reactjs - How can I set state in a child component from a parent? -

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i have slider component nested in form in app. slider adjusts parameters live in redux store.

normally, slider controlled, values set props passed down redux store. when slider moved, onchange dispatch action update store, , slider values change.

however, in case, solution poses problems:

  1. the slider has 100+ steps, dragging 50% across means dozens , dozens of onchange events

  2. since slider isn't connected store, every onchange forces re-render on parent, props changing. eviscerates performance.

so, i've implemented partial solution:

  1. the slider values live in slider's state, dragging re-renders slider onchange events.

  2. an afterchange event--which fires when user releases mouse after dragging slider, dispatches new values store.

however, parent has "reset" button should set slider's values initial state.

so, how can communicate slider component parent it's time reset values?

have parent's reset button whatever needs update store. when store changes, updated value used new props.

you can define reset logic componentwillreceiveprops on slider component

https://facebook.github.io/react/docs/component-specs.html#updating-componentwillreceiveprops


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