How to replace text in Powerpoint file with Java

Question

I have a requirement where I need to replace some text in a Powerpoint File at runtime. (Powerpoint file is being used as a template with some placeholders/tokes e.g. {{USER_NAME}}) I have tried using POI but with no luck. I referred to the other links on the forum and started with 'docx4j' but am not able to go beyond a point and the documentation is not very clear (at least for me). Here is what I have done so far: Got the PPTX loaded to 'PresentationMLPackage' Got the 'MainPresentationPart' and the slides (Using mainPresentationPart.getSlide(n);)

But I am not sure of the next steps from here (or if this is the right approach in the first place).

Any suggestions will be greatly appreciated.

Thanks a Lot, -Vini

Answer 1

SlidePart extends JaxbPmlPart<Sld>
JaxbPmlPart<E> extends JaxbXmlPartXPathAware<E>
JaxbXmlPartXPathAware<E> extends JaxbXmlPart<E>

JaxbXmlPart contains:

/**
 * unmarshallFromTemplate.  Where jaxbElement has not been
 * unmarshalled yet, this is more efficient (3 times
 * faster, in some testing) than calling
 * XmlUtils.marshaltoString directly, since it avoids
 * some JAXB processing.  
 * 
 * @param mappings
 * @throws JAXBException
 * @throws Docx4JException
 * 
 * @since 3.0.0
 */
public void variableReplace(java.util.HashMap<String, String> mappings) throws JAXBException, Docx4JException {

    // Get the contents as a string
    String wmlTemplateString = null;
    if (jaxbElement==null) {

        PartStore partStore = this.getPackage().getSourcePartStore();
        String name = this.getPartName().getName();
        InputStream is = partStore.loadPart( 
                name.substring(1));
        if (is==null) {
            log.warn(name + " missing from part store");
            throw new Docx4JException(name + " missing from part store");
        } else {
            log.info("Lazily unmarshalling " + name);

            // This seems to be about 5% faster than the Scanner approach
            try {
                wmlTemplateString = IOUtils.toString(is, "UTF-8");
            } catch (IOException e) {
                throw new Docx4JException(e.getMessage(), e);
            }
        }

    } else {

        wmlTemplateString = XmlUtils.marshaltoString(jaxbElement, true, false, jc);

    }

    // Do the replacement
    jaxbElement = (E)XmlUtils.unwrap(
                        XmlUtils.unmarshallFromTemplate(wmlTemplateString, mappings, jc));

}

So once you have the slide part, you can invoke variableReplace on it. You'll need your variables to be in the format expected by XmlUtils.unmarshallFromTemplate