react-beautiful-dnd/src/state/dimension-structures.js

Beautiful, accessible drag and drop for lists with React.js

// @flow
import memoizeOne from 'memoize-one';
import type {
  DroppableId,
  DraggableId,
  DroppableDimension,
  DroppableDimensionMap,
  DraggableDimension,
  DraggableDimensionMap,
} from '../types';

export const toDroppableMap = memoizeOne(
  (droppables: DroppableDimension[]): DroppableDimensionMap =>
    droppables.reduce((previous, current) => {
      previous[current.descriptor.id] = current;
      return previous;
    }, {}),
);

export const toDraggableMap = memoizeOne(
  (draggables: DraggableDimension[]): DraggableDimensionMap =>
    draggables.reduce((previous, current) => {
      previous[current.descriptor.id] = current;
      return previous;
    }, {}),
);

export const toDroppableList = memoizeOne(
  (droppables: DroppableDimensionMap): DroppableDimension[] =>
    Object.keys(droppables).map(
      (id: DroppableId): DroppableDimension => droppables[id],
    ),
);

export const toDraggableList = memoizeOne(
  (draggables: DraggableDimensionMap): DraggableDimension[] =>
    Object.keys(draggables).map(
      (id: DraggableId): DraggableDimension => draggables[id],
    ),
);