Moka.Blazor.Json.Abstractions 0.1.10

Moka.Blazor.Json

A high-performance Blazor JSON viewer and editor component with virtualized rendering, search, theming, and plugin support.

Features

• Virtualized rendering - handles documents up to 100 MB with smooth scrolling
• Search - plain text, regex, case-sensitive with match navigation
• Theming - light, dark, auto (system preference), or fully custom via CSS variables
• Context menu - built-in actions + extensible custom actions with type/property filtering
• Breadcrumb navigation - clickable path segments for easy traversal
• Streaming parsing - incremental parsing for large documents via JsonStream
• Key sorting - sort object keys alphabetically (single level or recursive)
• Node scoping - zoom into any subtree
• Zero external dependencies - built on System.Text.Json
• Multi-target - supports .NET 9, and .NET 10

Installation

dotnet add package Moka.Blazor.Json

Quick Start

1. Register services

// Program.cs
builder.Services.AddMokaJsonViewer();

2. Add the component

@using Moka.Blazor.Json.Components

<MokaJsonViewer Json="@myJson" />

@code {
    private string myJson = """{"name":"Alice","age":30,"tags":["dev","admin"]}""";
}

3. Two-way binding

<MokaJsonViewer @bind-Json="myJson" />

@code {
    private string myJson = """{"name":"Alice"}""";
    // myJson updates automatically when the document is modified
}

Parameters

Configuration

builder.Services.AddMokaJsonViewer(options =>
{
    options.DefaultTheme = MokaJsonTheme.Dark;
    options.DefaultExpandDepth = 3;
    options.MaxDocumentSizeBytes = 200 * 1024 * 1024; // 200 MB
    options.SearchDebounceMs = 300;
    options.StreamingThresholdBytes = 2 * 1024 * 1024; // 2 MB
    options.MaxClipboardSizeBytes = 100 * 1024 * 1024; // 100 MB
});

Programmatic Control

The component implements IMokaJsonViewer for programmatic access:

<MokaJsonViewer @ref="_viewer" Json="@json" />

@code {
    private MokaJsonViewer _viewer = null!;

    private async Task NavigateToUser()
    {
        await _viewer.NavigateToAsync("/users/0/name");
    }

    private async Task Search()
    {
        var matchCount = await _viewer.SearchAsync("error", new JsonSearchOptions
        {
            CaseSensitive = false,
            UseRegex = true,
            SearchKeys = true,
            SearchValues = true
        });
    }
}

Available methods:

• NavigateToAsync(jsonPointer) - Navigate to a JSON Pointer path
• ExpandToDepth(depth) - Expand nodes to depth (-1 for all)
• ExpandAll() / CollapseAll() - Expand or collapse the entire tree
• SearchAsync(query, options) - Search with optional regex/case sensitivity
• NextMatch() / PreviousMatch() - Navigate search results
• ClearSearch() - Clear search state
• GetJson(indented) - Get the current JSON as a string

Custom Context Menu Actions

Add type-aware context menu actions:

private readonly List<MokaJsonContextAction> _actions =
[
    new MokaJsonContextAction
    {
        Id = "open-url",
        Label = "Open URL",
        ShortcutHint = "Enter",
        Order = 500,
        HasSeparatorBefore = true,
        IsVisible = ctx => ctx.ValueKind == JsonValueKind.String
                           && ctx.RawValuePreview.StartsWith("\"http", StringComparison.OrdinalIgnoreCase),
        OnExecute = ctx =>
        {
            var url = ctx.RawValuePreview.Trim('"');
            // Open URL...
            return ValueTask.CompletedTask;
        }
    },
    new MokaJsonContextAction
    {
        Id = "format-currency",
        Label = "Format as Currency",
        Order = 510,
        IsVisible = ctx => ctx.ValueKind == JsonValueKind.Number
                           && ctx.PropertyName is "salary" or "price" or "amount",
        OnExecute = ctx =>
        {
            // Format number as currency...
            return ValueTask.CompletedTask;
        }
    }
];

<MokaJsonViewer Json="@json" ContextMenuActions="_actions" />

Theming

Built-in themes

<MokaJsonViewer Json="@json" Theme="MokaJsonTheme.Dark" />

Custom CSS variables

Override any of these CSS custom properties:

.my-custom-theme {
    /* Syntax highlighting */
    --moka-json-color-key: #0451a5;
    --moka-json-color-string: #a31515;
    --moka-json-color-number: #098658;
    --moka-json-color-boolean: #0000ff;
    --moka-json-color-null: #808080;
    --moka-json-color-bracket: #319331;

    /* UI */
    --moka-json-bg: transparent;
    --moka-json-color-text: #1e1e1e;
    --moka-json-color-border: #e0e0e0;
    --moka-json-color-hover: rgba(0, 0, 0, 0.04);
    --moka-json-color-selected: rgba(0, 120, 212, 0.1);
    --moka-json-toolbar-bg: #f3f3f3;
    --moka-json-context-bg: #ffffff;

    /* Search highlighting */
    --moka-json-color-search-match: rgba(234, 192, 0, 0.4);
    --moka-json-color-search-active: rgba(234, 128, 0, 0.6);

    /* Typography */
    --moka-json-font-family: 'Cascadia Code', 'Fira Code', Consolas, monospace;
    --moka-json-font-size: 13px;
    --moka-json-line-height: 1.6;
}

Use Theme="MokaJsonTheme.Inherit" to apply your own theme class without any built-in overrides.

Keyboard Shortcuts

Event Callbacks

<MokaJsonViewer Json="@json"
                OnNodeSelected="HandleNodeSelected"
                OnError="HandleError" />

@code {
    private void HandleNodeSelected(JsonNodeSelectedEventArgs e)
    {
        Console.WriteLine($"Selected: {e.Path} ({e.ValueKind})");
        Console.WriteLine($"Property: {e.PropertyName}");
        Console.WriteLine($"Preview: {e.RawValuePreview}");
    }

    private void HandleError(JsonErrorEventArgs e)
    {
        Console.WriteLine($"Error at line {e.LineNumber}: {e.Message}");
    }
}

Streaming Large Documents

For documents too large to hold in a string, use JsonStream:

<MokaJsonViewer JsonStream="@_stream" />

@code {
    private Stream? _stream;

    private async Task LoadLargeFile()
    {
        _stream = File.OpenRead("large-data.json");
    }
}

Project Structure

src/
  Moka.Blazor.Json/              # Main component library
  Moka.Blazor.Json.Abstractions/ # Interfaces and models
tests/
  Moka.Blazor.Json.Tests/        # Unit + bUnit component tests
  Moka.Blazor.Json.Benchmarks/   # Performance benchmarks
samples/
  Moka.Blazor.Json.Demo/         # Interactive demo application

License

MIT