pip_services4_components 0.0.1

Components patterns for Pip.Services in Dart. This framework is part of the [Pip.Services](https://github.com/pip-services/pip-services) project.

Portable Component Model for Dart

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:

• Logging

• Configuration

• API Reference

• Change Log

• Get Help

• Contribute

• Examples

• Warning! Config package now not work with condition {{#if var}} something {{/}} in config files. Use Mustache syntax, for example {{#var}} something {{/var}}

Use

Add this to your package's pubspec.yaml file:

dependencies:
  pip_services4_components: version

Now you can install package from the command line:

pub get

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.

class MyComponentA implements IConfigurable, IReferenceable, IOpenable {
  MyComponentA();

  String _param1 = 'ABC';
  int _param2 = 123;
  MyComponentB _anotherComponent;
  bool _opened = true;

  @override
  void configure(ConfigParams config) {
    this._param1 = config.getAsStringWithDefault('param1', this._param1);
    this._param2 = config.getAsIntegerWithDefault('param2', this._param2);
  }

  @override
  void setReferences(IReferences refs) {
    this._anotherComponent = refs.getOneRequired<MyComponentB>(
      Descriptor('myservice', 'mycomponent-b', '*', '*', '1.0')
    );
  }

  @override
  bool isOpen() {
    return this._opened;
  }

  @override
  Future open(IContext? context) {
    return Future(() {
      this._opened = true;
      print('MyComponentA has been opened.');
    });
  }

  @override
  Future close(IContext? context) {
    return Future(() {
      this._opened = true;
      print('MyComponentA has been closed.');
    });
  }
}

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

import 'package:pip_services3_commons/src/config/ConfigParams.dart';
import 'package:pip_services3_commons/src/refer/References.dart';
import 'package:pip_services3_commons/src/refer/DependencyResolver.dart';

var myComponentA = MyComponentA();

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

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

// Open the component
myComponentA.open(Context.fromTraceId('123'));

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

import 'package:pip_services3_components/src/build/Factory.dart';
import 'package:pip_services3_commons/src/refer/Descriptor.dart';

class MyFactory extends Factory {
  static Descriptor myComponentDescriptor =
      Descriptor('myservice', 'mycomponent', 'default', '*', '1.0');

  MyFactory() : super() {
    registerAsType(MyFactory.myComponentDescriptor, MyComponent);
  }
}

// Using the factory

MyFactory myFactory = MyFactory();

MyComponent1 myComponent1 = myFactory.create(
    Descriptor('myservice', 'mycomponent', 'default', 'myComponent1', '1.0'));
MyComponent2 myComponent2 = myFactory.create(
    Descriptor('myservice', 'mycomponent', 'default', 'myComponent2', '1.0'));
...

Develop

For development you shall install the following prerequisites:

• Dart SDK 3
• Visual Studio Code or another IDE of your choice
• Docker

Install dependencies:

pub get

Run automated tests:

pub run test

Generate API documentation:

./docgen.ps1

Before committing changes run dockerized build and test as:

./build.ps1
./test.ps1
./clear.ps1

Contacts

The library is created and maintained by Sergey Seroukhov and Levichev Dmitry.

The documentation is written by Egor Nuzhnykh, Alexey Dvoykin, Mark Makarychev, Levichev Dmitry.