Plugin Components

Plugin components are Blazor components that integrate into the host application's UI.

Component Base Classes

PluginComponentBase

All plugin components should inherit from PluginComponentBase:

public abstract class PluginComponentBase : ComponentBase

Injected Services:

• PluginContext — Access to MessageBus, Services, StateStore

Helper Methods:

// State management
T? GetState<T>(string key = "default");
void SetState<T>(string key, T value);

// Get plugin ID from manifest
string? GetPluginId();

// Asset loading
Task LoadStylesheetAsync(string href, string? integrity = null);
Task LoadScriptAsync(string src, string? integrity = null);

// Storage access (persistent)
IPluginStorage? Storage { get; }

PluginMenu

For menu/toolbar integration:

public abstract class PluginMenu : PluginComponentBase
{
    public abstract string Icon { get; }      // MudBlazor icon
    public abstract string Title { get; }     // Display title
    public virtual int Order => 100;          // Sort order (lower = first)
    public virtual string? Tooltip => null;   // Optional tooltip
    public virtual PluginMenuItem[]? Items => null;  // Menu items
}

Example:

@inherits PluginMenu

<MudStack>
    <MudText>Custom menu content</MudText>
</MudStack>

@code {
    public override string Icon => Icons.Material.Filled.Build;
    public override string Title => "My Tools";
    public override int Order => 50;

    public override PluginMenuItem[]? Items =>
    [
        new()
        {
            Icon = Icons.Material.Filled.Refresh,
            Text = "Refresh",
            OnClick = async ctx => await RefreshAsync()
        }
    ];
}

PluginContextPanel

For side-panel/drawer integration:

public abstract class PluginContextPanel : PluginComponentBase
{
    public abstract string Icon { get; }
    public abstract string Title { get; }
    public virtual int Order => 100;
    public virtual bool DefaultVisible => true;
}

Example:

@inherits PluginContextPanel

<MudPaper Class="pa-4">
    <MudText Typo="Typo.h6">Status Panel</MudText>
    <MudText>Connected: @_isConnected</MudText>
</MudPaper>

@code {
    public override string Icon => Icons.Material.Filled.Info;
    public override string Title => "Status";
    public override bool DefaultVisible => true;

    private bool _isConnected;
}

Menu Items

PluginMenuItem defines clickable menu actions:

public class PluginMenuItem
{
    public required string Icon { get; init; }
    public required string Text { get; init; }
    public required Func<PluginContext, Task> OnClick { get; init; }
    public bool Disabled { get; init; }
}

Usage:

public override PluginMenuItem[]? Items =>
[
    new()
    {
        Icon = Icons.Material.Filled.Save,
        Text = "Save",
        OnClick = async context =>
        {
            var storage = context.StorageFactory?.CreateForPlugin(GetPluginId()!);
            await storage?.SetAsync("data", _myData);
        }
    },
    new()
    {
        Icon = Icons.Material.Filled.Delete,
        Text = "Clear",
        Disabled = !HasData,
        OnClick = async context => await ClearDataAsync()
    }
];

PluginGuard

Wraps plugin components for error handling and lifecycle:

<PluginGuard PluginInfo="@plugin" Metadata="@metadata">
    <DynamicComponent Type="@metadata.ComponentType" />
</PluginGuard>

Behavior:

• Shows placeholder if plugin is deleted
• Shows "disabled" message if plugin is disabled
• Catches and displays rendering errors
• Optional stack trace display via ShowErrorDetails

Message Bus Integration

Publishing Messages

// From PluginComponentBase
await PublishAsync(new MyMessage("data"));

// With configuration
await Context.PublishAsync(message, new PublishConfiguration
{
    FireAndForget = true
});

Consuming Messages

Implement IConsumer<TMessage>:

@inherits PluginContextPanel
@implements IConsumer<DataUpdatedMessage>

@code {
    public Task Consume(DataUpdatedMessage message)
    {
        // Handle message
        _data = message.NewData;
        StateHasChanged();
        return Task.CompletedTask;
    }
}

WARNING

Disabled plugins don't receive messages (filtered by DisabledPluginConsumerFilter).

Accessing Services

// From context
var dialogService = Context.Services.GetRequiredService<IDialogService>();
var httpClient = Context.Services.GetService<HttpClient>();

// Link opening (if available)
Context.LinkOpenService?.OpenUrl("https://example.com");

// File saving (if available)
await Context.FileSaveService?.SaveFileAsync("data.json", jsonBytes);

Best Practices

1. Use base classes — Always extend PluginComponentBase, PluginMenu, or PluginContextPanel
2. Prefer transient state — Use GetState/SetState for UI state
3. Use persistent storage sparingly — Only for data that must survive restarts
4. Handle null services — Not all services are available on all platforms
5. Clean up subscriptions — Unsubscribe from events in Dispose
6. Keep components focused — One responsibility per component