Service Oriented Computing

SOURCE: SOA Principles of Service Design

CRM - Create Entity Srv - MDM

Dependency Injection

Scott wrote a nice intro article here.

Usuall code to access database from Biz Service. Shows dependency of db in bizService.

There 2 types of Dependency - Opaque / Transparent


Opaque below - hard to test...for ex. you want to test without accessing the actual db instead use a fakeDb...its hard in this case.

Transparent
- dependency in case is INVERTED, it is asigned from outside.
- it is passed as a constructor argument
- easy to test...now you can pass a fakeDb object to test

to make it even more easy to test, consider the following change:

Now lets look at various ways to instantiate the object

ER Notations

ZERO throught MANY


ONE throught MANY

ONE and ONLY ONE
- Two dashes it indicates that the first entity can have one and only one of the second
- specifically it cannot have zero,
- and it cannot have more than one

ZERO or ONE
- the first entity can have zero or one of the second, but not more than one


MANY to MANY


SOURCE: http://rapidapplicationdevelopment.blogspot.com/2007/06/entity-relationship-diagram-example.html

Employee Management Object graph

Seven Wastes - Toyota Product System

PageRank

If a famous doctorX (Recommender) refer (recommends) another doctorY (recommendee) it adds more weight than some unknown 20 people folks refer doctorY

PageRank = a web page is important if pointed to by another important page.

It is a score (PageRank Score) that indicates popularity (aka Popularity Score).