de.systopia.twingle/CRM/Twingle/Form/Settings.php

<?php
/*------------------------------------------------------------+
| SYSTOPIA Twingle Integration                                |
| Copyright (C) 2018 SYSTOPIA                                 |
| Author: J. Schuppe (schuppe@systopia.de)                    |
+-------------------------------------------------------------+
| This program is released as free software under the         |
| Affero GPL license. You can redistribute it and/or          |
| modify it under the terms of this license which you         |
| can read by viewing the included agpl.txt or online         |
| at www.gnu.org/licenses/agpl.html. Removal of this          |
| copyright header is strictly prohibited without             |
| written permission from the original author(s).             |
+-------------------------------------------------------------*/

use CRM_Twingle_ExtensionUtil as E;

/**
 * Form controller class
 *
 * @see https://wiki.civicrm.org/confluence/display/CRMDOC/QuickForm+Reference
 */
class CRM_Twingle_Form_Settings extends CRM_Core_Form {

  private $_settingFilter = array('group' => 'de.systopia.twingle');

  //everything from this line down is generic & can be re-used for a setting form in another extension
  //actually - I lied - I added a specific call in getFormSettings
  private $_submittedValues = array();
  private $_settings = array();

  /**
   * @inheritdoc
   */
  function buildQuickForm() {
    // Set redirect destination.
    $this->controller->_destination = CRM_Utils_System::url('civicrm/admin/settings/twingle', 'reset=1');

    $settings = $this->getFormSettings();
    $form_elements = array();

    foreach ($settings as $name => $setting) {
      if (isset($setting['quick_form_type'])) {
        $add = 'add' . $setting['quick_form_type'];
        if ($add == 'addElement') {
          $this->$add(
            $setting['html_type'],
            $name,
            ts($setting['title']),
            CRM_Utils_Array::value('html_attributes', $setting, array())
          );
        }
        elseif ($setting['html_type'] == 'Select') {
          $optionValues = array();
          if (!empty($setting['pseudoconstant']) && !empty($setting['pseudoconstant']['optionGroupName'])) {
            $optionValues = CRM_Core_OptionGroup::values($setting['pseudoconstant']['optionGroupName'], FALSE, FALSE, FALSE, NULL, 'name');
          }
          $this->add(
            'select',
            $setting['name'],
            $setting['title'],
            $optionValues,
            FALSE,
            CRM_Utils_Array::value('html_attributes', $setting, array())
          );
        }
        else {
          $this->$add($name, ts($setting['title']));
        }
        $form_elements[$setting['name']] = array('description' => ts($setting['description']));

        // Disable CiviSEPA setting if the extension is not installed.
        if ($name == 'twingle_use_sepa') {
          $sepa_extension = civicrm_api3('Extension', 'get', array(
            'full_name' => 'org.project60.sepa',
            'is_active' => 1,
          ));
          if ($sepa_extension['count'] == 0) {
            $element = $this->getElement('twingle_use_sepa');
            $element->freeze();
            $form_elements['twingle_use_sepa']['description'] .= ' <span class="error">The <a href="https://github.com/project60/org.project60.sepa" target="_blank" title="Extension page">CiviSEPA (<kbd>org.project60.sepa</kbd>) extension</a> is not installed.</span>';
          }
        }
      }
    }

    $this->assign('formElements', $form_elements);

    $this->addButtons(array(
      array (
        'type' => 'submit',
        'name' => ts('Save'),
        'isDefault' => TRUE,
      )
    ));

    // Export form elements.
    $this->assign('elementNames', $this->getRenderableElementNames());
    parent::buildQuickForm();
  }

  /**
   * @inheritdoc
   */
  function postProcess() {
    $this->_submittedValues = $this->exportValues();
    $this->saveSettings();
    parent::postProcess();
  }

  /**
   * Get the fields/elements defined in this form.
   *
   * @return array (string)
   */
  function getRenderableElementNames() {
    // The _elements list includes some items which should not be
    // auto-rendered in the loop -- such as "qfKey" and "buttons". These
    // items don't have labels. We'll identify renderable by filtering on
    // the 'label'.
    $elementNames = array();
    foreach ($this->_elements as $element) {
      /* @var \HTML_QuickForm_element $element */
      $label = $element->getLabel();
      if (!empty($label)) {
        $elementNames[] = $element->getName();
      }
    }
    return $elementNames;
  }
  /**
   * Get the settings we are going to allow to be set on this form.
   *
   * @return array
   */
  function getFormSettings() {
    if (empty($this->_settings)) {
      $settings = civicrm_api3('setting', 'getfields', array('filters' => $this->_settingFilter));
      $settings = $settings['values'];
    }
    else {
      $settings = $this->_settings;
    }
    return $settings;
  }
  /**
   * Save the settings set on this form.
   */
  function saveSettings() {
    $settings = $this->getFormSettings();
    $values = array_intersect_key($this->_submittedValues, $settings);
    civicrm_api3('setting', 'create', $values);
  }
  /**
   * @inheritdoc
   */
  function setDefaultValues() {
    $existing = civicrm_api3('setting', 'get', array('return' => array_keys($this->getFormSettings())));
    $defaults = array();
    $domainID = CRM_Core_Config::domainID();
    foreach ($existing['values'][$domainID] as $name => $value) {
      $defaults[$name] = $value;
    }
    return $defaults;
  }

  /**
   * @inheritdoc
   */
  public function addRules() {
    $this->addFormRule(array('CRM_Twingle_Form_Settings', 'validateSettingsForm'));
  }

  /**
   * Validates the profile form.
   *
   * @param array $values
   *   The submitted form values, keyed by form element name.
   *
   * @return bool | array
   *   TRUE when the form was successfully validated, or an array of error
   *   messages, keyed by form element name.
   */
  public static function validateSettingsForm($values) {
    $errors = array();

    return empty($errors) ? TRUE : $errors;
  }

}