nocobase/docs/en-US/api/server/application.md

Application

Overview

Web Service

NocoBase Application is a web framework implemented based on Koa, compatible with Koa API.

// index.js
const { Application } = require('@nocobase/server');

// Create App instance and configure the database
const app = new Application({
    database: {
        dialect: 'sqlite',
        storage: ':memory:',
    }
});

// Register middleware, response to requests
app.use(async ctx => {
  ctx.body = 'Hello World';
});

// Run in the CLI mode
app.runAsCLI();

After running node index.js start in CLI to start service, use curl to request service.

$> curl localhost:3000
Hello World

CLI Tool

NocoBase Application has a built-in cli commander, which can be run as CLI tool.

// cmd.js
const {Application} = require('@nocobase/server');
const app = new Application({
  database: {
    dialect: 'sqlite',
    storage: ':memory:',
  }
});

app.cli.command('hello').action(async () => {
  console.log("hello world")
});

app.runAsCLI()

Run in CLI:

$> node cmd.js hello
hello world

Inject Plugin

NocoBase Application is designed as a highly extensible framework, plugins can be written and injected to the applicationto to extend its functionality. For example, the above-mentioned web service can be replaced with a plugin.

const { Application, Plugin } = require('@nocobase/server');

// Write plugin by inheriting the Plugin class
class HelloWordPlugin extends Plugin {
  load() {
    this.app.use(async (ctx, next) => {
      ctx.body = "Hello World";
    })
  }
}

const app = new Application({
  database: {
    dialect: 'sqlite',
    storage: ':memory:',
  }
});

// Inject plugin
app.plugin(HelloWordPlugin, { name: 'hello-world-plugin'} );

app.runAsCLI()

More Examples

Please refer to the detailed guides of plugin development. Read more examples of the Application class.

Life Cycle

Application has three life cycle stages depends on the running mode.

Install

Use the install command in cli to invoke the installation. Generally, if needs to write new tables or data to the database before using the plugin, you have to do it during installation. Installation is also required when using NocoBase for the first time.

• Call the load method to load registered plugins.
• Trigger the beforeInstall event.
• Call the db.sync method to synchronize database.
• Call the pm.install method to execute the install methods of registered plugins.
• Write the version of nocobase.
• Trigger the afterInstall event.
• Call the stop method to end installation.

Start

Use the start command in cli to start NocoBase Web service.

• Call the load method to load registered plugins.
• Call the start medthod:
  • Trigger the beforeStart event
  • Start port listening
  • Trigger the afterStart event

Upgrade

Use the upgrade command in cli to upgrade NocoBase Web service when needed.

• Call the load method to load registered plugins.
• Trigger the beforeUpgrade event.
• Call the db.migrator.up method to migrate database.
• Call the db.sync method to synchronize database.
• Call the version.update method to update the version of nocobase.
• Trigger the afterUpgrade event.
• Call the stop medthod to end upgrade.

Constructor

constructor()

Create an application instance.

Signature

• constructor(options: ApplicationOptions)

Parameters

Name	Type	Default	Description
options.database	IDatabaseOptions or Database	{}	Database configuration
options.resourcer	ResourcerOptions	{}	Resource route configuration
options.logger	AppLoggerOptions	{}	Log
options.cors	CorsOptions	{}	Cross-domain configuration, refer to @koa/cors
options.dataWrapping	boolean	true	Whether or not to wrap the response data, true will wrap the usual ctx.body into a { data, meta } structure
options.registerActions	boolean	true	Whether or not to register the default actions
options.i18n	I18nOptions	{}	Internationalization configuration, refer to i18next
options.plugins	PluginConfiguration[]	[]	Configuration of the plugins enabled by default

Type

interface ApplicationOptions {

}

Instance Members

cli

CLI tool instance, refer to the npm package Commander。

db

Database instance, refer to Database for the related API.

resourcer

Resource route management instance created automatically during app initialization, refer to Resourcer for the related API.

acl

ACL instance, refer to ACL for the related API.

logger

Winston instance, refer to Winston for the related API.

i18n

I18next instance, refer to I18next for the related API.

pm

Plugin manager instance, refer to PluginManager for the related API.

version

App version instance, refer to ApplicationVersion for the related API.

middleware

Built-in middleware includes:

• logger
• i18next
• bodyParser
• cors
• dataWrapping
• db2resource
• restApiMiddleware

context

Context inherited from koa, accessible via app.context, is used to inject context-accessible content to each request. Refer to Koa Context.

NocoBase injects the following members to context by default, which can be used directly in the request handler function:

Variable Name	Type	Description
ctx.app	Application	Application instance
ctx.db	Database	Database instance
ctx.resourcer	Resourcer	Resource route manager instance
ctx.action	Action	Resource action related object instance
ctx.logger	Winston	Log instance
ctx.i18n	I18n	Internationlization instance
ctx.t	i18n.t	Shortcut of internationalized translation function
ctx.getBearerToken()	Function	Get the bearer token in the header of request

Instance Methods

use()

Register middleware, compatible with all Koa plugins.

on()

Subscribe to application-level events, mainly are related to life cycle. It is equivalent to eventEmitter.on(). Refer to events for all subscribable events.

command()

Customize command.

findCommand()

Find defined command.

runAsCLI()

Run as CLI.

load()

Load application configuration.

Signature

• async load(): Promise<void>

reload()

Reload application configuration.

install()

Initialize the installation of the application, meanwhile, install the plugin.

upgrade()

Upgrade application, meanwhile, upgrade plugin.

start()

Start application, listening will also be started if the listening port is configured, then the application can accept HTTP requests.

Signature

• async start(options: StartOptions): Promise<void>

Parameters

Name	Type	Default	Description
options.listen?	ListenOptions	{}	HTTP Listening parameters object
options.listen.port?	number	13000	Port
options.listen.host?	string	'localhost'	Domain name

stop()

Stop application. This method will deconnect database, close HTTP port, but will not delete data.

destroy()

Delete application. This methos will delete the corresponding database of application.

Events

'beforeLoad' / 'afterLoad'

'beforeInstall' / 'afterInstall'

'beforeUpgrade' / 'afterUpgrade'

'beforeStart' / 'afterStart'

'beforeStop' / 'afterStop'

'beforeDestroy' / 'afterDestroy'