StructuredJson

StructuredJson

A powerful .NET library for creating, reading, and updating JSON objects using a path-based API. Built with Dictionary<string, object?> as the underlying data structure and System.Text.Json for serialization.

Features

• Path-based API: Use intuitive path syntax to navigate and manipulate JSON structures
• .NET Standard 2.0: Compatible with all modern .NET platforms
• System.Text.Json: Uses the modern, high-performance JSON serializer
• Type Safety: Generic methods with intelligent type conversion for strongly-typed value retrieval
• Comprehensive: Full CRUD operations with path validation and robust error handling
• Smart Type Conversion: Automatic conversion between strings and numbers, plus JsonElement handling
• Array Support: Full array manipulation with automatic null-filling for sparse arrays
• Well Documented: Complete XML documentation and extensive unit tests

Installation

Install via NuGet Package Manager:

dotnet add package StructuredJson

Or via Package Manager Console:

Install-Package StructuredJson

Quick Start

using StructuredJson;

// Create a new instance
var sj = new StructuredJson();

// Set values using path syntax
sj.Set("user:name", "John Doe");
sj.Set("user:age", 30);
sj.Set("user:addresses[0]:city", "Ankara");
sj.Set("user:addresses[0]:country", "Turkey");
sj.Set("user:addresses[1]:city", "Istanbul");

// Get values with automatic type conversion
var name = sj.Get("user:name");                    // "John Doe"
var age = sj.Get<int>("user:age");                 // 30
var city = sj.Get("user:addresses[0]:city");       // "Ankara"

// Convert to JSON
var json = sj.ToJson();
Console.WriteLine(json);

// List all paths
var paths = sj.ListPaths();
foreach (var kvp in paths)
{
    Console.WriteLine($"{kvp.Key}: {kvp.Value}");
}

Path Syntax

The library uses a simple and intuitive path syntax with comprehensive validation:

• Object Properties: Use : to separate object properties

  • "user:name" → user.name
  • "config:database:host" → config.database.host

• Array Elements: Use [index] to access array elements

  • "users[0]" → users[0]
  • "items[2]:name" → items[2].name

• Complex Paths: Combine objects and arrays

  • "user:addresses[0]:city" → user.addresses[0].city
  • "data:items[1]:properties[0]:value" → data.items[1].properties[0].value

Path Validation

The library performs comprehensive path validation and throws ArgumentException for:

• Empty or null paths
• Empty array indices (items[])
• Invalid array indices (non-numeric: items[abc])
• Negative array indices (items[-1])
• Multiple array indices in one segment (items[0][1])
• Invalid path segments

API Reference

Constructors

// Create empty structure
var sj = new StructuredJson();

// Create from JSON string (with validation)
var sj = new StructuredJson(jsonString);

Core Methods

Set(string path, object? value)

Sets a value at the specified path. Creates nested structures and arrays automatically.

sj.Set("user:name", "John");
sj.Set("user:addresses[0]:city", "Ankara");
sj.Set("items[5]", "value"); // Creates sparse array with nulls at indices 0-4

Throws: ArgumentException for invalid paths

Get(string path)

Gets a value from the specified path. Returns null if path doesn't exist.

var value = sj.Get("user:name");

Throws: ArgumentException for invalid paths

Get(string path)

Gets a strongly-typed value with intelligent type conversion.

var age = sj.Get<int>("user:age");
var isActive = sj.Get<bool>("user:isActive");
var name = sj.Get<string>("user:name");

// Smart conversions
sj.Set("stringNumber", "42");
var number = sj.Get<int>("stringNumber");  // Returns 42

sj.Set("numberAsString", 123);
var text = sj.Get<string>("numberAsString"); // Returns "123"

Type Conversion Features:

• String ↔ Number conversions (int, long, double, decimal, float)
• JsonElement handling for complex deserialization
• Fallback to JsonSerializer for complex types
• Returns default(T) for failed conversions

ToJson(JsonSerializerOptions? options = null)

Converts the structure to a JSON string with optional formatting.

var json = sj.ToJson(); // Pretty-printed by default
var compactJson = sj.ToJson(new JsonSerializerOptions { WriteIndented = false });

ListPaths()

Returns all paths and their values as a dictionary. Handles sparse arrays intelligently.

var paths = sj.ListPaths();
// Returns: Dictionary<string, object?>
// Note: Only includes non-null values for array elements (sparse array support)

HasPath(string path)

Checks if a path exists in the structure with safe error handling.

bool exists = sj.HasPath("user:name");
// Returns false for invalid paths instead of throwing

Remove(string path)

Removes a value at the specified path. For arrays, removes the element and shifts indices.

bool removed = sj.Remove("user:age");
bool arrayRemoved = sj.Remove("items[1]"); // Removes and shifts remaining elements

Clear()

Removes all data from the structure.

sj.Clear();

Examples

Working with Complex Structures

var sj = new StructuredJson();

// Create a user with multiple addresses
sj.Set("user:name", "John Doe");
sj.Set("user:age", 30);
sj.Set("user:isActive", true);

// Home address
sj.Set("user:addresses[0]:type", "home");
sj.Set("user:addresses[0]:street", "123 Main St");
sj.Set("user:addresses[0]:city", "Ankara");
sj.Set("user:addresses[0]:country", "Turkey");

