bmax-service-containers

JavaScript app service containers

Description

Container classes for storing services as Singleton or as Factory.

• Singletons are instanced once during the 'set' method.
• Factories are instanced during the 'get' method.

The package provides the following service containers:

• ServiceContainer
  • Local service container
  • Must be instanced with new ServiceContainer()
  • Musst be passed down via e.g. the react context api or a express middleware
• GlobalServiceContainer
  • Global service container
  • Instances itself once and is available over the whole application
  • Just needs to be imported
  • Disadvantage: Can override itself in a microservice architecture
  • If this is used, it is recommended to namespace your service names

Installation

$ npm i -S bmax-service-containers

Usage

The following section is showing the usage of GlobalServiceContainer. The ServiceContainer can also be used like this but it needs to be instanced first.

To add a service:

import { GlobalServiceContainer } from 'bmax-service-containers';
import MyService from './MyService';
 
// Namespace the service
const MY_SERVICE = 'MyApp.MyService';
 
// The service will be set as singleton by default
GlobalServiceContainer.set(MY_SERVICE, MySerivce);
 
// To set a service as factory
GlobalServiceContainer.set(MY_SERVICE, MySerivce, 'factory');

The set method expects 2-3 arguments: GlobalServiceContainer.set(servceName: string, ServiceClass, serviceType: string = 'singleton');

Every argiment after the third is passed to the constructor of the service class.

To get a service:

import { GlobalServiceContainer } from 'bmax-service-containers';
 
// Namespace the service
const MY_SERVICE = 'MyApp.MyService';
 
// The service will be set as singleton by default
const theService = GlobalServiceContainer.get(MY_SERVICE);
 
// If the service is a factory
GlobalServiceContainer.set(MY_SERVICE, MySerivce, 'factory');

The set method expects 1 arguments GlobalServiceContainer.get(servceName: string);

Every argiment after the first is passed to the constructor of the service class.

To delete a service:

import { GlobalServiceContainer } from 'bmax-service-containers';
 
// Namespace the service
const MY_SERVICE = 'MyApp.MyService';
 
// The service will be set as singleton by default
GlobalServiceContainer.unset(MY_SERVICE);

To check if a service is available:

import { GlobalServiceContainer } from 'bmax-service-containers';
 
// Namespace the service
const MY_SERVICE = 'MyApp.MyService';
 
// The service will be set as singleton by default
if (GlobalServiceContainer.has(MY_SERVICE)) {
    // TODO: Sonething...
}