CSX Compiler

UltimateUI.Components.SourceGen reads *.uui.csx AdditionalFiles and turns CSX return expressions inside C# methods into ordinary element construction code.

<ProjectReference Include="..\..\src\UltimateUI.Components.SourceGen\UltimateUI.Components.SourceGen.csproj"
                  OutputItemType="Analyzer"
                  ReferenceOutputAssembly="false" />
<AdditionalFiles Include="WelcomeCard.uui.csx" />

using System;
using UltimateUI;
using UltimateUI.Components;
using UltimateUI.Events;

namespace MyApp.Views;

public static partial class WelcomeCard
{
    public static Element Render(ComponentContext context, string title, int count, EventHandler<ClickEventArgs>? onClick)
    {
        var caption = $"Clicked {count}";
        return (
            <div className="card">
                <h1>{title}</h1>
                <button onClick={onClick}>{caption}</button>
            </div>
        );
    }
}

Generated usage:

var element = WelcomeCard.Render(context, "CSX", 3, OnClick);

Supported today: C# using directives, file-scoped namespaces, partial classes, C# method signatures whose first parameter is ComponentContext context, ordinary C# statements before the CSX return, one XML-like root element, text interpolation, attribute interpolation, children, onClick={handler} / onInput={handler} event bindings, and {rows} insertion from an IEnumerable<Element>. All attribute names must be camelCase and cannot contain -; use ariaLabel, htmlFor, and onClick, not aria-label, html-for, or on-click. PascalCase tags are function component calls, so <CounterView /> emits CounterView.Render(context).

The old top-level component / function declarations, class=, hyphenated attributes such as on-click="handler" and aria-label="...", and <slot name="rows" /> syntax have been removed.