Add document preview

[MaryammAli]

Here’s a clean and professional README you can use for this feature:

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📄 Document Preview Service

📌 Overview

The Document Preview Service enables users to preview uploaded documents directly within the application without needing to download them first. It supports multiple file types including PDFs and images, and provides a seamless viewing experience with an optional download feature.

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✨ Features

• PDF Preview

  • View PDF documents directly in the browser.
  • Supports multi-page navigation.

• Image Preview

  • Preview common image formats (JPG, PNG, etc.).
  • Optimized for fast loading and responsive display.

• Document Viewer

  • Unified interface for viewing supported document types.
  • Clean and user-friendly UI for easy interaction.

• Download Option

  • Users can download original files at any time.
  • Ensures accessibility and offline usage.

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🛠️ Implementation Details

• Handles file rendering based on type:

  • PDF → embedded viewer
  • Images → inline display

• Secure file access and delivery

• Scalable architecture to support additional formats in the future

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📂 Project Structure

src/
 └── modules/
      └── documents/
           ├── controllers/
           ├── services/
           ├── utils/
           └── viewers/

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🚀 Usage

Preview a Document

GET /documents/:id/preview

Download a Document

GET /documents/:id/download

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✅ Acceptance Criteria

• PDF preview is supported
• Image preview is supported
• Document viewer is implemented
• Download option is available

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🔐 Security Considerations

• Access control for document viewing
• Validation of file types
• Protection against unauthorized downloads

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🧪 Testing

• Tested PDF rendering across multiple files
• Verified image previews for different formats
• Confirmed download functionality
• Checked performance with large files

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⚠️ Notes

• Ensure proper MIME type handling
• Large documents may require lazy loading or pagination
• Future support can include DOCX and other formats

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📷 (Optional)

Add screenshots or demo links showing:

• PDF preview interface
• Image preview
• Document viewer UI

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If you want, I can also make a more developer-focused README (with setup, dependencies, and libraries like PDF.js) or a short version for GitHub.
Closes #400
Closes #399
Closes #398
Closes #397