View PDF Document Structure View internal structure and metadata of PDF documents.

The tool works under the hood by utilizing the pdf-lib library to load and analyze PDF documents. When a PDF file is dropped into the FileDropzone component, it triggers the handleFile function, which sets off a chain of events to extract metadata from the document. This includes using getter methods like getTitle, getAuthor, and getSubject to retrieve specific information about the document. The pdf-lib library's PDFDocument.load method is used with the ignoreEncryption option set to true, allowing it to load encrypted PDFs without requiring a password.

Page information is obtained by iterating over the pages returned by the getPages method and reading their size and rotation using the getSize and getRotation methods respectively. The page dimensions are then converted from points to inches by dividing by 72, providing a more intuitive measurement for users. Form fields are discovered using the getForm and getFields methods, with error handling in place to catch cases where the PDF does not contain any forms. Creation and modification dates are formatted into human-readable strings using the toLocaleString method.

The extracted information is then organized into a tabbed interface, with three tabs for Document Info, Pages, and Form Fields. Each tab displays relevant information about the document, such as metadata, page dimensions, and form field names and types. The useState hook from React is used to manage the state of the application, storing the loaded PDF file, its structure, and any errors that may occur during processing. The useCallback hook is used to memoize functions like handleFile and reset, preventing unnecessary re-renders and improving performance. By leveraging these technologies and techniques, the tool provides a powerful and efficient way to examine and understand the internal structure of PDF documents.