Why use a common framework for building new applications?
Reduced cost/time during the development life-cycle.
Far fewer defects will exist at any point in time after development starts.
Application development teams can be more readily scaled (re-staffed) during the development life-cycle
Reduced cost/time for all future maintenance
Allows designers & developers to focus on business functionality, instead of on common application "plumbing".
Significantly increases the overall efficiency of software development organizations.
Significantly simplifies Model Driven Design (MDD).
Encourages the use of modeling tools which in turn promotes better overall software design.
This is especially true when the modeling tool is configured to generate much of the framework code for the developer.
Why use CSLA.NET for a common base framework?
Can you create a better re-usable base application framework that other's can use?
It can very well be saving your career as a software developer!
What is CSLA.NET?
CSLA.NET is a base framework in which C# or VB.NET business applications can be built.
It provides common Business-Tier functionality that almost all custom-built applications need.
Identity and role based security.
Simplified remote or local data tier implementation.
Object persistence
Business rule enforcement
Tracking changed data
It simplifies Business-Tier and Presentation-Tier application development.
Remote or local data tier is determined via a config file setting.
Windows or table based security is determined via a config file setting.
Un-Do functionality is built-in.
Presentation Tier developer need not worry about how the underlying plumbing works.
Handles screen updates (Smart Client) when any bound business object changes its value.
Presentation developer works directly with business objects, not data sets which have been convoluted into resembling a business object.
It helps developers produce a good object-oriented design in their custom applications.
Benefits
Developers focus on Business Objects not underlying code infrastructure
Application's Class Model (Static Structure Diagram) becomes quite simple
True n-Tier framework
Applies to Desktop, Web and Web Service applications
All Business Applications will work the same way
Any developer in the organization can help on any other project and will quickly know how the unfamiliar application works.
Security: Role based user security is built-in to CSLA. Highly customizable.
Distributed Architecture. Data Tier can run on same machine as Business Tier or remotely just by changing a setting in the config file.
Desktop apps should run Data tier remotely, Intranet apps should run Data tier locally, Extranet Web apps should run Data tier remotely
No need to write a lot of code!
Your Business objects merely inherit from the base CSLA classes.
Allows your all apps to have n-Level undo capability
Handles case where multiple child elements associated with Parent; if Parent's Undo is invoked, the children objects also are "undone".
Data Tier is loosely coupled to Business Tier
Revisions of Data Tier are easily deployed without re-linking/compiling Business and Presentation tiers.
Business Rules Handling
Business Rules are encapsulated in objects. If any business rules are "broken", the object is invalidated until resolved.
Handles Transactions and Queued components
Uses Windows Services/COM+ when desired, or local DB transactions when desired.
Handles persistence of objects, collections and child objects to the Database.
Only sends updates to the DB after a particular object's data gets changed. Needless updates to DB are never performed.
Business objects fully encapsulated (Data, Data Persistence, Business methods)
Supports read-only data retrieval for lists (lookup lists) and reports (Crystal or other report generators)
What's inside CSLA.NET? CSLA Functionality Groups
Business Object Creation
Classes
BusinessBase
Base class for all editable business objects.
Functionality: n-level undo tracking broken rules dirty tracking object persistence (DB)
Supports creation of root objects and child objects.
Methods
MarkAsChild()
DataPortal_Create()
DataPortal_Fetch()
DataPortal_Update()
DataPortal_Delete()
MarkDirty() [protected]
Implements IEditableObject
Typically used for single-level undo capability.
Automatically invoked by Windows Forms when an object is bound to any form control.
BeginEdit()
CancelEdit()
EndEdit()
BusinessCollectionBase
Base class for all editable collections of business objects.
Methods
DataPortal_Create()
DataPortal_Fetch()
DataPortal_Update()
DataPortal_Delete()
Strongly typed
Add()
Item()
Remove()
Inherits from System.collections.CollectionBase
ReadOnlyBase
Base class for all non-editable objects.
ReadOnlyCollectionBase
Base class for creating immutable collections of objects.
NameValueList
Base class for retrieving name-value pairs.
Used for lookup tables or lists of read-only data (such as for drop-down box)
Used for all name-value lists instead of creating a special collection class for each type.
