Changing component behavior

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Changing component behavior

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We have two primary recommendations for customizing Component behavior:

Override state and action props before they are passed to your Component, using the mapContextToProps param. This will override the default mapContextToProps for the component.
Override props before they are passed to your Component’s view.

Override mapContextToProps

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Every Component supports a mapContextToProps prop, which allows you to modify state and actions before they are received by the Component.

This MUST be an immutable function. If you directly update the props or context, you will have major issues in your application.

A practical example might be putting a custom sort on your facet data.

This example orders a list of states by name:

<Facet
  mapContextToProps={(context) => {
    if (!context.facets.states) return context;
    return {
      ...context,
      facets: {
        ...(context.facets || {}),
        states: context.facets.states.map((s) => ({
          ...s,
          data: s.data.sort((a, b) => {
            if (a.value > b.value) return 1;
            if (a.value < b.value) return -1;
            return 0;
          })
        }))
      }
    };
  }}
  field="states"
  label="States"
  show={10}
/>

Overriding view props

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An example of this is modifying the onChange handler of the Paging Component view. Hypothetically, you may need to know every time a user pages past page 1, indicating that they are not finding what they need on the first page of search results.

import { Paging } from "@elastic/react-search-ui";
import { Paging as PagingView } from "@elastic/react-search-ui-views";

function reportChange(value) {
  // Some logic to report the change
}

<Paging
  view={(props) =>
    PagingView({
      ...props,
      onChange: (value) => {
        reportChange(value);
        return props.onChange(value);
      }
    })
  }
/>;

In this example, we did the following:

Looked up what the default view is for our Component in the components guide.
Imported that view as PagingView.
Passed an explicit view to our Paging Component, overriding the onChange prop with our own implementation, and ultimately rendering PagingView with the updated props.

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