loopback-connector-remote/lib/remote-connector.js

127 lines
3.4 KiB
JavaScript

// Copyright IBM Corp. 2014,2016. All Rights Reserved.
// Node module: loopback-connector-remote
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT
'use strict';
/**
* Dependencies.
*/
var assert = require('assert');
var remoting = require('strong-remoting');
var utils = require('loopback-datasource-juggler/lib/utils');
var jutil = require('loopback-datasource-juggler/lib/jutil');
var RelationMixin = require('./relations');
var InclusionMixin = require('loopback-datasource-juggler/lib/include');
/**
* Export the RemoteConnector class.
*/
module.exports = RemoteConnector;
/**
* Create an instance of the connector with the given `settings`.
*/
function RemoteConnector(settings) {
assert(typeof settings ===
'object',
'cannot initiaze RemoteConnector without a settings object');
this.client = settings.client;
this.adapter = settings.adapter || 'rest';
this.protocol = settings.protocol || 'http';
this.root = settings.root || '';
this.host = settings.host || 'localhost';
this.port = settings.port || 3000;
this.remotes = remoting.create();
this.name = 'remote-connector';
if (settings.url) {
this.url = settings.url;
} else {
this.url = this.protocol + '://' + this.host + ':' + this.port + this.root;
}
// handle mixins in the define() method
var DAO = this.DataAccessObject = function() {
};
}
RemoteConnector.prototype.connect = function() {
this.remotes.connect(this.url, this.adapter);
};
RemoteConnector.initialize = function(dataSource, callback) {
var connector = dataSource.connector =
new RemoteConnector(dataSource.settings);
connector.connect();
process.nextTick(callback);
};
RemoteConnector.prototype.define = function(definition) {
var Model = definition.model;
var remotes = this.remotes;
assert(Model.sharedClass,
'cannot attach ' +
Model.modelName +
' to a remote connector without a Model.sharedClass');
jutil.mixin(Model, RelationMixin);
jutil.mixin(Model, InclusionMixin);
remotes.addClass(Model.sharedClass);
this.resolve(Model);
};
RemoteConnector.prototype.resolve = function(Model) {
var remotes = this.remotes;
Model.sharedClass.methods().forEach(function(remoteMethod) {
if (remoteMethod.name !== 'Change' && remoteMethod.name !== 'Checkpoint') {
createProxyMethod(Model, remotes, remoteMethod);
}
});
// setup a remoting type converter for this model
remotes.defineType(Model.modelName, function(val) {
return val ? new Model(val) : val;
});
};
function createProxyMethod(Model, remotes, remoteMethod) {
var scope = remoteMethod.isStatic ? Model : Model.prototype;
var original = scope[remoteMethod.name];
function remoteMethodProxy() {
var args = Array.prototype.slice.call(arguments);
var lastArgIsFunc = typeof args[args.length - 1] === 'function';
var callback;
if (lastArgIsFunc) {
callback = args.pop();
} else {
callback = utils.createPromiseCallback();
}
if (remoteMethod.isStatic) {
remotes.invoke(remoteMethod.stringName, args, callback);
} else {
var ctorArgs = [this.id];
remotes.invoke(remoteMethod.stringName, ctorArgs, args, callback);
}
return callback.promise;
}
scope[remoteMethod.name] = remoteMethodProxy;
remoteMethod.aliases.forEach(function(alias) {
scope[alias] = remoteMethodProxy;
});
}
function noop() {
}