[US-1143] New utility functions used in examples. (#290)

* UniPDF version updated.

* Updated examples printing PDF objects.

* Update merge and split examples.

Author: anovik

analysis/pdf_all_objects.go

@@ -12,7 +12,6 @@ import (
 	"os"
 
 	"github.com/unidoc/unipdf/v4/common/license"
-	"github.com/unidoc/unipdf/v4/core"
 	"github.com/unidoc/unipdf/v4/model"
 )
 
@@ -42,46 +41,18 @@ func main() {
 	inputPath := args[0]
 
 	fmt.Printf("Input file: %s\n", inputPath)
-	err := inspectPdf(inputPath, opt)
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-}
-
-func inspectPdf(inputPath string, opt cmdOptions) error {
 	readerOpts := model.NewReaderOpts()
 	readerOpts.Password = opt.pdfPassword
 
 	pdfReader, f, err := model.NewPdfReaderFromFile(inputPath, readerOpts)
 	if err != nil {
-		return err
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
 	}
 	defer f.Close()
-
-	objNums := pdfReader.GetObjectNums()
-
-	// Output.
-	fmt.Printf("%d PDF objects:\n", len(objNums))
-	for i, objNum := range objNums {
-		obj, err := pdfReader.GetIndirectObjectByNumber(objNum)
-		if err != nil {
-			return err
-		}
-		fmt.Println("=========================================================")
-		fmt.Printf("%3d: %d 0 %T\n", i, objNum, obj)
-		if stream, is := obj.(*core.PdfObjectStream); is {
-			decoded, err := core.DecodeStream(stream)
-			if err != nil {
-				return err
-			}
-			fmt.Printf("Decoded:\n%s\n", decoded)
-		} else if indObj, is := obj.(*core.PdfIndirectObject); is {
-			fmt.Printf("%T\n", indObj.PdfObject)
-			fmt.Printf("%s\n", indObj.PdfObject.String())
-		}
-
+	err = pdfReader.PrintPdfObjects(os.Stdout)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
 	}
-
-	return nil
 }

analysis/pdf_get_object.go

@@ -13,7 +13,6 @@ import (
 	"strconv"
 
 	"github.com/unidoc/unipdf/v4/common/license"
-	"github.com/unidoc/unipdf/v4/core"
 	"github.com/unidoc/unipdf/v4/model"
 )
 
@@ -46,48 +45,15 @@ func main() {
 	}
 
 	fmt.Printf("Input file: %s\n", inputPath)
-	err := inspectPdfObject(inputPath, objNum)
+	pdfReader, f, err := model.NewPdfReaderFromFile(inputPath, nil)
 	if err != nil {
 		fmt.Printf("Error: %v\n", err)
 		os.Exit(1)
 	}
-}
-
-func inspectPdfObject(inputPath string, objNum int) error {
-	pdfReader, f, err := model.NewPdfReaderFromFile(inputPath, nil)
-	if err != nil {
-		return err
-	}
 	defer f.Close()
-
-	// Print trailer
-	if objNum == -1 {
-		trailer, err := pdfReader.GetTrailer()
-		if err != nil {
-			return err
-		}
-
-		fmt.Printf("Trailer: %s\n", trailer.String())
-		return nil
-	}
-
-	obj, err := pdfReader.GetIndirectObjectByNumber(objNum)
+	err = pdfReader.PrintPdfObject(os.Stdout, objNum)
 	if err != nil {
-		return err
-	}
-
-	fmt.Printf("Object %d: %s\n", objNum, obj.String())
-
-	if stream, is := obj.(*core.PdfObjectStream); is {
-		decoded, err := core.DecodeStream(stream)
-		if err != nil {
-			return err
-		}
-		fmt.Printf("Decoded:\n%s", decoded)
-	} else if indObj, is := obj.(*core.PdfIndirectObject); is {
-		fmt.Printf("%T\n", indObj.PdfObject)
-		fmt.Printf("%s\n", indObj.PdfObject.String())
+		fmt.Printf("Error: %v\n", err)
+		os.Exit(1)
 	}
-
-	return nil
 }

