Click here to Skip to main content
Click here to Skip to main content
Go to top

Business Objects for CodeSmith

, 23 Nov 2004
Rate this:
Please Sign up or sign in to vote.
Save time when developing large applications, by using code generation for your business objects.

Sample Image - BusnessObjectGenerator.gif

Introduction

One of the biggest issues a developer faces when developing a large application, is maintaining design standards and methods. Design documents, coding standards, and code review were the only tools a developer had to work with in the golden days of coding. With the birth of code generators such as CodeSmith, development teams are now armed with a powerful tool to expedite the development process and maintain a standard throughout the application. When developing applications, templates can save you a lot of time by using common design patterns for generating different business objects. By definition, templates are repeatable patterns, which can be derived from any design methods. The benefit of using templates in code generation is the ability to enforce design methods and standards while saving development costs for any application. This article will present a basic design pattern and the templates to generate code for the design pattern.

Business Object Design Pattern

Business objects contain properties that reflect data; you will find objects named invoice, invoice detail, etc. Commonly, they include embedded relationships -- for example, an invoice object may have a property that retrieves the details for that invoice instance.

Based on this simple observation, we can develop a design standard for our business objects:

  • Business Objects Contain Properties
  • Business Objects Require Collections
  • Business Objects Require Access Data

Business Object:

The Business Object Class Template (ClassGenerator.cst) is used to create a business object’s properties and methods. A standard set of methods for accessing the object's data will be generated for each object defined in an XML document. The following methods will be created for each business object defined:

Public Static Methods
  • CreateNewObject: Creates a new Object.
  • DeleteObject: Deletes an Object.
Public Instance Constructors
  • Object - Overloaded. Initializes a new instance of the Object class.
Public Instance Methods
  • Copy: Copies an Object.
  • Delete: Deletes an Object.
  • Fetch: Fetches an Object.
  • Save: Saves an Object.
  • Update: Updates an Object.

Business Object Collection:

The Business Object Collections Template (CollectionGenerator.cst) is used to create a collection class for each business object. The collection object uses the 'CollectionBase' as the base class. The following methods will be created for each business object defined:

Public Instance Constructors
  • ObjectCollection: Constructor initializes a new instance of the ObjectCollection class.
Public Instance Properties
  • Count: Gets the number of elements contained in the CollectionBase instance.
  • Item: Gets or sets the value associated with the specified key.
Public Instance Methods
  • Add: Adds an item to the Object Collection.
  • Contains: Determines whether the Object Collection contains a specific Object.
  • IndexOf: Determines the index of a specific item in the Object Collection.
  • Insert: Inserts an item to the Object Collection at the specified position.
  • Remove: Removes the first occurrence of Object in the Object Collection.
Protected Instance Methods
  • OnInsert: Validates before inserting a new Object into the Object Collection.
  • OnRemove: Validates before removing a new Object from the Object Collection.
  • OnSet: Validates before setting an Object in the Object Collection.
  • OnValidate: Performs additional custom processes when validating an Object.

Business Object Data:

The Business Object Data Class Template (DataClassGenerator.cst) is used to define the data access layer for each business object. The following methods will be created for each business object defined:

Public Instance Constructors
  • ObjectData: Constructor initializes a new instance of the ObjectData class.
Public Instance Methods
  • CreateNewObject: Creates a new Object in the database.
  • DeleteObject: Deletes an Object from the database.
  • FetchObject: Gets a single Object from the database.
  • UpdateObject: Updates an Object in the database.

Base Object Classes:

The Business Object Base Class Template (BaseObjectClass.cst) is used to create the base class for each business object. The following are the properties used for each business object:

Public Instance Properties
  • Id: ID of Business Object.
  • Name: Name of Business Logic Object.
Internal
  • GenerateObjectId: Generates an ID for the given object.

Base Object Data Class

The Business Object Base Data Class Template (BaseDataClass.cst) is used to create the base class for each business object. The following are the properties used for each business object:

Public Instance Constructors
  • BaseDataClass: Constructor initializes a new instance of the BaseDataClass class.
Public Instance Properties
  • ConnectionString: Gets Connection String configuration from a config file.
Public Instance Methods
  • AddParamToSQLCmd: Adds a parameter to a SqlCommand.
  • ExecuteCollectionReader: Returns an object collection from a SQL Data Reader.
  • ExecuteObjectReader: Returns an object from a SQL Data Reader.
  • ExecuteReaderCmd: Generates Object Collection from SQL Data Reader.
  • ExecuteScalarCmd: Executes a query.
  • SetCommandType: Sets the CommandText property to the name of the stored procedure.

Data Layer Generator:

The Data Layer Template (DataGenerator.cst) is used to create the required database objects needed to support the business objects.

Procedures
  • Object_Create: Creates a new Object in the database.
  • Object_Delete: Deletes an Object from the database.
  • Object_Fetch: Gets a single Object from the database.
  • Object_Update: Updates an Object in the database.

Using the Generator

Based on a definition provided by an XML Document, the generator will produce code for your business object, business object collection, business object data access, business object tables, and stored procedures.

