Mofilo Content Filter #

A comprehensive, military-grade content filtering package for Flutter that protects your app from offensive, inappropriate, and harmful content.

Features #

• Multi-layer Detection: 12+ detection layers to catch sophisticated bypass attempts
• Multi-language Support: Filters offensive content in English, Spanish, French, German, Polish, Russian, Portuguese, Italian, Dutch
• Advanced Normalization: Catches l33tspeak, Unicode tricks, zero-width characters, emojis, and visual lookalikes
• Bypass Prevention: Detects encoding (Base64, ROT13, Hex, reversed text), spacing tricks, and character substitution
• Security Protection: Blocks SQL injection, XSS, and other attack patterns
• Comprehensive Coverage: Filters profanity, slurs, hate speech, violence, sexual content, self-harm, and more
• Fuzzy Matching: Uses Levenshtein distance to catch misspellings and variations
• Context-Aware: Analyzes combined text to catch context-based violations

Installation #

Add this to your package's pubspec.yaml file:

dependencies:
  mofilo_content_filter: ^0.0.1

Usage #

Basic Usage #

import 'package:mofilo_content_filter/mofilo_content_filter.dart';

// Validate a single field
final result = ContentFilter.validateFoodName("apple");
if (result.isAllowed) {
  print("Content is safe!");
} else {
  print("Blocked: ${result.reason}");
  print("Violations: ${result.violations}");
  print("Severity: ${result.severity}");
}

Validate Multiple Fields #

// Validate food name and brand together
final results = ContentFilter.validateAll(
  foodName: "chocolate cake",
  brandName: "Generic Brand",
);

if (results.isEmpty) {
  print("All content is safe!");
} else {
  results.forEach((field, result) {
    print("$field blocked: ${result.reason}");
  });
}

Custom Validation #

// Validate with custom fields
final result = ContentFilter.filter(
  foodName: "pizza",
  brandName: "Pizza Hut",
);

if (!result.isAllowed) {
  // Handle blocked content
  showError(result.reason);
}

What Gets Blocked #

The filter detects and blocks:

Language-Based #

• Profanity and vulgar language (multiple languages)
• Racial, ethnic, and religious slurs
• Homophobic and transphobic slurs
• Sexist and misogynistic language
• Ableist slurs

Threat-Based #

• Violence and death threats
• Terrorism and extremism
• Hate speech and symbols
• Nazi/white supremacy content
• Holocaust denial

Harmful Content #

• Self-harm and suicide encouragement
• Child abuse and pedophilia references
• Sexual content and harassment
• Drug references
• Animal abuse

Technical Attacks #

• SQL injection attempts
• XSS (Cross-Site Scripting)
• Spam and gibberish patterns
• Encoded malicious content (Base64, ROT13, etc.)

Bypass Techniques Defended Against #

1. Character Substitution: l33tspeak (f0ck, sh1t), symbols (@ss, f*ck)
2. Spacing/Separators: f.u.c.k, f-u-c-k, f u c k
3. Unicode Tricks: Cyrillic (фuck), fullwidth (ｆｕｃｋ), circled (ⓕⓤⓒⓚ)
4. Zero-Width Characters: fu​‌‍ck (invisible chars)
5. Emojis: f😀u😀c😀k
6. Encoding: Base64, ROT13, Hex, reversed text
7. Mixed Case: FuCk, FUCK, fUcK
8. Asterisks: fk, ner
9. Homoglyphs: Using visually similar characters
10. Fuzzy Spelling: fck, fuk, fuuk (Levenshtein distance matching)

Result Object #

class ContentFilterResult {
  final bool isAllowed;          // Whether content passes filter
  final String? reason;           // Reason for blocking (if blocked)
  final List<String> violations;  // List of specific violations
  final ContentFilterSeverity severity; // Severity level
}

enum ContentFilterSeverity {
  none,      // Content is safe
  low,       // Suspicious but might be legitimate
  medium,    // Likely violation
  high,      // Definite violation
  critical,  // Severe violation (slurs, hate speech, CSAM)
}

Publishing Checklist #

Before publishing to pub.dev:

1. Update homepage/repository URLs in pubspec.yaml
2. Ensure all tests pass: flutter test
3. Check package score: flutter pub publish --dry-run
4. Update CHANGELOG.md with version notes
5. Publish: flutter pub publish

Contributing #

Contributions are welcome! Please:

1. Test thoroughly with edge cases
2. Follow existing code style
3. Update documentation
4. Add tests for new features

License #

[Your License Here]

Disclaimer #

This filter aims to block offensive content but no filter is 100% perfect. Always combine with human moderation for critical applications.

mofilo_content_filter #