Parameter Field — Cinder component documentation

Overview

Displays an inherited base parameter and an optional local override. Overrides can be reset to the base value and may carry Unsaved or Experimental badges.

Use the default output for a read-only summary, or provide a child snippet to render a NumberInput, Slider, or another numeric editor. The snippet receives the effective value, whether it is overridden, and a setOverride callback.

Usage

<script lang="ts">
  import { ParameterField } from '@lostgradient/cinder';
</script>

<ParameterField id="timeout" label="Timeout" base={30} unit="seconds" />

base is the effective value until override is supplied. The reset action clears the override and calls onOverrideChange(undefined); it never changes base. Use unsaved and experimental to annotate the value's status, not to change persistence or validation.

For a custom editor, the child snippet receives value, overridden, labelledBy, and setOverride. Apply labelledBy to the nested numeric control so the visible parameter label remains its accessible name. The host owns saving and error recovery: keep the override in place while a save fails and report the failure beside the control.

Live preview

30 seconds

When to use

Use when

Editing a numeric setting that inherits a default but can be overridden locally.

Avoid when

Collecting an independent numeric value with no inheritance semantics — use number-input or slider.

Examples

Parameter override

Show an inherited value with a local override.

Props

Props for parameter-field
Name	Type	Default	Description
`id` required	`text`		Stable id used for label and output association.
`label` required	`text`		Visible parameter label.
`base` required	`number`		Inherited or default numeric value.
`override` bindable	`number`		Optional local numeric override. Bindable.
`unit`	`text`		Optional unit appended to the value and reset tooltip.
`onOverrideChange`	`(value: number \| undefined) => void`		Called when the component's own `setOverride` (exposed to `children` as `ParameterFieldEditorState.setOverride`) accepts a value, or its built-in reset action runs—not only when either actually changes the override: calling `setOverride` with the value `override` already holds still notifies. `setOverride` rejecting a `NaN`/infinite value is the one case where nothing happens: no override change, no call here—see that function. Not called when a parent changes the bindable `override` prop programmatically—that update is not distinguishable here from the component's own writes.
`unsaved`	`boolean`	`false`	Marks the current override as not yet persisted. Defaults to `false`.
`experimental`	`boolean`	`false`	Marks the parameter as experimental. Defaults to `false`.
`children`	`snippet`		Optional custom numeric editor. Receives the effective value and override setter.