How can you change individual words in a PDF using javascript?

Question

Hi,
I am trying to do some simple text replacement in a PDF file using Acrobat. Specifically, I want to do some simple transliteration of words or partial transliteration. For instance, I would like to change a word like "red" to "ρed". This is to help me get used to the Greek alphabet step by step.
Anyway, I downloaded Acrobat and there is no feature to do a single letter search and replace -- only word replacement. I have a Computer Science degree and decided to investigate the javascript capabilities to see if I can make those a simple letter replacement script. However, I have gotten to the point where I can cycle through every word in the PDF (using functions like getPageNthWord), and I can make a replacement on the string returned using something like: val.replace(/r/, "ρ"). However, I don't know how to replace the word in the PDF file....such as with a hypothetical function setPageNthWord (which does not exit). I have found the online documentation very thin on this, and I am scratching my head. Perhaps, it is something to do with the PDF format that I do not understand. So, is there a way to simply change text of a PDF file, like I am asking? All I am looking for is simple script to change a letter to another across a PDF.
thanks if you can help
Justin

Answer 1

JS can't edit the text in a PDF file directly. There are workarounds, like
using a redaction with overlay text or simply placing a new field or
annotation on top of the old text with the new one, but they are all far
from perfect and won't cause a "reflow" of the document, so if the two
texts are not of the same length the result will look odd. Also there's the
issue of which font to use (font family, color, size, etc.), which JS can't
know so you'll have to tell it.