Manage PDF XMP metadata in C++

Use PdfXmpMetadata to add, update, remove, and read XMP properties and register a custom metadata namespace.

The read example expects the standard and custom keys written by AddXmpMetadata. Its outputFile is a text report rather than a modified PDF.

The snippets are independent example functions with their SDK includes and example namespaces. Configure the Aspose.PDF for C++ SDK, supply the input resources referenced by the sample, and choose writable output paths. The examples retain the source field names, page indexes, coordinates, and options.

PdfXmpMetadata workflows

• Add XMP metadata
• Get XMP metadata

Add XMP metadata

Set standard timestamps and creator tool, remove ModifyDate, and register and update a custom property.

1. Create PdfXmpMetadata.
2. Bind the PDF input with Facade::BindPdf().
3. Add the XMP property with PdfXmpMetadata::Add().
4. Remove the XMP property with PdfXmpMetadata::Remove().
5. Register the custom namespace with PdfXmpMetadata::RegisterNamespaceURI().
6. Update the metadata value with PdfXmpMetadata::idx_set().
7. Save the resulting PDF with PdfXmpMetadata::Save().

#include <Aspose.PDF.Cpp/Data/XMP/XmpValue.h>
#include <Aspose.PDF.Cpp/Facades/DefaultMetadataProperties.h>
#include <Aspose.PDF.Cpp/Facades/PdfXmpMetadata.h>
#include <system/date_time_offset.h>
#include <system/string.h>

namespace Facades::Examples::PDF_XmpMetaData
{
	using namespace System;
	using namespace Aspose::Pdf;
	using namespace Aspose::Pdf::Facades;

	void AddXmpMetadata(String inputFile, String outputFile)
	{
		auto xmp = MakeObject<PdfXmpMetadata>();
		xmp->BindPdf(inputFile);
		auto timestamp = MakeObject<XmpValue>(DateTimeOffset::get_UtcNow().ToString(u"o"));
		xmp->Add(DefaultMetadataProperties::CreateDate, timestamp);
		xmp->Add(DefaultMetadataProperties::MetadataDate, timestamp);
		xmp->Add(DefaultMetadataProperties::CreatorTool, MakeObject<XmpValue>(u"Creator tool name"));
		xmp->Remove(DefaultMetadataProperties::ModifyDate);
		xmp->RegisterNamespaceURI(u"customNamespace", u"http://www.customNameSpaces.com/ns/");
		xmp->Add(u"customNamespace:UserPropertyName", MakeObject<XmpValue>(u"UserPropertyValue"));
		xmp->idx_set(u"customNamespace:UserPropertyName", MakeObject<XmpValue>(u"UserPropertyValue2"));
		xmp->Save(outputFile);
	}
} // namespace Facades::Examples::PDF_XmpMetaData

Get XMP metadata

Read expected standard and custom XMP keys, print them, and write a text report.

1. Create PdfXmpMetadata.
2. Bind the PDF input with Facade::BindPdf().
3. Read the metadata value with PdfXmpMetadata::idx_get().
4. Write the collected values to the output text file.

#include <Aspose.PDF.Cpp/Data/XMP/XmpValue.h>
#include <Aspose.PDF.Cpp/Facades/DefaultMetadataProperties.h>
#include <Aspose.PDF.Cpp/Facades/PdfXmpMetadata.h>
#include <iostream>
#include <system/io/file.h>
#include <system/io/file_stream.h>
#include <system/string.h>

namespace Facades::Examples::PDF_XmpMetaData
{
using namespace System;
using namespace Aspose::Pdf;
using namespace Aspose::Pdf::Facades;

void GetXmpMetadata(String inputFile, String outputFile)
{
    auto xmp = MakeObject<PdfXmpMetadata>();
    xmp->BindPdf(inputFile);
    String report;
    for (auto key : {DefaultMetadataProperties::CreateDate, DefaultMetadataProperties::MetadataDate,
                     DefaultMetadataProperties::CreatorTool})
        report += xmp->idx_get(key)->ToString() + u"\n";
    report += xmp->idx_get(u"customNamespace:UserPropertyName")->ToString() + u"\n";
    std::cout << report << std::endl;
    System::IO::File::WriteAllText(outputFile, report);
}
} // namespace Facades::Examples::PDF_XmpMetaData