Event Hook Attributes

Event hook attributes enable and configure backend handlers for DOM events. Each attribute is a struct rendered before or spread onto an element to bind a typed On handler and optional client-side behavior.

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Common Options

Most event hook attributes share these fields:

• StopPropagation · stop event bubbling.
• PreventDefault · prevent the browser default.
• ExactTarget · fire only on the element itself.
• Scope []Scope · control scheduling (blocking, debounce, etc.).
• Indicator []Indicator · UI indication while running.
• Before []Action · actions before request.
• OnError []Action · actions on error.
• On func(context.Context, REvent[T]) bool · backend handler, return true to complete and remove the hook. Type T depends on the event.

Render inline:

@doors.AClick{
  PreventDefault: true,
  On: func(ctx context.Context, ev doors.REvent[doors.PointerEvent]) bool {
    /* logic */
    return false
  },
}
<button>Click</button>

Or spread:

{{ click := doors.AClick{ On: func(ctx context.Context, ev doors.REvent[doors.PointerEvent]) bool { return true } } }}
<button { doors.A(ctx, click)... }>Click</button>

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Available Attributes

Pointer events

• AClick
• APointerDown, APointerUp, APointerMove
• APointerOver, APointerOut, APointerEnter, APointerLeave
• APointerCancel
• AGotPointerCapture, ALostPointerCapture

All use REvent[PointerEvent]. Support propagation and default control.

Focus events

• AFocus, ABlur
  Use REvent[FocusEvent]. Basic capture.
• AFocusIn, AFocusOut
  Support StopPropagation and ExactTarget.

Keyboard events

• AKeyDown, AKeyUp
  Use REvent[KeyboardEvent]. Support Filter []string on event.key, plus propagation/default options.

Input and change

• AInput · REvent[InputEvent] with optional ExcludeValue.
• AChange · REvent[ChangeEvent] for committed value changes.

Forms

• ASubmit[T] · multipart parsing and decoding into T (via go-playground/form v4). Optional MaxMemory. Handler gets RForm[T].
• ARawSubmit · raw multipart access for streaming/uploads. Handler gets RRawForm.

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Concurrency

Within a single hook, backend On calls are serialized. Multiple events on the same handler queue on the backend. Reusing a pre-initialized attribute across elements joins their queue.

@doors.ASubmit[Data]{
  On: func(ctx context.Context, r doors.RForm[Data]) bool {
    /* safe, next call runs after this returns */
    return false
  },
}
<form>...</form>

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Scopes

Use scopes for precise scheduling, such as debounce and blocking.

@doors.AInput{
  Scope: doors.ScopeOnlyDebounce(300 * time.Millisecond, time.Second),
  On: func(ctx context.Context, r doors.REvent[doors.InputEvent]) bool { return false },
}

See Scopes for details.

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Indicators

Apply pending indication with the Indicator API.

@doors.ASubmit[loginData]{
  Indicator: doors.IndicatorOnlyAttrQuery("#login-submit", "aria-busy", "true"),
  Scope:     doors.ScopeOnlyBlocking(),
  On: func(ctx context.Context, r doors.RForm[loginData]) bool { return true },
}

See Indication for details.

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Errors

OnError runs when a hook processing error occurs. It supports UI indication, navigation, and custom JS actions. See Actions and JavaScript for error object details.