ClawjectApplicationContext

ClawjectApplicationContext is an object that stores and manages configurations and beans of the application.

Usage

Let's define a simple application with a single bean and try to expose it using ExposeBeans function:

import { ClawjectApplication, ClawjectFactory, Bean, ExposeBeans } from '@clawject/di';

class Cat {
  constructor(
    public readonly id: string,
  ) {}

  public meow() {
    console.log('Meow!');
  }
}

class CatRepository {
  constructor(
    //...
  ) {}

  findById(id: string): Cat {
    // ...
  }
}

@ClawjectApplication
class Application {
  catRepository = Bean(CatRepository);

  exposed = ExposeBeans<{ repository: CatRepository }>();
}

const applicationContext = await ClawjectFactory.createApplicationContext(Application);
const repository = await applicationContext.getExposedBean('repository');

In this example, we have defined a simple application with a single bean CatRepository and exposed it using ExposeBeans function. We can then access the exposed bean using getExposedBean method of the ClawjectApplicationContext object.

Also, we can get all exposed beans using getExposedBeans method:

@ClawjectApplication
class Application {
  catRepository = Bean(CatRepository);
  catService = Bean(CatService);

  exposed = ExposeBeans<{ repository: CatRepository, service: CatService }>();
}

const applicationContext = await ClawjectFactory.createApplicationContext(Application);
const exposedBeans = await applicationContext.getExposedBeans();

console.log(exposedBeans.repository);
console.log(exposedBeans.service);

After running this code, we will see the CatRepository and CatService objects in the console.

Now let's define some initialization and destruction logic for our beans using @PostConstruct and @PreDestroy decorators:

@ClawjectApplication
class Application {
  dbConnection = Bean(DBConnection);

  @PostConstruct
  onInit(dbConnection: DBConnection) {
    dbConnection.connect();
    console.log('DBConnection initialized');
  }

  @PreDestroy
  onDestroy(dbConnection: DBConnection) {
    dbConnection.close();
    console.log('DBConnection closed');
  }
}

const applicationContext = await ClawjectFactory.createApplicationContext(Application);
// Will print 'DBConnection initialized'

await applicationContext.destroy();
// Will print 'DBConnection closed'

Methods overview

.getExposedBean(exposedBeanName: string)

Returns the exposed bean instance by the given name.

import { Bean, ClawjectApplication, ClawjectFactory, ExposeBeans } from "@clawject/di";

interface Foo { value: 'foo' }
interface Bar { value: 'bar' }

@ClawjectApplication
class Application {
  @Bean foo: Foo = {value: 'foo'};
  @Bean bar: Bar = {value: 'bar'};

  exposed = ExposeBeans<{ exposedBean: Foo }>()
}

const application = await ClawjectFactory.createApplicationContext(Application);
const exposedBean = await application.getExposedBean('exposedBean');

console.log(exposedBean.value); // 'foo'

.getExposedBeans()

Returns all exposed beans.

import { Bean, ClawjectApplication, ClawjectFactory, ExposeBeans } from '@clawject/di';

interface Foo { value: 'foo' }
interface Bar { value: 'bar' }

@ClawjectApplication
class Application {
  @Bean foo: Foo = {value: 'foo'};
  @Bean bar: Bar = {value: 'bar'};

  exposed = ExposeBeans<{ exposedBean1: Foo, exposedBean2: Bar }>();
}

const application = await ClawjectFactory.createApplicationContext(Application);
const exposedBeans = await application.getExposedBeans();

console.log(exposedBeans); // { exposedBean1: { value: 'foo' }, exposedBean2: { value: 'bar' } }

.destroy()

Destroys the application context and destroys all beans. Functions annotated with @PreDestroy will be called for all beans.

import { Bean, ClawjectApplication, ClawjectFactory, PreDestroy } from '@clawject/di';

class Foo {
  @PreDestroy
  preDestroy() {
    console.log('destroy foo');
  }
}

@ClawjectApplication
class Application {
  foo = Bean(Foo);

  @PreDestroy
  preDestroy() {
    console.log('destroy application');
  }
}

const application = await ClawjectFactory.createApplicationContext(Application);
await application.destroy();
// prints: 'destroy foo'
// prints: 'destroy application'