<?php

namespace Drupal\example_block\Plugin\Block;


use Drupal\Core\Block\BlockBase;
use Drupal\Core\Block\BlockPluginInterface;
use Drupal\Core\Form\FormStateInterface;


/**
 * Provides a Eventbrite attendees list Block.
 *
 * @Block(
 *   id = "example_block_id",
 *   admin_label = @Translation("My example block")
 * )
 */
class ExampleBlock extends BlockBase implements BlockPluginInterface
{
	/**
	 * Return the block contents
	 *
	 * {@inheritdoc}
	 */
	public function build()
	{
		$config = $this->getConfiguration();

		return "Hello {$config['some_text']}";
	}

	/**
	 * Return a Form API array
	 *
	 * {@inheritdoc}
	 */
	public function blockForm($form, FormStateInterface $form_state)
	{
		$form = parent::blockForm($form, $form_state);

		$config = $this->getConfiguration();

		$form['some_text'] = [
			'#type' => 'textfield',
			'#title' => $this->t('Some Text'),
			'#default_value' => isset($config['some_text']) ? $config['some_text'] : 'Jonathan',
		];

		return $form;
	}

	/**
	 * Update the configuration values from the form state
	 *
	 * {@inheritdoc}
	 */
	public function blockSubmit($form, FormStateInterface $form_state)
	{
		$this->configuration['some_text'] = $form_state->getValue('some_text');
	}
}