ob_start буфер

footer-webim.php

# https://phpfashion.com/everything-about-output-buffering-in-php
ob_start();  // turns on output buffering
    {   
       # $foo->render();  // output goes only to buffer
        $output = ob_get_contents();  // stores buffer contents to the variable
    }
    ob_end_clean();  // clears buffer and closes buffering