admin-on-rest-fr05t1k/src/reducer/resource/list/queryReducer.js

A frontend Framework for building admin applications on top of REST services, using ES6, React and Material UI

export const SET_SORT = 'SET_SORT';
export const SORT_ASC = 'ASC';
export const SORT_DESC = 'DESC';

export const SET_PAGE = 'SET_PAGE';

export const SET_FILTER = 'SET_FILTER';

const oppositeOrder = direction => (direction === SORT_DESC ? SORT_ASC : SORT_DESC);

/**
 * This reducer is for the react-router query string, NOT for redux.
 */
export default (previousState, { type, payload }) => {
    switch (type) {
    case SET_SORT:
        if (payload === previousState.sort) {
            return {
                ...previousState,
                order: oppositeOrder(previousState.order),
                page: 1,
            };
        }

        return {
            ...previousState,
            sort: payload,
            order: SORT_ASC,
            page: 1,
        };

    case SET_PAGE:
        return { ...previousState, page: payload };

    case SET_FILTER: {
        return { ...previousState, page: 1, filter: payload };
    }

    default:
        return previousState;
    }
};