🚀 FormStack - Dynamic Form Builder for Flutter

The most powerful and flexible form builder for Flutter applications. Create dynamic, responsive forms with minimal code using JSON or Dart objects.

✨ Why Choose FormStack?

• 🎯 20+ Input Types - From simple text fields to complex map location pickers
• 🎨 Multiple Styles - Beautiful, customizable UI components
• 📱 Responsive Design - Works perfectly on all screen sizes
• 🔧 JSON or Dart - Build forms using JSON files or Dart objects
• ⚡ High Performance - Optimized for smooth user experience
• 🛡️ Built-in Validation - Comprehensive validation with custom error messages
• 🧩 Modular Architecture - Easy to extend and customize
• 💾 Memory Efficient - No memory leaks, proper resource management

🎬 Quick Demo

import 'package:formstack/formstack.dart';

// Create a form in just a few lines!
FormStack.api().form(
  steps: [
    InstructionStep(
      title: "Welcome!",
      text: "Let's get started with your information",
    ),
    QuestionStep(
      title: "Your Name",
      inputType: InputType.name,
      id: GenericIdentifier(id: "name"),
    ),
    QuestionStep(
      title: "Email Address",
      inputType: InputType.email,
      id: GenericIdentifier(id: "email"),
    ),
    CompletionStep(
      title: "Thank You!",
      text: "Your information has been submitted",
    ),
  ],
).render();

📦 Installation

Add FormStack to your pubspec.yaml:

dependencies:
  formstack: ^latest_version

Then run:

flutter pub get

🚀 Quick Start

1. Basic Form Setup

import 'package:flutter/material.dart';
import 'package:formstack/formstack.dart';

class MyForm extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: FormStack.api().form(
        steps: [
          QuestionStep(
            title: "What's your name?",
            inputType: InputType.name,
            id: GenericIdentifier(id: "name"),
          ),
          QuestionStep(
            title: "Enter your email",
            inputType: InputType.email,
            id: GenericIdentifier(id: "email"),
          ),
        ],
      ).render(),
    );
  }
}

2. Load from JSON

// Load form from JSON file
await FormStack.api().loadFromAsset('assets/my_form.json');

// Render the form
FormStack.api().render()

🎨 Available Input Types

📝 Text Inputs

• Email - Email validation with regex
• Name - Name validation (letters only)
• Password - Secure password input
• Text - Multi-line text input
• Number - Numeric input with validation

📅 Date & Time

• Date - Date picker
• Time - Time picker
• DateTime - Combined date and time picker

✅ Choice Inputs

• Single Choice - Radio button selection
• Multiple Choice - Checkbox selection
• Dropdown - Traditional dropdown menu

🎯 Special Inputs

• OTP - One-time password input
• Smile Rating - 1-5 star rating slider
• File Upload - File picker with filters
• Dynamic Key-Value - Custom key-value pairs
• HTML Editor - Rich text editor
• Map Location - Interactive map picker
• Avatar - Circular image upload
• Banner - Rectangular image upload

🎨 Styling Options

Component Styles

QuestionStep(
  title: "Styled Input",
  inputType: InputType.text,
  componentsStyle: ComponentsStyle.basic, // or ComponentsStyle.minimal
)

Input Styles

QuestionStep(
  title: "Outlined Input",
  inputType: InputType.text,
  inputStyle: InputStyle.outline, // or InputStyle.underLined, InputStyle.basic
)

Selection Types

QuestionStep(
  title: "Choose Option",
  inputType: InputType.singleChoice,
  selectionType: SelectionType.tick, // or SelectionType.arrow, SelectionType.toggle, SelectionType.dropdown
  options: [
    Options("option1", "Option 1"),
    Options("option2", "Option 2"),
  ],
)

📋 Form Components

InstructionStep

Display information or instructions to users.

InstructionStep(
  title: "Welcome to Our App",
  text: "Please complete the following steps",
  cancellable: false,
)

QuestionStep

Interactive input fields with validation.

QuestionStep(
  title: "Your Question",
  text: "Additional description",
  inputType: InputType.email,
  isOptional: false,
  id: GenericIdentifier(id: "unique_id"),
)

CompletionStep

Success/completion screen with animations.

CompletionStep(
  title: "Form Completed!",
  text: "Thank you for your submission",
  onFinish: (result) {
    print("Form result: $result");
  },
)

NestedStep

Multi-step forms with sub-forms.

NestedStep(
  title: "Personal Information",
  steps: [
    QuestionStep(/* ... */),
    QuestionStep(/* ... */),
  ],
)

🛡️ Validation

FormStack includes comprehensive validation:

// Built-in validations
ResultFormat.email("Please enter a valid email")
ResultFormat.password("Password must be at least 8 characters")
ResultFormat.notNull("This field is required")

// Custom validation
ResultFormat.custom("Invalid input", (value) => value.length > 5)

// Advanced validations
ResultFormat.phone("Please enter a valid phone number")
ResultFormat.creditCard("Invalid credit card number")
ResultFormat.url("Please enter a valid URL")
ResultFormat.ssn("Invalid Social Security Number")
ResultFormat.zipCode("Invalid ZIP code")
ResultFormat.age("Age must be between 0 and 150")
ResultFormat.percentage("Percentage must be between 0 and 100")

📱 Responsive Design

FormStack automatically adapts to different screen sizes:

QuestionStep(
  title: "Responsive Text",
  inputType: InputType.text,
  display: Display.large, // small, normal, medium, large, extraLarge
)

