PDFDocument Class README

Overview

The PDFDocument class is a simple utility to generate PDF documents programmatically using Node.js. It utilizes the OpenType.js library for font management and includes basic operations like creating pages, embedding fonts, and setting font size.

Table of Contents

• Dependencies
• Class Methods
  • Constructor
  • generateBasicPDF
  • embedFont
  • setFont
  • save
• Private Methods
• Usage Example
• Error Handling
• Known Issues

Dependencies

• opentype.js: To handle and manipulate font data.
• fs: Node.js File System module, used to write the PDF data to a file.

Class Methods

Constructor

Initializes a new PDFDocument object with empty content, a default font, and a font counter.

generateBasicPDF

Generates a simple PDF with basic structure, and sets the content to "Hello, World!".

embedFont

embedFont(fontFilePath: string): Promise<void>

Asynchronously loads a TrueType font from a given file path and embeds it into the PDF.

setFont

setFont(fontName: string, fontSize: number): void

Sets the font and font size to use in the PDF.

save

save(filename: string): void

Writes the generated PDF content to a file.

Private Methods

• embedTrueTypeFont(font: opentype.Font, fontName: string): Embeds a TrueType font into the PDF.
• createStreamObject(data: ArrayBuffer): Creates a PDF object for stream data.
• createFontDescriptorObject(font: opentype.Font, fontName: string): Creates a font descriptor PDF object.
• createFontObject(...): Creates the font object with all necessary details.

Usage Example

const pdfDoc = new PDFDocument();
pdfDoc.generateBasicPDF();
pdfDoc.embedFont('path/to/font-file.ttf').then(() => {
  pdfDoc.setFont('F2', 14);
  pdfDoc.save('output.pdf');
});

Error Handling

Any errors, particularly during font loading, are logged to the console.

Known Issues

• No support for complex PDF features like images or tables.
• Only basic font manipulation supported.

Feel free to contribute and enhance its functionalities!