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@syngrisi/syngrisi

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"use strict"; /* eslint-disable no-param-reassign, valid-jsdoc */ const paginate = (schema) => { /** * @typedef {Object} QueryResult * @property {Document[]} results - Results found * @property {number} page - Current page * @property {number} limit - Maximum number of results per page * @property {number} totalPages - Total number of pages * @property {number} totalResults - Total number of documents */ /** * Query for documents with pagination * @param {Object} [filter] - Mongo filter * @param {Object} [options] - Query options * @param {string} [options.sortBy] - Sorting criteria using the format: sortField:(desc|asc). * Multiple sorting criteria should be separated by commas (,) * @param {string} [options.populate] - Populate data fields. Hierarchy of fields should be separated by (.). * Multiple populating criteria should be separated by commas (,) * @param {number} [options.limit] - Maximum number of results per page (default = 10) * @param {number} [options.page] - Current page (default = 1) * @returns {Promise<QueryResult>} */ // eslint-disable-next-line func-names schema.statics.paginate = async function (filter, options) { let sort = ''; if (options.sortBy) { const sortingCriteria = []; options.sortBy.split(',') .forEach((sortOption) => { const [key, order] = sortOption.split(':'); sortingCriteria.push((order === 'desc' ? '-' : '') + key); }); sort = sortingCriteria.join(' '); } else { sort = { _id: -1 }; } const limit = options.limit && parseInt(options.limit, 10) >= 0 ? parseInt(options.limit, 10) : 10; const page = options.page && parseInt(options.page, 10) > 0 ? parseInt(options.page, 10) : 1; const skip = (page - 1) * limit; const countPromise = this.countDocuments(filter) .exec(); let docsPromise = this.find(filter) .sort(sort) .skip(skip) .limit(limit); if (options.populate) { options.populate.split(',') .forEach((populateOption) => { docsPromise = docsPromise.populate(populateOption .split('.') .reverse() .reduce((a, b) => ({ path: b, populate: a }))); }); } docsPromise = docsPromise.exec(); return Promise.all([countPromise, docsPromise]) .then((values) => { const [totalResults, results] = values; const totalPages = Math.ceil(totalResults / limit); const result = { results, page, limit, totalPages, totalResults, // microseconds timestamp: Number(Date.now() + String(process.hrtime()[1]) .slice(3, 6)), }; return Promise.resolve(result); }); }; }; module.exports = paginate;