<div>
    <zscript>
        import java.net.URL;
        import org.zkoss.util.media.AMedia;
        public AMedia loadPdf() {
            return new AMedia(application.getResource(execution.toAbsoluteURI("test.pdf", true)), null, null);
        }
        AMedia document = loadPdf();
    </zscript>
    pdfviewer is ignoring the content media initially
    <pdfviewer id="pdf" content="${document}"/>
    <button label="dynamic content via zkau works" onClick="pdf.setContent(loadPdf());"/>
</div>