Document Metadata Extractor

A TypeScript library for extracting metadata from various document types. This library provides a unified interface for extracting metadata from PDFs, images, Excel files, Word documents, and PowerPoint presentations.

Overview

This library is built on top of various specialized libraries to extract metadata from different document formats. Each document type uses its underlying library to parse and extract relevant metadata:

• PDF: Built on top of unpdf for extracting PDF metadata and page counts
• Images: Built on top of exiftool-vendored for extracting EXIF and image metadata
• Excel: Built on top of xlsx for extracting spreadsheet metadata, sheet information, and document properties
• DOCX/PPTX: Built on top of jszip and @xmldom/xmldom for parsing Office Open XML documents and extracting metadata from core and application properties

Installation

npm install @xcvzmoon/document-metadata-extractor
# or
pnpm add @xcvzmoon/document-metadata-extractor
# or
yarn add @xcvzmoon/document-metadata-extractor
# or
bun add @xcvzmoon/document-metadata-extractor

Usage

import { getMetadata } from '@xcvzmoon/document-metadata-extractor';
import { readFile } from 'fs/promises';

// Read a file as Buffer
const fileBuffer = await readFile('document.pdf');

// Extract metadata
const metadata = await getMetadata(fileBuffer, { target: 'pdf' });
console.log(metadata);

Supported Document Types

PDF

Extracts PDF metadata including title, author, subject, creator, producer, creation date, modification date, and page count.

const metadata = await getMetadata(pdfBuffer, { target: 'pdf' });
// Returns: PdfMetadata with pages, title, author, subject, creator, producer, creationDate, modificationDate

Images

Extracts EXIF and image metadata using ExifTool. Returns all available tags from the image file.

const metadata = await getMetadata(imageBuffer, { target: 'image' });
// Returns: All ExifTool tags for the image

Excel

Extracts spreadsheet metadata including sheet names, sheet count, row/column counts, author, last modified by, creation/modification dates, company, and file size.

const metadata = await getMetadata(excelBuffer, { target: 'excel' });
// Returns: ExcelMetadata with sheets, sheetCount, rows, columns, author, lastModifiedBy, created, modified, company, fileSize

DOCX

Extracts Word document metadata including title, subject, creator, keywords, description, last modified by, revision, creation/modification dates, category, company, page count, word count, character count, and file size.

const metadata = await getMetadata(docxBuffer, { target: 'docx' });
// Returns: DocxMetadata with title, subject, creator, keywords, description, lastModifiedBy, revision, created, modified, category, company, pageCount, wordCount, characterCount, fileSize

PPTX

Extracts PowerPoint presentation metadata using the same extraction method as DOCX files.

const metadata = await getMetadata(pptxBuffer, { target: 'pptx' });
// Returns: DocxMetadata (same structure as DOCX)

API

getMetadata(data: Buffer, options: { target: 'image' | 'pdf' | 'docx' | 'excel' | 'pptx' })

Extracts metadata from a document buffer based on the specified target type.

Parameters:

• data: A Buffer containing the document file data
• options.target: The document type to extract metadata from

Returns:

• Promise resolving to the appropriate metadata type based on the target:
  • PdfMetadata for PDF files
  • ExifTool tags object for images
  • ExcelMetadata for Excel files
  • DocxMetadata for DOCX and PPTX files

Type Definitions

The library exports TypeScript type definitions for all metadata types:

• PdfMetadata
• ExcelMetadata
• DocxMetadata

License

ISC

Author

Mon Albert Gamil - GitHub