Service-Layer

Realization of Service Layer pattern

Table of Contents

• Service-Layer
  • Table of Contents
    • Installation
    • Usage
    • Documentation
    • License

Installation

    npm install github:Maxwell88/service-layer

or

    yarn add github:Maxwell88/service-layer

Usage

// serviceLayer.js
import { ServiceLayer } from "service-layer";
const koaResolver = result => this.body = result;
const koaArgsBuilder = args => args[0];
export const new ServiceLayer(
    koaResolver,
    koaArgsBuilder
    {
        before:[
            /* Your before rules for example: */
            {
                name: "exampleRequireRule",
                type: "require",
                execute: (ctx,args,serviceData) => {
                    /*
                        rule logic and return changed context to another rule 
                        or if it last than to service
                    */
                    return ctx
                }

            }
        ],
        after: [
            /* Your after rules */
        ]
    }
});

// router.js
import Router from "koa-router";

import ServiceLayer from "./serviceLayer";
import ExampleServiceClass from "./ExampleServiceClass";

const router = new Router({ prefix: config.PREFIX });

router.post("/example", ServiceLayer.useService(ExampleServiceClass));

export default router;

// router.js
import { Service } from "service-layer";

export default class Create extends Service {
    
    /*
        there you can iniate your required and custom rules for example:
    */
    static exampleRequireRule = "simple args"
    static exampleCustomRule = "simple args"

    async execute(ctx) {
        /*
            service logic
        */
        let result;
        return result; // return data to resolver
    }
}

Documentation

• Service Layer

  constructor(resolver:function, argumentBuilder: function, rules: object): ServiceLayer useService(service: Service): Function

  1. argumentBuilder - function that have one field that is array of arguments that receives middleware of Koa/express/hapi etc. and must return changed context that would been used at future.

  2. resolver - function that have one argument - result, that argument contain a final result of service, this of resolver is a context from argumentsBuilder . Rules don`t have influence at resolver this

  3. rules - object that have two field before:array and after:array with objects of rule that have 3 required field name, type, execute:

     Key	Type	Required	Note
     name	String	+	Name of rule, and name of static param for Service class if type of rule not hidden
     type	one of hidden, required or custom strings	+	type of function behavior . hidden - execute always, don`t use static field of Service class, required - execute always, static field of Service class is required otherwise RULE_IS_REQUIRED exeption, custom - execute only if static field is not empty
     execute	Function	+	Name of rule, and name of static param for Service class

• Service

  Service class for inheritance with required execute: function field (look usage).

• Exeption

  constructor(data: object): Error The data object has the following fields:

  Key	Type	Required	Note
  fields	object with string fields or empty	+	Errored fields
  code	String	+	Exeption code

License

Licensed under the MIT license.