List Annotations in a PDF

This guide will show you how to get all the annotations on each page in a PDF document.

Sample Input #

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.

Clone the project repository #

In your terminal, clone the 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 extract folder in the unipdf-examples directory.

cd unipdf-examples/extract

How it works #

Lines 9-15 import the UniPDF packages and other required dependencies.

The init function in lines 17-24 authenticates your request with your UNIDOC_LICENSE_API_KEY.

The main function in lines 26-39 validates your input and passes it as an argument to the listAnnotations function.

Lines 41-80 define the listAnnotations function, which accepts inputPath as a parameter. The function reads the input PDF with the pdfReader method and gets the annotations for each page with getAnnotations() function.

The printAnnotations function in lines 69-73 returns all annotations for each page in the PDF to the terminal.

Run the code #

Run this command to list the annotations per page in a PDF. This will also get all the required dependencies to run the program.

go run pdf_list_annotations.go input.pdf input2.pdf ...

Sample output #

You will get a list of annotations per page in the PDF on the terminal.

-- Page 1
 1. *model.PdfAnnotationSquare: Dict("Type": Annot, "Rect": [139, 450, 199, 490], "AP": Dict("N": Ref(15 0), ), "C": [0, 0, 0], )