aim_server_multipart 0.0.1

Multipart form data parsing for aim_server framework. Supports multipart/form-data format.

0.0.1

Initial release of aim_server_multipart - Multipart form data parser for the Aim framework.

Features

• Multipart/Form-Data Parsing: RFC 7578 compliant parser for handling file uploads and form data
• File Upload Support:
  • Single file uploads
  • Multiple file uploads with same field name
  • Mixed text fields and files in same request
• Security Features:
  • Automatic filename sanitization to prevent path traversal attacks
  • Random unique filename generation to prevent collisions
  • Original filename preserved for reference
• Validation Options:
  • maxFileSize - Limit individual file size
  • maxTotalSize - Limit total upload size
  • allowedMimeTypes - Filter by MIME type with wildcard support (image/*)
• Efficient Processing:
  • Stream-based processing for memory efficiency
  • Real-time size validation during upload
  • Optimized with BytesBuilder for large files
• Developer Experience:
  • Type-safe API using Dart 3 Records
  • Clean and intuitive API (form.file(), form.field())
  • Comprehensive error handling with FormatException and Exception
  • Well-documented with examples

API

• MultipartFormData class for accessing parsed data
  • field(String name) - Get single text field
  • fields(String name) - Get multiple fields
  • file(String name) - Get single file
  • files(String name) - Get multiple files
  • has(String name) - Check field/file existence
• UploadedFile class representing uploaded files
  • filename - Sanitized safe filename
  • originalFilename - Original client filename
  • contentType - MIME type
  • bytes - File content
  • size - File size
  • saveTo(String path) - Save to disk
  • asString([Encoding]) - Read as string
• Request extension with multipart() method

Testing

• 39 comprehensive tests covering:
  • Filename sanitization and security
  • File size validation (per-file and total)
  • MIME type filtering with wildcards
  • Multiple files and fields
  • Error handling
  • Edge cases (special characters, Unicode, etc.)

Supported

• Dart SDK: ^3.10.0
• Dependencies:
  • aim_server: ^0.0.5
  • mime: ^2.0.0

Security Considerations

This package implements several security measures by default:

• Path traversal prevention (blocks ../, absolute paths)
• Filename sanitization (removes dangerous characters)
• Unique filename generation (prevents overwrites)
• Size limits enforcement
• MIME type validation

What's Next

Future versions may include:

• Streaming file saves for very large files
• Custom sanitization strategies
• Progress callbacks for upload tracking
• Character encoding detection and conversion