在div中加载视图的问题 - codeigniter

I am having an issue with loading a view inside a div.

The view alone loads well, but it appears blank while loading inside the div.

partial view ---> div in a main view

Structure

Controller main view

public function main_view(){
   $data['page']="";
   $this->load->view('layouts/header');
   $data['accordion'] = $this->load->view('layouts/partial_view', '', TRUE);
   $this->load->view('site/main_view',$data);
   $this->load->view('layouts/footer');

}

Controller partial view

public function getFileType() {
$user_id = $this->session->userdata('id');
$this->load->model('portfolio_model');

$data['portfolio']=$this->portfolio_model->get_file_type($user_id);
$this->load->view('layouts/partial_view',$data);

}

Portfolio model

function get_file_type() { .... }

Main_view

<div>
    <?php echo $accordion; ?>
</div>

Partial view

<?php if($this->session->userdata('id')) {
if(isset($portfolio) && !empty($portfolio)) { ?>

**** other view html **** <?php } } ?>

The reason was the data wasn't passing to the partial view. So, I put everything in the main view.

Controller main view

public function main_view(){
   $data['page']="";
   $this->load->model('portfolio_model');
   $data['portfolio']=$this->portfolio_model->get_file_type($user_id);
   $this->load->view('layouts/header');
   //$data['accordion'] = $this->load->view('layouts/partial_view', '', TRUE); **** removed ****
   $this->load->view('site/main_view',$data);
   $this->load->view('layouts/footer');
}

Partial view controller deleted

And view content from 'partial view' is put into 'main view' , into the 'div' where i wanted it.

<div> html and php content from the partial view </div>