phorge-phorge/src/applications/search/field/PhabricatorSearchSelectField.php

<?php

final class PhabricatorSearchSelectField
  extends PhabricatorSearchField {

  private $options;

  public function setOptions(array $options) {
    $this->options = $options;
    return $this;
  }

  public function getOptions() {
    return $this->options;
  }

  protected function getDefaultValue() {
    return null;
  }

  protected function getValueFromRequest(AphrontRequest $request, $key) {
    return $request->getStr($key);
  }

  protected function newControl() {
    return id(new AphrontFormSelectControl())
      ->setOptions($this->getOptions());
  }

}