// Work address
sj.Set("user:addresses[1]:type", "work");
sj.Set("user:addresses[1]:street", "456 Business Ave");
sj.Set("user:addresses[1]:city", "Istanbul");
sj.Set("user:addresses[1]:country", "Turkey");

// Hobbies array
sj.Set("user:hobbies[0]", "reading");
sj.Set("user:hobbies[1]", "swimming");
sj.Set("user:hobbies[2]", "coding");

// Convert to JSON
var json = sj.ToJson();

Loading from Existing JSON

var existingJson = """
{
    "config": {
        "database": {
            "host": "localhost",
            "port": 5432,
            "name": "mydb"
        },
        "features": ["auth", "logging", "caching"]
    }
}
""";

var sj = new StructuredJson(existingJson);

// Read values with type conversion
var host = sj.Get("config:database:host");           // "localhost"
var port = sj.Get<int>("config:database:port");      // 5432
var firstFeature = sj.Get("config:features[0]");     // "auth"

// Modify values
sj.Set("config:database:host", "production-server");
sj.Set("config:features[3]", "monitoring");

// Get updated JSON
var updatedJson = sj.ToJson();

Advanced Array Manipulation

var sj = new StructuredJson();

// Create sparse array (automatically fills with nulls)
sj.Set("items[5]", "value at index 5");

// items[0] through items[4] will be null
var nullValue = sj.Get("items[0]"); // null
var actualValue = sj.Get("items[5]"); // "value at index 5"

// Add more items
sj.Set("items[0]", "first item");
sj.Set("items[1]", "second item");

// Remove an item (shifts indices)
sj.Remove("items[1]");
// Now items[1] contains what was previously at items[2]

// ListPaths() only shows non-null array elements
var paths = sj.ListPaths();
// Won't include null array elements in the output

Type Conversion Examples

var sj = new StructuredJson();

// String to number conversions
sj.Set("stringInt", "42");
sj.Set("stringDouble", "3.14");
sj.Set("stringDecimal", "99.99");

var intValue = sj.Get<int>("stringInt");         // 42
var doubleValue = sj.Get<double>("stringDouble"); // 3.14
var decimalValue = sj.Get<decimal>("stringDecimal"); // 99.99

// Number to string conversions
sj.Set("numberValue", 123);
var stringValue = sj.Get<string>("numberValue"); // "123"

// Complex type handling via JsonSerializer
sj.Set("complexObject", new { Name = "Test", Value = 42 });
var complexResult = sj.Get<Dictionary<string, object>>("complexObject");

Error Handling

The library provides comprehensive error handling with specific exception types:

try
{
    var sj = new StructuredJson();
    
    // These will throw ArgumentException with descriptive messages
    sj.Set("", "value");           // "Path cannot be null or empty"
    sj.Set(null, "value");         // "Path cannot be null or empty"
    sj.Set("items[]", "value");    // "Empty array index in path"
    sj.Set("items[abc]", "value"); // "Invalid array index 'abc' in path"
    sj.Set("items[-1]", "value");  // "Negative array index '-1' in path"
    sj.Set("items[0][1]", "value"); // "Multiple array indices not supported"
    
    // Invalid JSON in constructor
    var invalid = new StructuredJson("{invalid json}"); // ArgumentException with JsonException inner
}
catch (ArgumentException ex)
{
    Console.WriteLine($"Invalid argument: {ex.Message}");
    if (ex.InnerException is JsonException jsonEx)
    {
        Console.WriteLine($"JSON Error: {jsonEx.Message}");
    }
}

// Safe methods that don't throw
bool exists = sj.HasPath("invalid[path");  // Returns false instead of throwing
bool removed = sj.Remove("invalid[path"); // Returns false instead of throwing

Performance Considerations

• Dictionary-based: Uses Dictionary<string, object?> internally for O(1) key lookups
• List semantics: Array operations maintain proper list behavior with appropriate performance
• System.Text.Json: Leverages high-performance JSON serialization
• Regex optimization: Path parsing uses compiled regex patterns
• Lazy evaluation: Type conversions are performed only when needed
• Memory efficient: Sparse arrays don't allocate unnecessary null elements in ListPaths()

Thread Safety

StructuredJson is not thread-safe. If you need to access the same instance from multiple threads, implement appropriate synchronization mechanisms such as:

private readonly object _lock = new object();
private readonly StructuredJson _sj = new StructuredJson();

public void SafeSet(string path, object value)
{
    lock (_lock)
    {
        _sj.Set(path, value);
    }
}

Best Practices

• Path Validation: Always handle ArgumentException when working with dynamic paths
• Type Safety: Use generic Get<T>() methods for better type safety
• Error Handling: Use HasPath() to check existence before Get() operations
• Performance: Cache ListPaths() results if called frequently
• Memory: Call Clear() when reusing instances with large datasets

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Changelog

Version 1.0.0

• Initial release
• Path-based JSON manipulation API
• Support for .NET Standard 2.0
• Intelligent type conversion system
• Comprehensive path validation
• Sparse array support
• Robust error handling
• Full XML documentation
• Comprehensive unit test coverage