Example code using the Java library Apache POI (http://php-java-bridge.sourceforge.net/pjb/webapp.php) to manipulate ppt-files (PHPPowerPoint can only create, not manipulate files). Uses Java/PHP bridge (http://php-java-bridge.sourceforge.net/pjb/how_it_works.php)

phpjavabridge-apache-poi-example-code.php

<?php

require_once("http://localhost:8080/GapcmsJavaBridge/java/Java.inc");

// fake paths for gist
$sourceDataPpt = APP_PATH . "/includes/source_data.ppt";
$uploadedPpt = APP_PATH . "/upload/foo_data.ppt";

try {

    $sourceDataPpt = new java("org.apache.poi.hslf.usermodel.SlideShow", new java("org.apache.poi.hslf.HSLFSlideShow", $$sourceDataPpt));

    $ppt = new java("org.apache.poi.hslf.usermodel.SlideShow", new java("org.apache.poi.hslf.HSLFSlideShow", $uploadedPpt));

    $newSlide = $ppt->createSlide();

    $translate = array(
        '${t:DATA DOCUMENTATION}' => 'DATA DOCUMENTATION',
        '${t:Updates and translations to this file may be available here:}' => 'Updates and translations to this file may be available here:',
        '${chapter_url}' => 'http://www.gapminder.org/foo',
        '${datasource1_url}' => 'http://un.org/esa/population',
        '${datasource2_url}' => 'www.gapminder.org/data/documentation/gd003/',
    );

    foreach ($sourceDataPpt->getSlides()[0]->getShapes() as $k => $shape) {

        foreach ($shape->getTextRun()->getRichTextRuns() as $i => $rt) {

            $text = $rt->getText();

            //var_dump($k, $i, java_values($rt->getText()));

            foreach ($translate as $search => $replace) {

                if (strpos($text, $search) !== false) {
                    $text = str_replace($search, $replace, $text);
                    $rt->setText(new java("java.lang.String", $text));
                }

            }

        }

        $newSlide->addShape($shape);
    }

    //var_dump(java_values($ppt));

    // Output to browser for now
    header("Content-type: application/vnd.ms-powerpoint");
    header("Content-Disposition: attachment; filename=presentation.ppt");
    $memoryStream = new java("java.io.ByteArrayOutputStream");
    $ppt->write($memoryStream);
    $memoryStream->close();
    echo java_values($memoryStream->toByteArray());

} catch (Exception $e) {
    var_dump($e);
}