joomla component not calling any model function and controller function - php

Question

I am sending a ajax request in function and calling model function but model function not calling and i also try a local controller function but not call any local function
controller
<?php
defined('_JEXEC') or die;
jimport('joomla.application.component.controller');
class IgalleryController extends JControllerLegacy
{
function __construct($config = array())
{
$config['base_path'] = JPATH_SITE.'/components/com_igallery';
parent::__construct($config);
}
function ajaxrequest()
{
//JModelLegacy::addIncludePath(JPATH_SITE . '/components/com_igallery/models', 'category');
//echo $db = JFactory::getDBO();
$model = $this->getModel('category');
$this->params = JComponentHelper::getParams('com_igallery');
$this->source = JRequest::getCmd('igsource', 'component');
//
$igid = JFactory::getApplication()->input->get('igid');
$Itemid = JFactory::getApplication()->input->get('Itemid');
$this->catid = JRequest::getInt('igid', 0);
$this->category = $model->getCategory($this->catid);
$profileId = JRequest::getInt('igpid', 0);
$profileId = $profileId == 0 ? $this->category->profile : $profileId;
$user = JFactory::getUser();
//print_r($user); die;
$this->profile = $model->getProfile($profileId);
$searchChildren = JRequest::getInt('igchild', 0);
$tags = JRequest::getVar('igtags', '');
//
$limit = JRequest::getInt('iglimit', 0);
$limit = $limit == 0 ? 1000 : $limit;
$foo = $this->foo();
print_r($foo);
$this->photoList = $model->getCategoryImagesList($this->profile, $this->catid, $tags, $searchChildren, $limit);
//
print_r($this->photoList);
}
function $this->foo()
{
return true;
}
...
in above code also print $foo variable but not get true or 1 value;

Answer 1

You must override function getModel() in your controller
parent model has construct:
public function getModel($name = '', $prefix = '', $config = array('ignore_request' => true))
You lacked $prefix and you also add include path of the model file if necessary
Regarding issue return value true of false, you must echo 1 for true of 0 for false and stop the process by die function. The return method will show so much html of joomla page.
function $this->foo()
{
echo 1;
die;
}