Business Objects Attributes

attribute

maps to

remarks

class

table

name will represent the table name

property

column

name will represent the column name

Class Attributes

attribute

remarks

name

represents the table name

Property Attributes

attribute

remarks

name

represents the column name

type

represents a system type or a business object collection

maxSize

 
Supported Types

C# Type

Maps to SQL type

string

nvarchar

int

int

DateTime

smalldatetime

bool

bit

decimal

money

Defining the Business Objects:

Let's create a simple Invoice Business Object. The invoice object will contain a customer name, invoice date, invoice paid status, and line items. The following XML document defines the objects:

<?xml version="1.0" encoding="utf-8" ?> 
<BusinessObjects xmlns="http://www.austinconnergroup.com">
  <class name="Invoice">  
    <properties>
      <property name="Id" type="String" maxSize="36" />
      <property name="Customer" type="String" maxSize="96" />
      <property name="InvoiceDate" type="DateTime" maxSize="" />
      <property name="InvoicePaid" type="bool" maxSize="" />
      <property name="InvoiceDetails" type="InvoiceDetailCollection" maxSize="" />
    </properties>
  </class>
  <class name="InvoiceDetail">  
    <properties>
      <property name="Id" type="String" maxSize="36" />
      <property name="InvoiceId" type="String" maxSize="36" />
      <property name="LineItem" type="Int" maxSize="" />
      <property name="ItemDescription" type="String" maxSize="96" />
      <property name="ItemCostPerUnit" type="Single" maxSize="" />
      <property name="ItemQuanity" type="Int" maxSize="" />
      <property name="ItemUnit" type="String" maxSize="8" />
    </properties>
  </class>
</BusinessObjects>

In our definition document, we define two objects, Invoice and InvoiceDetail. You will notice that the Invoice object contains a property InvoiceDetails which is of the type InvoiceDetailCollection. This defines a relationship between InvoiceDetail and Invoice, and will produce the required methods and SQL statements for this relationship.

Running the Generator

Once we have our model, we are ready to generate our code. BuildTemplate.cst is the main entry point for generating the code for all the business objects, and has the following properties:

  • XmlFile - XML Document that the classes will be generated from.
  • OutputDirectory - The base directory for code output.
  • GenerateBaseClasses - Set true to generate base classes.
  • RootNamespace - The root namespace generated classes will be a member of.
  • ObjectNamespace - The object namespace generated classes will be a member of.
  • BusinessLogicNamespace - The business object namespace generated classes will be a member of.
  • DataAccessNamespace - The data object namespace generated classes will be a member of.
  • DeveloperName - Developer's name.
  • CompanyName - Company name.

Points of Interest

The article here presents the prototype that I developed for proof of concept. After writing the generator and supporting templates, I was so amazed at the results, I immediately wrote the templates for our team and deployed them into our production environment. One of the biggest benefits was not the cost savings in time, but the fact that all the generated code was self documenting. This fact alone was worth the efforts in creating these templates. The biggest battle I faced everyday was the lack of documented code, now it's a snap.

History

  • 11/23/2004 - Initial article.

License

This article, along with any associated source code and files, is licensed under The Microsoft Public License (Ms-PL)

Share

About the Author

JR Hull
Web Developer
United States United States
Software Architect with 20++ years of software design and development experience with a strong hold in Object-Oriented software engineering using UML with Design Patterns. Architected and developed several industrial software packages and passed through full software development life-cycle. Currently managing a small group of developers, developing management software for the agriculture industry.

Comments and Discussions

 
GeneralRe: VB version of Editor property attribute PinmemberJR Hull16-Dec-04 7:25 
GeneralFxCop PinmemberSimonMDB11-Dec-04 14:16 
GeneralRe: FxCop PinmemberBill_Philly12-Dec-04 15:02 
GeneralRe: FxCop PinmemberSimonMDB12-Dec-04 15:54 
GeneralRe: FxCop PinmemberJR Hull13-Dec-04 3:28 
GeneralPossible extensions?! PinmemberSimonMDB6-Dec-04 13:01 
GeneralRe: Possible extensions?! PinmemberJR Hull7-Dec-04 2:54 
GeneralRe: Possible extensions?! PinmemberSimonMDB9-Dec-04 16:15 
GeneralRe: Possible extensions?! PinmemberJR Hull10-Dec-04 2:38 
Generalfailed Pinmembersteel8411-Dec-04 20:02 
GeneralRe: failed PinmemberJR Hull2-Dec-04 2:33 
GeneralRe: failed PinmemberBrandon Hunt3-Dec-04 9:05 
GeneralRe: failed Pinmemberangel.carrillo7-Dec-04 3:20 
GeneralRe: failed PinmemberBrandon Hunt7-Dec-04 3:43 
GeneralRe: failed PinmemberJR Hull7-Dec-04 3:45 
GeneralGreat PinmemberVictor Vogelpoel24-Nov-04 1:17 
GeneralRe: Great Pinmemberdequbed24-Nov-04 2:20 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Mobile
Web03 | 2.8.140926.1 | Last Updated 23 Nov 2004
Article Copyright 2004 by JR Hull
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid