Generating PDF file wih Phalcon

You will first need to have the mpdf library available to you (usually by composer) - https://github.com/mpdf/mpdf

In an action (that you will choose) say pdf_reportAction you gather all the data you need and inject it in a view. That will return a string which should be well formed XML. You pass that string to the mpdf library and your file is there :)

Something like this:

public function pdf_reportAction()
{
    $this->view->disable();

    // Get all the data from the database
    $data = Posts::find();   

    // Get the view data
    $html = $this->view->getRender('reports', 'pdf_report', $data);

    $pdf = new mPDF();
    $pdf->WriteHTML($html, 2);
    // .....
}

Your view will get the $data and do something with it like any view that shows data on screen. You can present things in a table or whatever you like.