How can I stamp text on generated PDF pages? - pdf-generation

Question

From your help I have managed to get a very nice PDF generation tool built. It builds a PDF based off of a 5 page template. On the 3rd and 5th page there is a possibility of needing additional pages added and moving the next pages down. The 5th page is landscape even. Everything works perfect except one little additional functionality that I am looking for.
The template that I have built has form fields on the fifth page. Therefore, I use the following code to fill the field:
var pdfReader = new PdfReader(existingFileStream);
var stamper = new PdfStamper(pdfReader, newFileStream);
var form = stamper.AcroFields;
form.SetField("fkClientName", clientName);
The field gets filled just fine, but not on the additional pages. Which is weird because I do call this line:
PdfImportedPage templatePage = stamper.GetImportedPage(pdfReader, 5);
I feel like it should see that there is form fields on that fifth page. However, I read that stamper.GetImportedPage does not retrieve form fields. I don't really care if it's a form field or text. I just need the client name at the top of each generated additional page. Here is what my columntext code looks like that builds the additional pages:
while (true)
{
ct.SetSimpleColumn(-75, 75, PageSize.A4.Height + 25, PageSize.A4.Width - 200);
if (!ColumnText.HasMoreText(ct.Go()))
break;
pageNum++;
stamper.InsertPage(pageNum, new Rectangle(792f, 612f));
stamper.GetOverContent(pageNum).AddTemplate(templatePage, 0, -1f, 1f, 0, 0, PageSize.A4.Width);
ct.Canvas = stamper.GetOverContent(pageNum);
}

Answer 1

If you had company stationery with some kind of background and you wanted to create a document that has flowing text (a column that can flow over to the next page) that also has a repeating header, then I would prefer using PdfWriter.
I'd use PdfWriter to add the content (without using ColumnText, just use the page size and the margins to define the column) and I would add the background and the header using page events. See for instance the Stationery example from my book.
I'd create a subclass for PdfPageEventHelper and I'd load the page you want to see repeated into a PdfImportedPage instance named page:
PdfReader reader = new PdfReader(STATIONERY);
page = writer.getImportedPage(reader, 1);
You may also want to initialize a Phrase with the name of your customer:
header = new Phrase(customerName);
Then you override the onEndPage() method like this:
public void onEndPage(PdfWriter writer, Document document) {
writer.getDirectContentUnder().addTemplate(page, 0, 0);
ColumnText.showTextAligned(writer.getDirectContent(),
Element.ALIGN_RIGHT, header, 36, 806, 0);
}
Now you don't have to worry about ColumnText and new pages. Every time a new page is created, the background and the header will be added automatically.
However, you are using PdfStamper because your original document isn't company stationery: it's a 5 page document. If this document doesn't contain any interactive elements (you've created it using iTextSharp, so you know if it's a flat document or not), I'd still try the PdfWriter approach and change the page instance in the event whenever a new page is needed.
If you want to keep on using PdfStamper, you'll have to add the header in a different way. For instance using a different ColumnText instance, or, if it's a single line, using ColumnText.showTextAligned(). If you don't know the coordinates for the header, you can retrieve the position of the field using the getFieldPositions() method.