_default') {
                $element['value']['#default_value'] = new DrupalDateTime($values[$user_id]);
            }
        }
        else {
            var_dump($type);
            var_dump($values[$user_id]);
            var_dump($element);
        }
    }
}

/**
 * Implements hook_form_alter().
 */
function autofill_fields_form_alter(&$form, FormStateInterface $form_state, $form_id) {
    $info = $form_state->getBuildInfo();
    if (isset($info['base_form_id']) && in_array($info['base_form_id'], [
        'node_form',
        'media_form',
    ])) {
        if (isset($form['actions']['publish'])) {
            $form['actions']['publish']['#submit'][] = 'autofill_fields_submit';
        }
        else {
            $form['actions']['submit']['#submit'][] = 'autofill_fields_submit';
        }
    }
}

/**
 * Submit function to save field values per entity create/edit action.
 */
function autofill_fields_submit($form, FormStateInterface $form_state) {
    if (!($user_id = \Drupal::currentUser()->id())) {
        return;
    }
    // Ensure that the form entity is properly loaded.
    if (!($entity = $form_state->getFormObject()
        ->getEntity())) {
        return;
    }
    
    //TODO: get real form mode.
    $form_mode = 'default';
    $entity_form_display = EntityFormDisplay::load($entity->getEntityTypeId() . '.' . $entity->getType() . '.' . $form_mode);
    foreach ($entity_form_display->getComponents() as $name => $component) {
        if (empty($component['third_party_settings']['autofill_fields']['autofill'])) {
            continue;
        }
        if (!isset($component['third_party_settings']['autofill_fields']['stored'])) {
            $component['third_party_settings']['autofill_fields']['stored'] = [];
        }
        $component['third_party_settings']['autofill_fields']['stored'][$user_id] = $form_state->getValue($name);
        if ($component['type'] == 'datetime_default') {
            $value = $form_state->getValue($name)[0]['value']
                ->format('c');
        }
        else {
            $value = $form_state->getValue($name);
        }
        $component['third_party_settings']['autofill_fields']['stored'][$user_id] = $value;
        $entity_form_display->setComponent($name, $component);
    }
    $entity_form_display->save();
}