$regex = '~[.*?name=(['"])([^'"]+)1]~';
$replacements = array(
    'slider'      => slider(),
    'corusel'     => corusel(),
    'contact'     => contact(),
    'social'      => social(),
    'testimonial' => testimonial()
);

echo $content = preg_replace_callback($regex,
    function ($match) {
        global $replacements;
        $match[2];
        $key = $match[2];
        return $replacements[$key];
    },
    $content
);

function slider() {
    return $convert = require('slider.php');
}