loopback-datasource-juggler/lib/connectors/transient.js

151 lines
4.4 KiB
JavaScript

// Copyright IBM Corp. 2014,2016. All Rights Reserved.
// Node module: loopback-datasource-juggler
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT
var util = require('util');
var Connector = require('loopback-connector').Connector;
var utils = require('../utils');
var crypto = require('crypto');
/**
* Initialize the Transient connector against the given data source
*
* @param {DataSource} dataSource The loopback-datasource-juggler dataSource
* @param {Function} [callback] The callback function
*/
exports.initialize = function initializeDataSource(dataSource, callback) {
dataSource.connector = new Transient(null, dataSource.settings);
dataSource.connector.connect(callback);
};
exports.Transient = Transient;
function Transient(m, settings) {
settings = settings || {};
if (typeof settings.generateId === 'function') {
this.generateId = settings.generateId.bind(this);
}
this.defaultIdType = settings.defaultIdType || String;
if (m instanceof Transient) {
this.isTransaction = true;
this.constructor.super_.call(this, 'transient', settings);
this._models = m._models;
} else {
this.isTransaction = false;
this.constructor.super_.call(this, 'transient', settings);
}
}
util.inherits(Transient, Connector);
Transient.prototype.getDefaultIdType = function() {
return this.defaultIdType;
};
Transient.prototype.getTypes = function() {
return ['db', 'nosql', 'transient'];
};
Transient.prototype.connect = function (callback) {
if (this.isTransaction) {
this.onTransactionExec = callback;
} else {
process.nextTick(callback);
}
};
Transient.prototype.generateId = function(model, data, idName) {
var idType;
var props = this._models[model].properties;
if (idName) idType = props[idName] && props[idName].type;
idType = idType || this.getDefaultIdType();
if (idType === Number) {
return Math.floor(Math.random() * 10000); // max. 4 digits
} else {
return crypto.randomBytes(Math.ceil(24/2))
.toString('hex') // convert to hexadecimal format
.slice(0, 24); // return required number of characters
}
};
Transient.prototype.exists = function exists(model, id, callback) {
process.nextTick(function () { callback(null, false); }.bind(this));
};
Transient.prototype.find = function find(model, id, callback) {
process.nextTick(function () { callback(null, null); }.bind(this));
};
Transient.prototype.all = function all(model, filter, callback) {
process.nextTick(function () { callback(null, []); });
};
Transient.prototype.count = function count(model, callback, where) {
process.nextTick(function () { callback(null, 0); });
};
Transient.prototype.create = function create(model, data, callback) {
var props = this._models[model].properties;
var idName = this.idName(model);
if (idName && props[idName]) {
var id = this.getIdValue(model, data) || this.generateId(model, data, idName);
id = (props[idName] && props[idName].type && props[idName].type(id)) || id;
this.setIdValue(model, data, id);
}
this.flush('create', id, callback);
};
Transient.prototype.save = function save(model, data, callback) {
this.flush('save', data, callback);
};
Transient.prototype.update =
Transient.prototype.updateAll = function updateAll(model, where, data, cb) {
var count = 0;
this.flush('update', {count: count}, cb);
};
Transient.prototype.updateAttributes = function updateAttributes(model, id, data, cb) {
if (!id) {
var err = new Error('You must provide an id when updating attributes!');
if (cb) {
return cb(err);
} else {
throw err;
}
}
this.setIdValue(model, data, id);
this.save(model, data, cb);
};
Transient.prototype.destroy = function destroy(model, id, callback) {
this.flush('destroy', null, callback);
};
Transient.prototype.destroyAll = function destroyAll(model, where, callback) {
if (!callback && 'function' === typeof where) {
callback = where;
where = undefined;
}
this.flush('destroyAll', null, callback);
};
/*!
* Flush the cache - noop.
* @param {Function} callback
*/
Transient.prototype.flush = function (action, result, callback) {
process.nextTick(function () { callback && callback(null, result); });
};
Transient.prototype.transaction = function () {
return new Transient(this);
};
Transient.prototype.exec = function (callback) {
this.onTransactionExec();
setTimeout(callback, 50);
};