Source Generators

TailwindVariants.NET leverages C# Source Generators to provide compile-time helpers for slots and variants. This ensures safer, more efficient, and strongly-typed access to component styling.

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What are Source Generators?

Source Generators are a Roslyn compiler feature that can:

• Analyze your code at compile-time
• Generate additional C# code automatically
• Integrate seamlessly with your project without runtime overhead

In TailwindVariants.NET, they automatically generate:

• Strongly-typed slot accessors
• Helper classes and enums for variants
• Extension methods for getting classes

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Why Use Source Generators?

Without Source Generators, developers would have to rely on raw strings/expression for:

var baseClass = _slots.Map["Base"];
var iconClass =  _slots.Map[s => s.Icon];

This is:

• ❌ Error-prone
• ❌ Not refactor-friendly
• ❌ Hard to maintain

With Source Generators, you can do:

var baseClass = _slots.GetBase();
var iconClass = _slots.GetIcon();

• ✅ Compile-time safety
• ✅ Strongly-typed access
• ✅ Auto-completion in IDE

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How It Works

1. Scans your component types implementing ISlots.

2. Collects public properties that represent slots.

3. Generates helper classes:

   • <ComponentName>SlotsNames — array of slot names
   • <ComponentName>SlotsExtensions — extension methods for slots
   • <ComponentName>SlotsTypes — enum for variants

4. Integrates with TvDescriptor and SlotCollection automatically.

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Example

Suppose you have a Button component:

public sealed partial class Slots : ISlots
{
    public string? Base { get; set; }
    public string? Icon { get; set; }
}

The Source Generator produces:

public static class ButtonSlotsNames
{
    public static IReadOnlyList<string> AllNames => new[] { "Base", "Icon" };
    public static string NameOf(ButtonSlotsTypes key) => AllNames[(int)key];
}

public static class ButtonSlotsExtensions
{
    public static string? Get(this ButtonSlots slots, ButtonSlotsTypes key) 
        => slots.Map[ButtonSlotsNames.NameOf(key)];

    public static string? GetBase(this ButtonSlots slots) 
        => slots.Get(ButtonSlotsTypes.Base);

    public static string? GetIcon(this ButtonSlots slots) 
        => slots.Get(ButtonSlotsTypes.Icon);
}

This allows:

var baseClass = buttonSlots.GetBase(); // type-safe access
var iconClass = buttonSlots.GetIcon();

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Benefits

• No runtime string errors
• Refactor-safe code
• Better IDE support
• Performance optimized — all logic happens at compile-time

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Best Practices

• Always declare your slots as public properties in ISlots classes.
• Keep your components partial so the generator can augment them.
• Use the generated extension methods instead of manually accessing SlotCollection.

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TailwindVariants.NET Source Generators make your Blazor components safer, easier to maintain, and fully integrated with your variant system.