# Button

A styled clickable button. Use it for form submissions, navigation actions, or triggering HTMX requests.

---

## Quick example

```csharp
new Button("Save changes", type: "submit")
new Button("Cancel",       variant: "outline")
new Button("Delete",       variant: "destructive")
```

---

## All the options

```csharp
public Button(
    string label,
    string variant = "default",
    string size    = "default",
    string type    = "button",
    string hxAttrs = "")
```

| Parameter | What it does |
|---|---|
| `label` | The button text. Can include raw HTML — useful for icons. |
| `variant` | Visual style. See table below. |
| `size` | How big the button is. See table below. |
| `type` | HTML button type. Use `"submit"` for form submit buttons. Defaults to `"button"`. |
| `hxAttrs` | Extra HTML attributes added verbatim — use this for HTMX, `disabled`, `data-*`, etc. |

**Variants:**

| Variant | Looks like |
|---|---|
| `default` | Filled with the primary colour — use for the main action on a page |
| `destructive` | Red — use for irreversible actions like delete |
| `outline` | Transparent with a border — use for secondary actions |
| `secondary` | Muted fill — use for tertiary actions |
| `ghost` | Invisible until hovered — use for toolbar buttons and icon actions |
| `link` | Looks like a hyperlink with an underline on hover |

**Sizes:**

| Size | Dimensions |
|---|---|
| `sm` | Compact (36px tall) — good for dense UI |
| `default` | Standard (40px tall) |
| `lg` | Large (44px tall) — good for prominent CTAs |
| `icon` | Square (40×40) — for icon-only buttons |

---

## Real-world examples

### Form submit button

```csharp
new Button("Sign in", type: "submit")
```

### Confirm and cancel in a dialog footer

```csharp
var footer = """
    {cancelButton}
    {deleteButton}
    """;

// Pre-render each to HTML string and embed:
string Render(IHtmxComponent c)
{
    var w = new System.Buffers.ArrayBufferWriter<byte>();
    c.Render(new HtmxRenderContext(w));
    return System.Text.Encoding.UTF8.GetString(w.WrittenSpan);
}

new Card(
    content: "<p>Are you sure you want to delete this item?</p>",
    footer:  Render(new Button("Cancel", variant: "outline"))
           + Render(new Button("Delete", variant: "destructive", type: "submit")))
```

### HTMX load more button

```csharp
new Button(
    "Load more",
    variant:  "outline",
    hxAttrs:  """hx-get="/items?page=2" hx-target="#item-list" hx-swap="beforeend"""")
```

### Icon-only ghost button (e.g. a refresh icon in a toolbar)

```csharp
new Button(
    label:   "<svg class='h-4 w-4' ...fill or stroke SVG here/>",
    variant: "ghost",
    size:    "icon")
```

### Disabled state

Button does not have a `disabled` parameter. Pass it through `hxAttrs`:

```csharp
new Button("Processing...", hxAttrs: "disabled aria-disabled='true'")
```

---

## How it works

Button is a `<button>` element — straightforward HTML with Tailwind classes. The `hxAttrs` string is appended verbatim inside the opening `<button>` tag, so any valid HTML attribute works there. The `label` is inserted as raw HTML, which is how inline SVG icons are supported.
```

---

## Tips and tricks

- Use `type: "submit"` only inside `<form>` elements. Outside a form, always use `type: "button"` to prevent accidental page reloads in some browsers.
- `hxAttrs` is written verbatim between the class and the closing `>` of the button tag — you can add any attribute here: `hx-*`, `data-*`, `aria-*`, `onclick`, etc.
- The `ghost` variant has no visible background at rest — use it for toolbar actions or secondary icon buttons.
- The `link` variant looks like an anchor but behaves as a button — useful for inline text actions that trigger JS or HTMX requests rather than navigation.
- To use Button as a DropdownMenu trigger, pass a `Button` instance to `DropdownMenu`'s `trigger` parameter.

---

## Complete page example

**`Templates/SettingsPage.htmx`**
```html
<div class="max-w-lg mx-auto py-10 space-y-6">
  <h1 class="text-2xl font-bold">Settings</h1>
  <div class="flex gap-3">
    $$SaveBtn$$
    $$CancelBtn$$
    $$DangerBtn$$
  </div>
  <div class="border-t pt-4">
    $$LearnMoreLink$$
  </div>
</div>
```

**`Templates/SettingsPage.htmx.cs`**
```csharp
namespace Htmx.ApiDemo.Templates;

public sealed class SettingsPage : SettingsPageBase
{
    private readonly IHtmxComponent _save;
    private readonly IHtmxComponent _cancel;
    private readonly IHtmxComponent _danger;
    private readonly IHtmxComponent _learn;

    public SettingsPage()
    {
        _save   = new Components.Button("Save changes", type: "submit");
        _cancel = new Components.Button("Cancel",       variant: "outline");
        _danger = new Components.Button("Delete account", variant: "destructive",
                      hxAttrs: "data-dialog-open=\"confirm-delete\"");
        _learn  = new Components.Button("Learn more about settings", variant: "link");
    }

    protected override void RenderSaveBtn(HtmxRenderContext ctx)       => _save.Render(ctx.Next());
    protected override void RenderCancelBtn(HtmxRenderContext ctx)     => _cancel.Render(ctx.Next());
    protected override void RenderDangerBtn(HtmxRenderContext ctx)     => _danger.Render(ctx.Next());
    protected override void RenderLearnMoreLink(HtmxRenderContext ctx) => _learn.Render(ctx.Next());
}
```

**GET handler**
```csharp
[Handler]
[MapGet("/settings")]
public static partial class GetSettingsHandler
{
    public record Query();

    private static Task<IResult> HandleAsync(
        Query _,
        HttpContext ctx,
        CancellationToken ct)
        => ctx.WriteHtmxPage(new SettingsPage(), title: "Settings");
}
```