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mongoose-paginate-v2

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A custom pagination library for Mongoose with customizable labels.

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"use strict"; function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); if (enumerableOnly) { symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; }); } keys.push.apply(keys, symbols); } return keys; } function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; if (i % 2) { ownKeys(Object(source), true).forEach(function (key) { _defineProperty(target, key, source[key]); }); } else if (Object.getOwnPropertyDescriptors) { Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)); } else { ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } } return target; } function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; } /** * Pagination process for sub-documents * internally, it would call `query.findOne`, return only one document * * @param {Object} query * @param {Object} options * @param {Function} callback */ function paginateSubDocs(query, options, callback) { /** * Populate sub documents with pagination fields * * @param {Object} query * @param {Object} populate origin populate option * @param {Object} option */ function getSubDocsPopulate(option) { // options properties for sub-documents pagination var populate = option.populate, _option$page = option.page, page = _option$page === void 0 ? 1 : _option$page, _option$limit = option.limit, limit = _option$limit === void 0 ? 10 : _option$limit; if (!populate) { throw new Error('populate is required'); } var offset = (page - 1) * limit; option.offset = offset; var pagination = { skip: offset, limit: limit }; if (typeof populate === 'string') { populate = _objectSpread({ path: populate }, pagination); } else if (typeof populate === 'object' && !Array.isArray(populate)) { populate = Object.assign(populate, pagination); } option.populate = populate; return populate; } function populateResult(result, populate) { return result.populate(populate); } /** * Convert result of sub-docs list to pagination like docs * * @param {Object} result query result * @param {Object} option pagination option */ function constructDocs(paginatedResult, option) { var populate = option.populate, _option$offset = option.offset, offset = _option$offset === void 0 ? 0 : _option$offset, _option$page2 = option.page, page = _option$page2 === void 0 ? 1 : _option$page2, _option$limit2 = option.limit, limit = _option$limit2 === void 0 ? 10 : _option$limit2; var path = populate.path; var count = option.count; var paginatedDocs = paginatedResult[path]; if (!paginatedDocs) { throw new Error(`Parse error! Cannot find key on result with path ${path}`); } page = Math.ceil((offset + 1) / limit); // set default meta var meta = { docs: paginatedDocs, totalDocs: count || 1, limit: limit, page: page, prevPage: null, nextPage: null, hasPrevPage: false, hasNextPage: false }; var totalPages = limit > 0 ? Math.ceil(count / limit) || 1 : null; meta.totalPages = totalPages; meta.pagingCounter = (page - 1) * limit + 1; // Set prev page if (page > 1) { meta.hasPrevPage = true; meta.prevPage = page - 1; } else if (page == 1 && offset !== 0) { meta.hasPrevPage = true; meta.prevPage = 1; } // Set next page if (page < totalPages) { meta.hasNextPage = true; meta.nextPage = page + 1; } if (limit == 0) { meta.limit = 0; meta.totalPages = 1; meta.page = 1; meta.pagingCounter = 1; } Object.defineProperty(paginatedResult, path, { value: meta, writable: false }); } // options properties for main document query var populate = options.populate, _options$read = options.read, read = _options$read === void 0 ? {} : _options$read, _options$select = options.select, select = _options$select === void 0 ? '' : _options$select, _options$pagination = options.pagination, pagination = _options$pagination === void 0 ? true : _options$pagination, pagingOptions = options.pagingOptions, projection = options.projection; var mQuery = this.findOne(query, projection); if (read && read.pref) { /** * Determines the MongoDB nodes from which to read. * @param read.pref one of the listed preference options or aliases * @param read.tags optional tags for this query */ mQuery.read(read.pref, read.tags); } if (select) { mQuery.select(select); } return new Promise(function (resolve, reject) { mQuery.exec().then(function (result) { var newPopulate = []; if (populate) { newPopulate.push(newPopulate); } if (pagination && pagingOptions) { if (Array.isArray(pagingOptions)) { pagingOptions.forEach(function (option) { var populate = getSubDocsPopulate(option); option.count = result[populate.path].length; newPopulate.push(populate); }); } else { var _populate = getSubDocsPopulate(pagingOptions); pagingOptions.count = result[_populate.path].length; newPopulate.push(_populate); } } populateResult(result, newPopulate).then(function (paginatedResult) { // convert paginatedResult to pagination docs if (pagination && pagingOptions) { if (Array.isArray(pagingOptions)) { pagingOptions.forEach(function (option) { constructDocs(paginatedResult, option); }); } else { constructDocs(paginatedResult, pagingOptions); } } callback && callback(null, paginatedResult); resolve(paginatedResult); }); }).catch(function (err) { console.error(err.message); callback && callback(err, null); reject(err); }); }); } module.exports = paginateSubDocs;