main.go

package main

import (
	"fmt"

	. "github.com/pdftron/pdftron-go/v2"
)

const filename = "PDFTRON-test-pdf.pdf"
const beeFilename = "bee-movie-script.pdf"

type Sentences struct {
	stringSentence string
	metadata       string
}

func main() {

	PDFNetInitialize("demo:1681479144517:7df72d550300000000cd5af736e910cc63e454cadb25e0d06c2b7147ee")

	// open document from the filesystem
	doc := NewPDFDoc(filename)

	// Printing the filename
	fmt.Println(doc.GetFileName())

	doc.Close()

	//Read text from a file example from - https://docs.apryse.com/documentation/linux/guides/features/extraction/text-extract/
	readTextFromFile()

	//Read text from a file on a sentence basis.
	readTextOnASentenceBasis()

	// Converting txt file
	openTXTFile()
}

func readTextFromFile() {
	doc := NewPDFDoc(filename)
	page := doc.GetPage(1)

	txt := NewTextExtractor()
	txt.Begin(page) // Readspage

	// Extract words one by one
	word := NewWord()
	line := txt.GetFirstLine()
	for line.IsValid() {
		word = line.GetFirstWord()
		for word.IsValid() {
			// to get words in string you need to call .GetString() on a "word".
			fmt.Println("This is the current word: ", word.GetString())
			word = word.GetNextWord()
		}
		// To see new lines not needed
		fmt.Println()
		line = line.GetNextLine()
	}

	doc.Close()
}

func readTextOnASentenceBasis() {
	var sentence string
	var wordString string
	var finalCharInWord string

	doc := NewPDFDoc(beeFilename)
	page := doc.GetPage(1)

	txt := NewTextExtractor()
	txt.Begin(page) // Readspage

	// Extract words one by one
	word := NewWord()
	line := txt.GetFirstLine()
	for line.IsValid() {
		word = line.GetFirstWord()
		for word.IsValid() {
			// to get words in string you need to call .GetString() on a "word".
			wordString = word.GetString()

			// Append word to sentence (it is possible to use bytes pgk to do it in O(n) time)
			// https://stackoverflow.com/questions/1760757/how-to-efficiently-concatenate-strings-in-go)
			sentence += wordString + " "

			// This can probably be done a lot prettier.
			finalCharInWord = string(wordString[len(wordString)-1])

			// Check to see if there is punctuation to see if there is a sentence.
			if finalCharInWord == "." || finalCharInWord == "?" || finalCharInWord == "!" {
				fmt.Println("Final sentence: ", sentence)
				sentence = ""
			}

			word = word.GetNextWord()
		}
		line = line.GetNextLine()
	}

	doc.Close()

}

func openTXTFile() {

	doc := NewPDFDoc()
	txtFile := "pdftron-txt-file.txt"

	// Converting txt to pdf. Maybe a bit overkill to convert .txt to pdf.
	ConvertFromText(doc, txtFile)

	// The second argument is a bitwise disjunction of flags used as options during serialization.
	doc.Save("pdftron-txt-to-pdf-file.pdf", uint(SDFDocE_remove_unused))
}