feat: Add CSV & PDF Export Functionality (#681)

[komalharshita]

📋 Summary

Implements CSV and PDF export functionality for expenses with advanced filtering options.

🎯 Changes Made

• ✅ Added export modal event listeners and handlers
• ✅ Implemented quick export (CSV & PDF) without filters
• ✅ Implemented advanced export with date range and category filters
• ✅ Added live export preview with statistics
• ✅ Integrated with existing backend /api/expenses/export endpoint
• ✅ Added responsive export modal styling
• ✅ Download functionality with proper file naming

🔧 Technical Details

Frontend (trackerscript.js):

• openExportModal() - Opens export modal with default filters
• exportData(format) - Main export function
• quickExportCSV() - Quick CSV export (all time)
• quickExportPDF() - Quick PDF export (all time)
• updateExportPreview() - Live preview with stats
• Event listeners for all export buttons and filters

Backend Integration:

• Uses existing POST /api/expenses/export endpoint
• Supports format: csv, pdf, excel
• Filters: startDate, endDate, category, type
• Returns file blob for download

UI/UX Features:

• 3 export buttons: Quick CSV, Quick PDF, Advanced Export
• Export modal with format selection (CSV/PDF)
• Date range picker
• Category and type filters
• Live preview showing:
  • Total transactions count
  • Total income
  • Total expenses
  • Net balance
• Auto-download with timestamped filenames
• Loading states and error handling
• Success/error notifications

🧪 Testing

• Quick CSV export works
• Quick PDF export works
• Advanced export modal opens/closes
• Date filters work correctly
• Category/type filters work
• Export preview updates live
• File downloads with correct name
• Error handling works
• Mobile responsive design
• Works with authentication

⚠️ Breaking Changes

None - fully backward compatible

📚 Dependencies

No new dependencies added. Uses existing:

• Backend: exportService (already implemented)
• Backend: pdfkit (already installed)
• Backend: exceljs (already installed)

✅ Checklist

• Code follows project style guidelines
• Self-review completed
• No console errors
• Works on desktop and mobile
• All export buttons functional
• Backend API integration working
• Error handling implemented
• User notifications added

🔗 Related Issues

Closes #681

🙏 Acknowledgments

Thanks to @Renu-code123 for the amazing ExpenseFlow project!

[vercel]

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[github-actions]

🎉 Thanks for the PR, @komalharshita!

We really appreciate you taking the time to contribute to ExpenseFlow! 💙

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✅ PR Checklist

Before we review, please ensure:

• Your code follows the project's coding standards
• All file changes are accurate and intentional
• You've tested your changes locally
• Any review comments have been addressed

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🙌 Thank You for Contributing!

We truly appreciate your interest in contributing to this project.

• Please make sure your code follows the project structure
• Add clear commit messages and comments where necessary
• Ensure your changes do not break existing functionality

We'll review your PR as soon as possible. Keep up the great work! ✨

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[komalharshita]

this pr is meant as a L2 or L3 level contribution

[vercel]

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Project	Deployment	Actions	Updated (UTC)
expenseflow	Ready	Preview, Comment	Feb 19, 2026 0:53am

[Renu-code123]

@komalharshita, hey, I don't assign a level for ECWOC; it's automatically assigned by the ECWOC bot, which gives a level by analyzing the code.