lib/Core.ts
import * as Bluebird from "bluebird";
import * as MongoDB from "mongodb";
import * as _ from "lodash";
import * as http from "http";
import * as events from "events";
import {Configuration} from "./Configuration";
import {Plugin} from "./Plugins";
import {Model} from "./Model";
import {Instance} from "./Instance";
import {MiddlewareFactory} from "./Middleware";
import * as ExpressMiddleware from "./middleware/Express";
import {ExpressMiddlewareFactory} from "./middleware/Express";
import {Cache} from "./Cache";
import {NoOpCache} from "./caches/NoOpCache";
import {MemoryCache} from "./caches/MemoryCache";
import {BuildUrl} from "./utils/UrlBuilder";
/**
* The Iridium Core, responsible for managing the connection to the database as well
* as any plugins you are making use of.
*
* Generally you will subclass this to provide your own custom core with the models you
* make use of within your application.
*/
export class Core {
/**
* Creates a new Iridium Core instance connected to the specified MongoDB instance
* @param {Iridium.IridiumConfiguration} config The config object defining the database to connect to
* @constructs Core
*/
constructor(config: Configuration);
/**
* Creates a new Iridium Core instance connected to the specified MongoDB instance
* @param {String} url The URL of the MongoDB instance to connect to
* @param {Iridium.IridiumConfiguration} config The config object made available as settings
* @constructs Core
*/
constructor(uri: string, config?: Configuration);
constructor(uri: string | Configuration, config?: Configuration) {
if (typeof uri === "string") {
this._url = uri;
this._config = config;
} else if (uri) {
this._config = uri;
} else {
throw new Error("Expected either a URI or config object to be supplied when initializing Iridium");
}
}
private mongoConnectAsyc = Bluebird.promisify<MongoDB.Db, string, MongoDB.MongoClientOptions>(MongoDB.MongoClient.connect);
private _plugins: Plugin[] = [];
private _url: string;
private _config: Configuration|undefined;
private _connection: MongoDB.Db|undefined;
private _cache: Cache = new NoOpCache();
private _connectPromise: Bluebird<MongoDB.Db>|undefined;
/**
* Gets the plugins registered with this Iridium Core
* @returns {Iridium.Plugin[]}
*/
get plugins(): Plugin[] {
return this._plugins;
}
/**
* Gets the configuration specified in the construction of this
* Iridium Core.
* @returns {Iridium.Configuration}
*/
get settings(): Configuration|undefined {
return this._config;
}
/**
* Gets the currently active database connection for this Iridium
* Core.
* @returns {MongoDB.Db}
*/
get connection(): MongoDB.Db {
if (!this._connection) throw new Error("Iridium Core not connected to a database.");
return this._connection;
}
/**
* Gets the URL used to connect to MongoDB
* @returns {String}
*/
get url(): string {
if (this._url) return this._url;
if (!this._config) throw new Error("No URL or configuration provided");
return BuildUrl(this._config);
}
/**
* Gets the cache used to store objects retrieved from the database for performance reasons
* @returns {cache}
*/
get cache(): Cache {
return this._cache;
}
set cache(value: Cache) {
this._cache = value;
}
/**
* Registers a new plugin with this Iridium Core
* @param {Iridium.Plugin} plugin The plugin to register with this Iridium Core
* @returns {Iridium.Core}
*/
register(plugin: Plugin): Core {
this.plugins.push(plugin);
return this;
}
/**
* Connects to the database server specified in the provided configuration
* @param {function} [callback] A callback to be triggered once the connection is established.
* @returns {Promise}
*/
connect(callback?: (err: Error, core: Core) => any): Bluebird<Core> {
return Bluebird.resolve().then(() => {
if (this._connection) return this._connection;
if (this._connectPromise) return this._connectPromise;
return this._connectPromise = this.mongoConnectAsyc(this.url, this._config && this._config.options || {});
}).then((db: MongoDB.Db) => {
return this.onConnecting(db);
}).then(db => {
this._connection = db;
this._connectPromise = undefined;
return this.onConnected();
}).then(() => {
return this;
}, (err) => {
if (this._connection) this._connection.close();
this._connection = undefined;
this._connectPromise = undefined;
return Bluebird.reject(err);
}).nodeify(callback);
}
/**
* Closes the active database connection
* @type {Promise}
*/
close(): Bluebird<Core> {
return Bluebird.resolve().then(() => {
if (!this._connection) return this;
let conn: MongoDB.Db = this._connection;
this._connection = undefined;
conn.close();
return this;
});
}
/**
* Provides an express middleware which can be used to set the req.db property
* to the current Iridium instance.
* @returns {Iridium.ExpressMiddleware}
*/
express(): ExpressMiddleware.ExpressMiddleware {
return ExpressMiddlewareFactory(this);
}
/**
* A method which is called whenever a new connection is made to the database.
*
* @param {MongoDB.Db} connection The underlying MongoDB connection which was created, you can modify or replace this if you wish.
* @returns A promise for the connection, allowing you to perform any asynchronous initialization required by your application.
*
* In subclassed Iridium Cores this method can be overridden to manipulate the properties
* of the underlying MongoDB connection object, such as authenticating. Until this method
* resolves a connection object, Iridium will be unable to execute any queries. If you wish
* to run Iridium queries then look at the onConnected method.
*/
protected onConnecting(connection: MongoDB.Db): PromiseLike<MongoDB.Db> {
return Bluebird.resolve(connection);
}
/**
* A method which is called once a database connection has been established and accepted by Iridium
*
* In subclassed Iridium cores this method can be overridden to perform tasks whenever a
* connection to the database has been established - such as setting up indexes for your
* collections or seeding the database.
*/
protected onConnected(): PromiseLike<void> {
return Bluebird.resolve();
}
}