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/unidoc/globalsign-dss v0.0.0-20220330092912-b69d85b63736
 	github.com/unidoc/pkcs7 v0.3.0
 	github.com/unidoc/unichart v0.5.1
-	github.com/unidoc/unipdf/v4 v4.3.0
+	github.com/unidoc/unipdf/v4 v4.4.0
 	golang.org/x/crypto v0.41.0
 	golang.org/x/image v0.30.0
 	golang.org/x/text v0.28.0

go.sum

@@ -136,6 +136,8 @@ github.com/unidoc/unichart v0.5.1 h1:qnYavwBV5sg9NUF59KbMOqJdh2kA454nVxdDTPPtSz8
 github.com/unidoc/unichart v0.5.1/go.mod h1:/8yJsL49OqBOyG53JFVZOwwDXDquo/ZRMkfz9fNsVgc=
 github.com/unidoc/unipdf/v4 v4.3.0 h1:eA4zjRHTULtV5thy3MausfFYDP1i59qGdsfxe709oUY=
 github.com/unidoc/unipdf/v4 v4.3.0/go.mod h1:oR0EX7TmS7KaAuzFQPA9t9HjbU4f2NbWMvzXNqtXo70=
+github.com/unidoc/unipdf/v4 v4.4.0 h1:JvfRBjQgaT1FkdUiZXmrGLp5RFhk9GB/NfHEzsiU4i0=
+github.com/unidoc/unipdf/v4 v4.4.0/go.mod h1:oR0EX7TmS7KaAuzFQPA9t9HjbU4f2NbWMvzXNqtXo70=
 github.com/unidoc/unitype v0.5.1 h1:UwTX15K6bktwKocWVvLoijIeu4JAVEAIeFqMOjvxqQs=
 github.com/unidoc/unitype v0.5.1/go.mod h1:3dxbRL+f1otNqFQIRHho8fxdg3CcUKrqS8w1SXTsqcI=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=

pages/pdf_merge.go

@@ -13,7 +13,7 @@ import (
 	"os"
 
 	"github.com/unidoc/unipdf/v4/common/license"
-	"github.com/unidoc/unipdf/v4/model"
+	"github.com/unidoc/unipdf/v4/pdfutil"
 )
 
 func init() {
@@ -47,56 +47,12 @@ func main() {
 		inputPaths = append(inputPaths, arg)
 	}
 
-	err := mergePdf(inputPaths, outputPath)
+	// Merge pdfs without forms.
+	err := pdfutil.MergePdf(inputPaths, outputPath, false)
 	if err != nil {
 		fmt.Printf("Error: %v\n", err)
 		os.Exit(1)
 	}
 
 	fmt.Printf("Complete, see output file: %s\n", outputPath)
 }
-
-func mergePdf(inputPaths []string, outputPath string) error {
-	pdfWriter := model.NewPdfWriter()
-
-	for _, inputPath := range inputPaths {
-		pdfReader, f, err := model.NewPdfReaderFromFile(inputPath, nil)
-		if err != nil {
-			return err
-		}
-		defer f.Close()
-
-		numPages, err := pdfReader.GetNumPages()
-		if err != nil {
-			return err
-		}
-
-		for i := 0; i < numPages; i++ {
-			pageNum := i + 1
-
-			page, err := pdfReader.GetPage(pageNum)
-			if err != nil {
-				return err
-			}
-
-			err = pdfWriter.AddPage(page)
-			if err != nil {
-				return err
-			}
-		}
-	}
-
-	fWrite, err := os.Create(outputPath)
-	if err != nil {
-		return err
-	}
-
-	defer fWrite.Close()
-
-	err = pdfWriter.Write(fWrite)
-	if err != nil {
-		return err
-	}
-
-	return nil
-}