FieldTest.php

<?php

namespace Drupal\views_test_data\Plugin\views\field;

use Drupal\views\Plugin\views\field\FieldPluginBase;
use Drupal\views\ResultRow;

/**
 * @ViewsField("test_field")
 */
class FieldTest extends FieldPluginBase {
    
    /**
     * A temporary stored test value for the test.
     *
     * @var string
     */
    protected $testValue;
    
    /**
     * Sets the testValue property.
     *
     * @param string $value
     *   The test value to set.
     */
    public function setTestValue($value) {
        $this->testValue = $value;
    }
    
    /**
     * Returns the testValue property.
     *
     * @return string
     */
    public function getTestValue() {
        return $this->testValue;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function addSelfTokens(&$tokens, $item) {
        $tokens['{{ test_token }}'] = $this->getTestValue();
    }
    
    /**
     * {@inheritdoc}
     */
    public function render(ResultRow $values) {
        return $this->sanitizeValue($this->getTestValue());
    }
    
    /**
     * A mock function which allows to call placeholder from public.
     *
     * @return string
     *   The result of the placeholder method.
     */
    public function getPlaceholder() {
        return $this->placeholder();
    }

}