Get XMP Metadata

This guide will show you how to get pdf XMP meta data from a pdf file.

Before you begin #

You should get your API key from your UniCloud account.

If this is your first time using UniPDF SDK, follow this guide to set up a local development environment.

Project setup #

Clone the project repository #

In your terminal, clone examples repository. It contains the Go code we will be using for this guide.

git clone https://github.com/unidoc/unipdf-examples.git

Navigate to the metadata folder in the unipdf-examples directory.

cd unipdf-examples/metadata

Configure environment variables #

Replace the UNIDOC_LICENSE_API_KEY with your API credentials from your UniCloud account.

Linux/Mac #

export UNIDOC_LICENSE_API_KEY=PUT_YOUR_API_KEY_HERE

Windows #

set UNIDOC_LICENSE_API_KEY=PUT_YOUR_API_KEY_HERE

How it works #

The import section in lines 3-13 imports unipdf packages and other necessary libraries.

The init function in lines 15-22 loads your metered License API key from system environment prior to using the library. This authenticates your request.

In lines 24-90 the main function is defined. The input file is parsed from the command line argument in lines 25-30. In lines 33-37 the time taken to finish the process is measured. In lines 40-44 a new reader object is constructed form the input file.

The XMP metadata is extracted from the pdf catalog metadata in lines 47-50. In lines 53-56 the stream object is retrieved from XMP metadata objects. The XMP document is loaded in line 59-62. The code in lines 66-70 gets the pdf info using xmpDoc.GetPdfInfo(). The pdf info dictionary is extracted in lines 72-80. Finally in lines 82-90 the pdf version and the copy right information are extracted and printed.

Run the code #

go run pdf_get_xmp_pdf_metadata.go <input.pdf>