95 lines
2.4 KiB
JavaScript
95 lines
2.4 KiB
JavaScript
// Copyright IBM Corp. 2016,2019. All Rights Reserved.
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// Node module: loopback-connector
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// This file is licensed under the MIT License.
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// License text available at https://opensource.org/licenses/MIT
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'use strict';
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const createPromiseCallback = require('./utils').createPromiseCallback;
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module.exports = JSONStringPacker;
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const ISO_DATE_REGEXP = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*))(?:Z|(\+|-)([\d|:]*))?$/;
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/**
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* Create a new Packer instance that can be used to convert between JavaScript
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* objects and a JsonString representation in a String.
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*
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* @param {String} encoding Buffer encoding refer to https://nodejs.org/api/buffer.html#buffer_buffers_and_character_encodings
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*/
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function JSONStringPacker(encoding) {
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this.encoding = encoding || 'base64';
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}
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/**
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* Encode the provided value to a `JsonString`.
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*
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* @param {*} value Any value (string, number, object)
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* @callback {Function} cb The callback to receive the parsed result.
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* @param {Error} err
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* @param {Buffer} data The encoded value
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* @promise
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*/
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JSONStringPacker.prototype.encode = function(value, cb) {
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const encoding = this.encoding;
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cb = cb || createPromiseCallback();
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try {
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const data = JSON.stringify(value, function(key, value) {
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if (Buffer.isBuffer(this[key])) {
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return {
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type: 'Buffer',
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data: this[key].toString(encoding),
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};
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} else {
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return value;
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}
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});
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setImmediate(function() {
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cb(null, data);
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});
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} catch (err) {
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setImmediate(function() {
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cb(err);
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});
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}
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return cb.promise;
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};
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/**
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* Decode the JsonString value back to a JavaScript value.
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* @param {String} jsonString The JsonString input.
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* @callback {Function} cb The callback to receive the composed value.
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* @param {Error} err
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* @param {*} value Decoded value.
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* @promise
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*/
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JSONStringPacker.prototype.decode = function(jsonString, cb) {
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const encoding = this.encoding;
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cb = cb || createPromiseCallback();
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try {
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const value = JSON.parse(jsonString, function(k, v) {
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if (v && v.type && v.type === 'Buffer') {
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return new Buffer(v.data, encoding);
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}
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if (ISO_DATE_REGEXP.exec(v)) {
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return new Date(v);
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}
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return v;
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});
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setImmediate(function() {
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cb(null, value);
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});
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} catch (err) {
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setImmediate(function() {
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cb(err);
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});
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}
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return cb.promise;
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};
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