webservicecreation.txt

We have been hired to create a RESTful web service to keep track of books in a local community library.
- The library works on an honor system (We are not keeping track of who checked out what or handing out late fines etc...)
- Anyone can donate a book 
- Anyone can check out a book

General tips
1. Use type annotations anytime you define a function
2. Use objects and classes whenever you can. (code is more readable and easier to refactor)

YOU WILL BE USING TDD to develop every part of this applicaiton
1. Interface
2. Tests
3. Implementation


1. Identify what Resources you are keeping track/ managing
	- In this case it is books
2. Create an ENTITY class
	- An entity is an object that is designed to be saved somewhere	
	- These classes rarely contain complex logic
	- The fields of the class are a convienient way of storing and moving information in our project
	- AN ENTITY MUST have some field that serves as an ID

3. Create A DAO for EACH entity class. 
	- DAO (Data Access Object)
	- A class that is responsible for peristing information on that entity
		- How that information gets persisted is up to the developers
		- Normally database but could be anythinig
			- Text file, NoSQL database, JPEG, 
		- We are using an python dictionary in memory to persist information
			- Very common when developing applications but in not in finished applications
	- A DAO should support the basic CRUD operation
		- CREATE
		- READ
		- UPDATE
		- DELETE
4. Create Services. Services do NOT have to be a perfect 1 to 1 with an entity
	- Services are responsible for Business logic
		- Application specific rules
			ex - Books are checked out with a 2 week return date
			- One copy of a book has to always be in the library
	- Generally two types of methods in your service
		- Wrapper methods (contain little logic and just call your DAO)
			- In general these wrapper methods do not need to be tested
		- Business logic methods which DO have logic			-