Add Smart File Viewer component with auto-detection and multi-format support

[widlestudiollp]

Overview

This PR adds a new Smart File Viewer custom component for Retool that automatically detects and renders multiple file types without requiring manual configuration.

It supports files from:

• Upload (local files)
• URLs (including Google Drive / Docs / Sheets / Slides)
• Base64 strings

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Features

• Auto-detection of file types (PDF, Word, Excel, CSV, JSON, images, video, text)
• Google Drive and Docs preview support via embedded URLs
• PDF viewer with pagination and navigation controls
• Word (.docx) rendering using mammoth (HTML conversion)
• Excel and CSV parsing into table view
• JSON structured preview
• Text file viewer with formatted output
• Image and video preview support
• Download, print, and clear functionality
• Responsive UI with auto height adjustment

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Technical Details

• Built using React + TypeScript
• Integrated with Retool using @tryretool/custom-component-support
• Uses:
  • react-pdf for PDF rendering
  • xlsx for Excel parsing
  • mammoth for Word document rendering
• Implements Blob URL handling for consistent file rendering
• Includes MIME detection + filename fallback for accurate file type detection
• Handles cleanup of Blob URLs to prevent memory leaks

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Fixes & Improvements

• Fixed incorrect MIME detection for .docx files (ZIP-based format issue)
• Prevented PDF rendering errors for non-PDF files
• Improved file type detection using filename fallback
• Ensured proper handling of Base64 inputs
• Stabilized rendering for multiple file formats

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Screenshots / Preview

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Notes

This component is designed to be production-ready, extensible, and reusable across Retool apps for handling various file preview use cases.

Future enhancements can include:

• Audio file support
• Drag-and-drop upload
• Improved Word rendering fidelity
• Large dataset pagination