woocommerce/packages/woocommerce-blocks/assets/js/base/components/pagination/utils.js

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2021-12-10 12:03:04 +00:00
/**
* Given the number of pages to display, the current page and the total pages,
* returns the min and max index of the pages to display in the pagination component.
*
* @param {number} pagesToDisplay Maximum number of pages to display in the pagination component.
* @param {number} currentPage Page currently visible.
* @param {number} totalPages Total pages available.
* @return {Object} Object containing the min and max index to display in the pagination component.
*/
export const getIndexes = ( pagesToDisplay, currentPage, totalPages ) => {
if ( totalPages <= 2 ) {
return { minIndex: null, maxIndex: null };
}
const extraPagesToDisplay = pagesToDisplay - 1;
const tentativeMinIndex = Math.max(
Math.floor( currentPage - extraPagesToDisplay / 2 ),
2
);
const maxIndex = Math.min(
Math.ceil(
currentPage +
( extraPagesToDisplay - ( currentPage - tentativeMinIndex ) )
),
totalPages - 1
);
const minIndex = Math.max(
Math.floor(
currentPage - ( extraPagesToDisplay - ( maxIndex - currentPage ) )
),
2
);
return { minIndex, maxIndex };
};