# Reflect.5. Choosing a view — Mercury LMS

> Contract: `@fiberfx/reflect` 4.1.1; Hypergraph and Hyperscript 4.1.1.

## Contract

String form: variant({source, cases, default?}); boolean form: variant({if, then, else?}). Both accept bind/mapProps/hooks. Missing case or false-without-else renders fallback or null. Only own case names resolve; constructor is not inherited as a view.

## Lifetime

The reflected wrapper owns variant hooks. Changing the selected case does not rerun those hooks, although the selected child may be replaced. Case-specific work belongs to the case component's lifetime.

## Exercise and boundary

[Variant lab](/examples/reflect-lab/index.html?part=variants&lang=en): ready → empty → error → constructor fallback; reset. Unknown fallback is supported selection behavior, not a runtime validation exception or proof of an actual request/retry.

## Source

variant.ts:10-61; variant.test.ts:52-76; collections.test.ts:77-80. npm 4.1.1.

## Navigation

- [HTML](/reflect/variants)
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