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    Function useLayoutObservable

    • Same as [[useObservable]] excepts using useLayoutEffect.

      Accepts a function that returns an Observable. Optionally accepts an array of dependencies which will be turned into Observable and be passed to the init function.

      React functional components are called many times during their lifecycle. Create or transform Observables in init function so that the operations won't be repeatedly performed.

      ⚠ Note: useLayoutObservable will call init once and always return the same Observable. It is not safe to access closure (except other Observables) directly inside init. You should use ref or pass them as dependencies through the second argument.

      ⚠ Note: Due to rules of hooks you can either offer or omit the dependencies array but do not change to one another during Component's life cycle. The length of the dependencies array must also be fixed.

      Type Parameters

      • TOutput

        Output value in Observable

      Parameters

      • init: () => Observable<TOutput>

        A pure function that, when applied to an Observable, returns an Observable.

      Returns Observable<TOutput>

    • Type Parameters

      • TOutput

        Output value within Observable.

      • TInputs extends readonly any[]

        A readonly tuple of all dependencies.

      Parameters

      • init: (inputs$: Observable<[...TInputs[]]>) => Observable<TOutput>

        A pure function that, when applied to an Observable, returns an Observable.

      • inputs: [...TInputs[]]

        An dependency array with fixed length. When one of the dependencies changes the Observable in init will emit an array of all the dependencies.

      Returns Observable<TOutput>

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