nestjs-keyset-paginator/dist/pagination/generate-pagination-query.js

a simple pagination library made for nestjs(mongoose) by hungreebee technologies

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.generatePaginationQuery = void 0;
/**
 * @param  {} query
 * @param  {} sort?
 * @param  {} nextKey?
 */
const generatePaginationQuery = (query, sort, nextKey) => {
    // console.log('generatePaginationQuery');
    const sortField = sort == null ? null : sort[0];
    /**
     * @param  {} items - array of items
     */
    function nextKeyFn(items) {
        if (items.length === 0) {
            return null;
        }
        const item = items[items.length - 1];
        if (sortField == null) {
            return { _id: item._id };
        }
        return { _id: item._id, [sortField]: item[sortField] };
    }
    let paginatedQuery = query;
    if (nextKey == null) {
        // console.log('query:\n', paginatedQuery);
        return { paginatedQuery, nextKeyFn };
    }
    if (sort == null) {
        paginatedQuery._id = { $gt: nextKey._id };
        // console.log('sort null return')
        return { paginatedQuery, nextKeyFn };
    }
    const sortOperator = sort[1] === 1 ? '$gt' : '$lt';
    const paginationQuery = [
        { [sortField]: { [sortOperator]: nextKey[sortField] } },
        {
            $and: [{ [sortField]: nextKey[sortField] }, { _id: { [sortOperator]: nextKey._id } }]
        }
    ];
    if (paginatedQuery.$or == null) {
        paginatedQuery.$or = paginationQuery;
    }
    else {
        paginatedQuery = { $and: [query, { $or: paginationQuery }] };
    }
    return { paginatedQuery, nextKeyFn };
};
exports.generatePaginationQuery = generatePaginationQuery;