Add Side Note to a Page’s Margin

Add a sidenote to a page’s left or right margin using the .PageFinalize function while creating the PDF.

The .pageFinalize function is called on each PDF page in the final stage of creation and appends a paragraph at 90 degrees with custom text.

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 the examples repository. It contains the Go code we will be using for this guide.

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

Change into the repository directory and navigate to the pages folder.

cd unipdf-examples/pages

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 #

Lines 9-17 import the UniPDF packages and other required dependencies.

Lines 19-26 authenticate your request with your UNIDOC_LICENSE_API_KEY with the init function.

The main function in lines 28-102 creates a new PDF, appending a sidenote to each page margin. The created PDF is saved to the output path, page_side_notes.pdf.

Run the code #

Run this command to add a sidenote to each page’s margin. This will also get all the required dependencies to run the program.

go run pdf_page_side_note.go

Sample output #

There is text on each page’s left or right margin in the PDF. In this example, you can see the text: Page 1/2 at the page’s right margin.