Commons module

Provides a set of tools used in microservices or backend services, and it is designed to facilitate symmetric implementation accross different programming languages.

Packages

The module contains the following packages:

Convert - portable value converters
Data - data patterns
Errors - application errors
Reflect - portable reflection utilities

Use

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

dependencies:
  pip_services4_commons: 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('123');