Portable Component Model for Node.js

This module is a part of the Pip.Services polyglot microservices toolkit.

It defines a portable component model interfaces and provides utility classes to handle component lifecycle.

The module contains the following packages:
- Build - basic factories for constructing objects
- Config - configuration pattern
- Refer - locator inversion of control (IoC) pattern
- Run - component life-cycle management patterns

Quick links:

* Configuration Pattern
* Locator Pattern
* Component Lifecycle
* API Reference
* Change Log
* Get Help
* Contribute

Use

Install the NPM package as
``bash
npm install pip-services4-components-node --save
`

Then you are ready to start using the Pip.Services patterns to augment your backend code.

For instance, here is how you can implement a component, that receives configuration, get assigned references,
can be opened and closed using the patterns from this module.

`typescript
import { IConfigurable } from 'pip-services4-components-node';
import { ConfigParams } from 'pip-services4-components-node';
import { IReferenceable } from 'pip-services4-components-node';
import { IReferences } from 'pip-services4-components-node';
import { Descriptor } from 'pip-services4-components-node';
import { IOpenable } from 'pip-services4-components-node';

export class MyComponentA implements IConfigurable, IReferenceable, IOpenable {
private _param1: string = "ABC";
private _param2: number = 123;
private _anotherComponent: MyComponentB;
private _opened: boolean = true;

public configure(config: ConfigParams): void {
this._param1 = config.getAsStringWithDefault("param1", this._param1);
this._param2 = config.getAsIntegerWithDefault("param2", this._param2);
}

public setReferences(refs: IReferences): void {
this._anotherComponent = refs.getOneRequired(
new Descriptor("myservice", "mycomponent-b", "", "", "1.0")
);
}

public isOpen(): boolean {
return this._opened;
}

public open(context: IContext, callback: (err: any) => void): void {
this._opened = true;
console.log("MyComponentA has been opened.");
callback(null);
}

public close(context: IContext, callback: (err: any) => void): void {
this._opened = true;
console.log("MyComponentA has been closed.");
callback(null);
}

}
`

Then here is how the component can be used in the code

`typescript
import { ConfigParams } from 'pip-services4-components-node';
import { References } from 'pip-services4-components-node';
import { Descriptor } from 'pip-services4-components-node';

let myComponentA = new MyComponentA();

// Configure the component
myComponentA.configure(ConfigParams.fromTuples(
'param1', 'XYZ',
'param2', 987
));

// Set references to the component
myComponentA.setReferences(References.fromTuples(
new Descriptor("myservice", "mycomponent-b", "default", "default", "1.0",) myComponentB
));

// Open the component
myComponentA.open("123", (err) => {
console.log("MyComponentA has been opened.");
...
});
`

If you need to create components using their locators (descriptors) implement
component factories similar to the example below.

`typescript
import { Factory } from 'pip-services4-components-node';
import { Descriptor } from 'pip-services4-components-node';

export class MyFactory extends Factory {
public static myComponentDescriptor: Descriptor = new Descriptor("myservice", "mycomponent", "default", "*", "1.0");

public MyFactory() {
super();

this.registerAsType(MyFactory.myComponentDescriptor, MyComponent);
}
}

// Using the factory

let myFactory = MyFactory();

let myComponent1 = myFactory.create(new Descriptor("myservice", "mycomponent", "default", "myComponent1", "1.0");
let myComponent2 = myFactory.create(new Descriptor("myservice", "mycomponent", "default", "myComponent2", "1.0");

...
`

Develop

For development you shall install the following prerequisites:
* Node.js 14+
* Visual Studio Code or another IDE of your choice
* Docker
* Typescript

Install dependencies:
`bash
npm install
`

Compile the code:
`bash
tsc
`

Run automated tests:
`bash
npm test
`

Generate API documentation:
`bash
./docgen.ps1
`

Before committing changes run dockerized build and test as:
`bash
./build.ps1
./test.ps1
./clear.ps1
``

Contacts

The module is created and maintained by Sergey Seroukhov and Danil Prisyazhniy.

The documentation is written by:
- Egor Nuzhnykh
- Alexey Dvoykin
- Mark Makarychev
- Eugenio Andrieu