Hotwire Series: Drag & Drop File Upload Using Stimulus Controllers - Part 6

  • Date5/6/2025
  • Reading Time7 min
Hotwire Series: Drag & Drop File Upload Using Stimulus Controllers - Part 6

Introduction

  • Modern file upload expectations
  • The limitations of traditional file inputs
  • How Stimulus enhances the upload experience

Basic Setup for File Uploads

  • Creating the file upload form
  • Setting up ActiveStorage in Rails 8
  • Basic styling for the upload area

Building a Stimulus Controller for Drag & Drop

  • Controller structure and lifecycle hooks
  • Handling drag events (dragover, dragenter, dragleave)
  • Processing the drop event

Enhancing the User Experience

  • Visual feedback during drag operations
  • Preview generation for different file types
  • Validating files before upload

Direct Uploads to Cloud Storage

  • Configuring ActiveStorage for direct uploads
  • Setting up progress tracking
  • Handling upload success and failure

Progress Indicators and Cancel Functionality

  • Creating a progress UI component
  • Updating progress in real-time
  • Implementing cancel functionality

Multiple File Upload Handling

  • Managing collections of files
  • Batch processing uploads
  • Reordering uploaded files

Integration with Image Processing

  • Creating thumbnails and previews
  • Handling different image formats
  • Image optimization techniques

Advanced Features

  • Chunked uploads for large files
  • Resume functionality for interrupted uploads
  • Background processing of uploaded files

Security Considerations

  • Validating file types and content
  • Scanning for malicious files
  • Authorization for upload actions

Testing Upload Functionality

  • Unit tests for the Stimulus controller
  • Integration tests for the upload flow
  • Testing failure scenarios and recovery

Conclusion

  • Best practices for file uploads
  • Performance optimization tips
  • Further enhancements to consider

Code Repository

  • Link to the example upload implementation
  • Configuration and customization documentation

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