🔧 Advanced Features

Form Progress Tracking

// Get form completion progress
double progress = FormStack.api().getFormProgress();
print("Form is ${(progress * 100).toInt()}% complete");

// Get detailed statistics
Map<String, dynamic> stats = FormStack.api().getFormStats();
print("Total steps: ${stats['totalSteps']}");
print("Completed: ${stats['completedSteps']}");

Conditional Logic

QuestionStep(
  title: "Choose Type",
  inputType: InputType.singleChoice,
  options: [
    Options("personal", "Personal"),
    Options("business", "Business"),
  ],
  relevantConditions: [
    RelevantCondition(
      id: "show_business_fields",
      expression: "IN business",
    ),
  ],
)

Custom Styling

QuestionStep(
  title: "Custom Styled",
  inputType: InputType.text,
  style: UIStyle(
    backgroundColor: Colors.blue,
    foregroundColor: Colors.white,
    borderRadius: 12.0,
    borderColor: Colors.blue.shade300,
  ),
)

📄 JSON Configuration

Create forms using JSON for easy configuration:

{
  "steps": [
    {
      "type": "InstructionStep",
      "title": "Welcome",
      "text": "Please complete this form",
      "cancellable": false
    },
    {
      "type": "QuestionStep",
      "title": "Your Name",
      "inputType": "name",
      "inputStyle": "outline",
      "componentsStyle": "basic",
      "isOptional": false,
      "id": "name"
    },
    {
      "type": "QuestionStep",
      "title": "Email",
      "inputType": "email",
      "inputStyle": "outline",
      "componentsStyle": "basic",
      "isOptional": false,
      "id": "email"
    },
    {
      "type": "CompletionStep",
      "title": "Thank You!",
      "text": "Your information has been submitted",
      "autoTrigger": true,
      "id": "completion"
    }
  ]
}

🎯 Real-World Examples

User Registration Form

FormStack.api().form(
  steps: [
    InstructionStep(
      title: "Create Account",
      text: "Please provide your information to create an account",
    ),
    QuestionStep(
      title: "Full Name",
      inputType: InputType.name,
      id: GenericIdentifier(id: "full_name"),
    ),
    QuestionStep(
      title: "Email Address",
      inputType: InputType.email,
      id: GenericIdentifier(id: "email"),
    ),
    QuestionStep(
      title: "Password",
      inputType: InputType.password,
      id: GenericIdentifier(id: "password"),
    ),
    QuestionStep(
      title: "Phone Number",
      inputType: InputType.number,
      id: GenericIdentifier(id: "phone"),
    ),
    CompletionStep(
      title: "Account Created!",
      text: "Welcome to our platform",
      onFinish: (result) {
        // Handle registration
        print("User registered: $result");
      },
    ),
  ],
).render();

Survey Form

FormStack.api().form(
  steps: [
    InstructionStep(
      title: "Customer Survey",
      text: "Help us improve our service",
    ),
    QuestionStep(
      title: "How satisfied are you?",
      inputType: InputType.smile,
      id: GenericIdentifier(id: "satisfaction"),
    ),
    QuestionStep(
      title: "What features do you use?",
      inputType: InputType.multipleChoice,
      selectionType: SelectionType.tick,
      options: [
        Options("feature1", "Feature 1"),
        Options("feature2", "Feature 2"),
        Options("feature3", "Feature 3"),
      ],
      id: GenericIdentifier(id: "features"),
    ),
    QuestionStep(
      title: "Additional Comments",
      inputType: InputType.text,
      numberOfLines: 3,
      id: GenericIdentifier(id: "comments"),
    ),
  ],
).render();

🏗️ Architecture

FormStack follows a modular architecture:

lib/
├── src/
│   ├── core/           # Core form logic
│   ├── ui/             # UI components
│   │   ├── views/      # Form views
│   │   └── input/      # Input field widgets
│   ├── result/         # Validation and result handling
│   ├── step/           # Step definitions
│   └── utils/          # Utility functions

🔧 Customization

Custom Input Types

// Create custom input widgets by extending BaseStepView
class CustomInputWidget extends BaseStepView<QuestionStep> {
  // Implementation
}

Custom Validation

// Create custom validation rules
ResultFormat.custom("Custom error", (value) {
  return value.contains("@") && value.length > 5;
})

📊 Performance

FormStack is optimized for performance:

• Memory Efficient: Proper disposal of controllers and resources
• Lazy Loading: Components load only when needed
• Optimized Rebuilds: Minimal widget rebuilds
• Caching: Form state caching for better performance

🧪 Testing

FormStack includes comprehensive testing utilities:

// Test form validation
test('email validation', () {
  expect('test@example.com'.isValidEmail(), true);
  expect('invalid-email'.isValidEmail(), false);
});

// Test form completion
test('form completion', () {
  FormStack.api().form(/* ... */);
  expect(FormStack.api().isFormCompleted(), false);
});

🤝 Contributing

We welcome contributions! Please see our Contributing Guide for details.

Development Setup

git clone https://github.com/your-org/formstack.git
cd formstack
flutter pub get
flutter test

📚 Documentation

• API Reference
• Examples
• Migration Guide
• FAQ

🆘 Support

• 📖 Documentation
• 🐛 Issue Tracker
• 💬 Discussions
• 📧 Email Support

📄 License

FormStack is licensed under the MIT License. See LICENSE for details.

🙏 Acknowledgments

• Flutter team for the amazing framework
• Community contributors
• All the developers who use FormStack

📈 Roadmap

• Form analytics and insights
• Auto-save functionality
• Multi-language support
• Advanced conditional logic
• Form templates
• Export/Import functionality
• Real-time collaboration

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