Answered Custom Manager Pages in 2.3

abstract class ExampleManagerController extends modExtraManagerController {
    /** @var Example $example */
    public $example = NULL;
 
    /* Initialize the main manager controller.*/
 
    public function initialize() {
        /* Instantiate the Example class in the controller */
        $path = $this->modx->getOption('example.core_path',
                NULL, $this->modx->getOption('core_path') .
                'components/example/') . 'model/example/';
        require_once $path . 'example.class.php';
        $this->example = new Example($this->modx);
 
        /* Optional alternative  - install PHP class as a service */
 
        /* $this->example = $this->modx->getService('example',
             'Example', $path);*/
 
        /* Add the main javascript class and our configuration */
        $this->addJavascript($this->example->config['jsUrl'] .
            'example.class.js');
        $this->addHtml('<script type="text/javascript">
        Ext.onReady(function() {
            Example.config = ' . $this->modx->toJSON($this->example->config) . ';
        });
        </script>');
    }
 
    public function getLanguageTopics() {
        return array('example:default');
    }
 
    public function checkPermissions() {
        return true;
    }
 
    public function getTemplateFile() {
        return $this->example->config['templatesPath'] . 'mgr.tpl';
    }
}
 
/**
 * The Index Manager Controller is the default one that gets
 * called when no action is present. */
 
class IndexManagerController extends ExampleManagerController {
 
    /* Defines the name or path to the default controller to load. */
    public static function getDefaultController() {
        return 'home';
    }
}

[28-Oct-2014 13:21:44 UTC] PHP Fatal error:  Class 'ExampleIndexManagerController' not found in /Volumes/Sites/cmp/core/model/modx/modmanagerresponse.class.php on line 185

$action = $modx->newObject('modAction');
$action->fromArray( array (
  'namespace' => 'example',
  'controller' => 'index',
  'haslayout' => 1,
  'lang_topics' => 'example:default',
  'assets' => '',
  'help_url' => '',
  'id' => 1,
), '', true, true);

$menus[1] = $modx->newObject('modMenu');
$menus[1]->fromArray( array (
  'text' => 'Example',
  'parent' => 'components',
  'description' => 'ex_menu_desc',
  'icon' => '',
  'menuindex' => 0,
  'params' => '',
  'handler' => '',
  'permissions' => '',
  'id' => 1,
), '', true, true);
$menus[1]->addOne($action);

class IndexManagerController extends ExampleManagerController {
 
    /* Defines the name or path to the default controller to load. */
    public static function getDefaultController() {
        return 'home';
    }
}

<?php
/**
 * The abstract Manager Controller.
 * In this class, we define stuff we want on all of our controllers.
 */

abstract class MyextraManagerController extends modExtraManagerController {
    /**
     * Initializes the main manager controller. You may want to load certain classes,
     * assets that are shared across all controllers or configuration. 
     *
     * All your other controllers in this namespace should extend this one.
     *
     * In this case we don't do anything useful, but as you build up more complex
     * extras, it helps to enforce this structure to make it easier to maintain.
     */
    public function initialize() {
        $this->addHtml('<script type="text/javascript">
        Ext.onReady(function() {
            // We could run some javascript here that runs on all of our controllers
            // for example something that loads your config
        });
        </script>');
    }
    /**
     * Defines the lexicon topics to load in our controller.
     * @return array
     */
    public function getLanguageTopics() {
        return array('namespace:default');
    }
    /**
     * We can use this to check if the user has permission to see this controller
     * @return bool
     */
    public function checkPermissions() {
        return true;
    }
}
/**
 * The Index Manager Controller is the default one that gets called when no
 * &action parameter is passed  We use it to define the default controller
 * which will then handle the actual processing.
 *
 * It is important to name this class "IndexManagerController" and making sure
 * it extends the abstract class we defined above 
 */
class IndexManagerController extends MyextraManagerController {
    /**
     * Defines the name or path to the default controller to load.
     * @return string
     */
    public static function getDefaultController() { return 'home'; }
}

<?php
/**
 * The name of the controller is based on the action (home) and the
 * namespace. This home controller is loaded by default because of
 * our IndexManagerController.
 */
class MyextraHomeManagerController extends MyextraManagerController {
    /**
     * Any specific processing we want to do here. Return a string of html.
     * @param array $scriptProperties
     */
    public function process(array $scriptProperties = array()) {
        return '<h2 class="modx-page-header">It\'s alive!</h2><p>This is your first custom manager page. You are awesome!</p>';
    }
    /**
     * The pagetitle to put in the <title> attribute.
     * @return null|string
     */
    public function getPageTitle() {
        return 'My first CMP!';
    }
    /**
     * Register needed assets. Using this method, it will automagically
     * combine and compress them if that is enabled in system settings.
     */
    public function loadCustomCssJs() {
        $this->addCss('url/to/some/css_file.css');
        $this->addJavascript('url/to/some/javascript.js');
        $this->addLastJavascript('url/to/some/javascript_load_last.js');
        $this->addHtml('<script type="text/javascript">
        Ext.onReady(function() {
            // We could run some javascript here
        });
        </script>');
    }
}