SwapController

Overview

SwapController is the core base class for your MVC controllers. It replaces the standard Controller class and adds HTMX-aware helper methods.

Note: If you prefer composition or Minimal APIs, you can use the Swap.Htmx.Extensions package instead of inheritance.

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Core Features

1. SwapView()

Intelligent view rendering that adapts to the request type.

• Browser Request: Returns View() (Full page with _Layout).
• HTMX Request: Returns PartialView() (Content only).

public IActionResult Index()
{
    var model = _repo.GetData();
    return SwapView(model); // Handles both scenarios automatically
}

2. SwapResponse()

A fluent builder for constructing complex HTMX responses (multi-target updates, triggers, toasts).

[HttpPost]
public IActionResult Save(Note note)
{
    _repo.Save(note);
    
    return SwapResponse()
        .WithView("_NoteList", _repo.GetAll())      // Update main list
        .AlsoUpdate(SwapElements.Count, "_Count")   // Update counter
        .WithSuccessToast("Saved!")                 // Show notification
        .Build();
}

3. SwapEvent()

Trigger an event chain defined in your configuration or distributed handlers.

// Fire and forget - lets handlers decide what ID to update
return SwapEvent(new NoteCreatedEvent(note.Id))
    .WithSuccessToast("Created")
    .Build();

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Sharp Edges

While convenient, SwapController has some "Sharp Edges" to be aware of.

SwapRedirectToAction vs RedirectToAction

• RedirectToAction: Sends a 302 Found response. The browser makes a new GET request.
• SwapRedirectToAction (Obsolete): Was an attempt to forward internally. Avoid usage.

Best Practice: If you need to redirect after a POST (Post-Redirect-Get), use a standard RedirectToAction. HTMX will respect the 302 and fetch the new page.

If you just want to update the UI without a full reload, use SwapView or SwapResponse.