--- /dev/null
+<?php
+
+namespace Drupal\Core\Field\Plugin\Field\FieldType;
+
+use Drupal\Component\Utility\Random;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+
+/**
+ * Defines the 'string_long' field type.
+ *
+ * @FieldType(
+ * id = "string_long",
+ * label = @Translation("Text (plain, long)"),
+ * description = @Translation("A field containing a long string value."),
+ * category = @Translation("Text"),
+ * default_widget = "string_textarea",
+ * default_formatter = "basic_string",
+ * )
+ */
+class StringLongItem extends StringItemBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function schema(FieldStorageDefinitionInterface $field_definition) {
+ return [
+ 'columns' => [
+ 'value' => [
+ 'type' => $field_definition->getSetting('case_sensitive') ? 'blob' : 'text',
+ 'size' => 'big',
+ ],
+ ],
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
+ $random = new Random();
+ $values['value'] = $random->paragraphs();
+ return $values;
+ }
+
+}