How can I generate a PDF/UA compatible PDF with iText? - itext

Question

We have a number of dynamically generated printable forms files on our site that use iText 4.2.0. However, we also have a large number of users that have print disabilities and use screen readers, like JAWS, to render our PDFs. We use the .setTagged() method to tag the PDFs, but some elements of the PDF appear out of order. Some even become more jumbled after calling setTagged!
I read about PDF/UA in a 2013 interview about iText with Bruno Lowagie, and this seems like something that might help with our problem. However, I have not been able to find a good example of how to generate a PDF/UA document. Can you provide an example? Also, what is the minimum version of iText we will need to generate a PDF/UA compliant PDF document?

Answer 1

Please take a look at the PdfUA example. It explains step by step what is needed to be compliant with PDF/UA. A similar example was presented at the iText Summit in 2014 and at JavaOne. Watch the iText Summit video tutorial.
public void createPdf(String dest) throws IOException, DocumentException {
Document document = new Document(PageSize.A4.rotate());
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest));
writer.setPdfVersion(PdfWriter.VERSION_1_7);
//TAGGED PDF
//Make document tagged
writer.setTagged();
//===============
//PDF/UA
//Set document metadata
writer.setViewerPreferences(PdfWriter.DisplayDocTitle);
document.addLanguage("en-US");
document.addTitle("English pangram");
writer.createXmpMetadata();
//=====================
document.open();
Paragraph p = new Paragraph();
//PDF/UA
//Embed font
Font font = FontFactory.getFont(FONT, BaseFont.WINANSI, BaseFont.EMBEDDED, 20);
p.setFont(font);
//==================
Chunk c = new Chunk("The quick brown ");
p.add(c);
Image i = Image.getInstance(FOX);
c = new Chunk(i, 0, -24);
//PDF/UA
//Set alt text
c.setAccessibleAttribute(PdfName.ALT, new PdfString("Fox"));
//==============
p.add(c);
p.add(new Chunk(" jumps over the lazy "));
i = Image.getInstance(DOG);
c = new Chunk(i, 0, -24);
//PDF/UA
//Set alt text
c.setAccessibleAttribute(PdfName.ALT, new PdfString("Dog"));
//==================
p.add(c);
document.add(p);
p = new Paragraph("\n\n\n\n\n\n\n\n\n\n\n\n", font);
document.add(p);
List list = new List(true);
list.add(new ListItem("quick", font));
list.add(new ListItem("brown", font));
list.add(new ListItem("fox", font));
list.add(new ListItem("jumps", font));
list.add(new ListItem("over", font));
list.add(new ListItem("the", font));
list.add(new ListItem("lazy", font));
list.add(new ListItem("dog", font));
document.add(list);
document.close();
}
You make the document tagged with the setTagged document, but that's not sufficient. You also need to set document data: the document title needs to be displayed and you need to indicate the language used in the document. XMP metadata is mandatory.
Furthermore you need to embed all fonts. When you have images, you need a alternate description. In the example, we replace the words "dog" and "fox" by an image. To make sure that these images are "read out loud" correctly, we need to use the setAccessibleAttribute() method.
At the end of the example, I added a numbered list. In your duplicate question https://stackoverflow.com/questions/28222490/numbered-list-across-a-page-break-causes-jaws-to-read-numbers-out-of-order-in-it, you claim that the list is not read out loud correctly by JAWS. If you check the PDF file created with the above example, more specifically pdfua.pdf, you'll discover that JAWS reads the document as expected, with the numbers and the text in the right order.
The reason why "it doesn't work" when you try this, is simple. You claim that you are using iText, but you are not. You are using a "gork" of iText. A "gork" is an unofficial "fork" of which God Only Really Knows what's inside. You need the latest iText version to achieve what you want because PDF/UA is a standard dating from 2012 and you are using a version of iText that dates from 2009.
I suggest that you delete that other question because:
it is a duplicate of this question (if you disagree, read my answer: isn't it exactly what you're asking in both questions?),
it is off-topic in the sense that it sounds like "I am using an ancient DVD player and it doesn't want to play my blue ray disks." (I know that you downvoted my correct answer because you don't believe this to be true. So be it. Other people will find this answer valuable and understand that your vote was unfair.)
Please read the final question in The Best iText Questions on StackOverflow to find out what I think about people using unofficial, rogue, obsolete versions of iText.
See also https://stackoverflow.com/questions/25696851/can-itext-2-1-7-or-earlier-can-be-used-commercially