mytinytodo/src/includes/api/ExtSettingsController.php

<?php declare(strict_types=1);

class ExtSettingsController extends ApiController {

    /**
     * Get extension settings page
     * @return void
     * @throws Exception
     */
    function get($ext)
    {
        /** @var MTTExtension|MTTExtensionSettingsInterface $instance */
        $instance = $this->extInstance($ext);
        if (!$instance) {
            return;
        }

        $data = $instance->settingsPage();

        $title = htmlspecialchars($instance::title);
        $escapedExt = htmlspecialchars($ext);
        $e = function($s) { return __($s, true); };
        $data =
<<<EOD
<h3 class="page-title"><a class="mtt-back-button"></a> $title </h3>
<div id="settings_msg" style="display:none"></div>
<form id="ext_settings_form" data-ext="$escapedExt">
  <div class="mtt-settings-table">
    $data
    <div class="form-bottom-buttons">
      <button type="submit">{$e('set_submit')}</button>
      <button type="button" class="mtt-back-button">{$e('set_cancel')}</button>
    </div>
  </div>
</form>
EOD;

        $this->response->htmlContent($data);
    }

    /**
     * Save extension settings
     * @return void
     * @throws Exception
     */
    function put($ext)
    {
        /** @var MTTExtension|MTTExtensionSettingsInterface $instance */
        $instance = $this->extInstance($ext);
        if (!$instance) {
            return;
        }
        //$userError = '';
        $saved = $instance->saveSettings($this->req->jsonBody ?? [], $userError);
        $a = [ 'saved' => (int)$saved ];
        if ($userError) {
            $a['msg'] = $userError;
        }
        $this->response->data = $a;
    }

    private function extInstance($ext): ?MTTExtensionSettingsInterface
    {
        $instance = MTTExtensionLoader::extensionInstance($ext);
        if (!$instance) {
            $this->response->data = [ 'msg' => "Unknown extension" ];
            $this->response->code = 404;
            return null;
        }
        if (! ($instance instanceof MTTExtensionSettingsInterface) ) {
            $this->response->data = [ 'msg' => "No settings page for extension" ];
            $this->response->code = 500;
            return null;
        }
        return $instance;
    }

}