SafeSqlDataReader
Used to safely pull DB data columns where we don't need to differentiate between "never entered" and "empty" (or zero,"") values.
If DB row/column is Null (no value), this class returns the appropriate .NET value, such as Zero or a zero-length string.
SmartDate
Allows concept of "empty date" field in a business application.
Integrates with "SafeSqlDataReader" to support null date fields in a database.
Properties
MinimumDate
MaximumDate
N-Level undo functionality
Classes
UndoableBase
Not used directly, but is a base class for Business Base. Provides n-level undo capability to all business objects and their collections of child objects.
Methods
BeginEdit()
Each time BeginEdit() is called, the object takes a "snapshot" of itself.
CancelEdit()
Tells object to restore itself to the most recent snapshot taken by BeginEdit()
ApplyEdit()
Tells object to accept the most recent changes and permanently discards the most recent snapshot taken.
NotUndoableAttribute
Attribute to mark fields/variables as items that should not be stored in an undo snapshot.
<NotUndoable()>
Data Binding support
Used to ensure all data-bound Presentation controls are refreshed whenever any related business object values are changed.
Simply add a hidden control on a Windows Form bound to our business class's "IsDirty" property.
Classes
BindableBase
Base class for UndoableBase (then BusinessBase)
Methods
OnIsDirtyChanged()
Raises IsDirtyChanged event so UI knows it needs to refresh all of its data-bound controls
Called whenever the business object's MarkDirty() method is called (MarkDirty must always be called by our business logic any time the internal state our the object changes.)
BindableCollectionBase
Base class for BusinessCollectionBase
Implement IBindingList interface so that ListChanged event will be fired.
ListChanged event is marked as [field: NonSerialized()]
Business Rule Tracking
Used to track broken business rules. Marks an object as invalid until all broken rules are resolved. Also provides a read-only list of broken rules to the UI developer for display to end-user (or other reason).
Classes
BrokenRules
Includes methods used by BusinessBase to mark rules as being broken or not. BrokenRules simply contains a collection of rule names and descriptions that are created and managed by our business objects.
RulesCollection
Rule
Data Portal
Used for object persistence. Enables applications to simply set a configuration setting to indicate if the data tier is running locally or on a remote application server.
Benefits
Allows for new business objects being added (or revised) without necessarily forcing a revision of all the proxy information on the client workstations.
Centralized Security when calling the application server.
A consistent object persistence mechanism
Toggle between running the data access locally or via remoting.
Business objects can check user's identity and role on both client and server.
Client-side Classes
DataPortal
Used for object persistence services. Can use ADO.NET or any other data tier to connect to the target database.
Methods
Create()
For creating new business objects with default values that come from the database
Fetch()
Update()
Delete()
Features
Local or remote data access
Table-based or Windows security
Transactional or non-transactional data access on method by method basis.
Includes code to pass user's identity info to server on each call when table-based security is enabled.
Used by (classes)
BusinessBase
BusinessCollectionBase
ReadOnlyCollectionBase
ReadOnlyBase
Server-side Classes
These objects carry out the persistence orders for fetch, create, update, delete.
Hosted by IIS when configured for running on remote application server.
Server.DataPortal
Server.ServicedDataPortal.DataPortal
Installed within Enterprise Services COM+ for 2 phase commit.
Marked as "Requires Transaction" in COM+
Uses <AutoComplete()> attribute
Only one component gets registered in COM+ and all our other components are protected by transactions.
Should really only be used when transaction support between databases is required.
Helper Classes
Criteria
Provides the criteria or key parameters by which to find objects persisted in the database.
Used instead of passing a parameter list to the Fetch() method for example.
Allows a single DataPortal object to be able to handle all our business objects persistence needs.
Is nested within the Business Objects
Transactional / non-Transactional data access
Table-based Security
Used only when built-in Windows Security will not be used.
Security object is passed to Server-Side Data Portal for user validation (table based security only)
Classes
Security.Identity
Uses IIdentity interface
Security.Principal
Uses IPrincipal interface
About
Title
CSLA.NET Component-based Scaleable Logical Architecture
Subject
-
Company
-
Author
Roy Ogborn
Version
112
Comments
-