doing something useful with enterprise library 3.0 benjamin day level: intermediate
TRANSCRIPT
About the speaker
Owner, Benjamin Day Consulting, Inc.– Email: [email protected]– Web: http://www.benday.com– Blog: http://blog.benday.com
Trainer– Visual Studio Team System, Team Foundation
Server Microsoft MVP for C# Microsoft VSTS/TFS Customer Advisory
Council Leader of Beantown.NET INETA User
Group
Why Enterprise Library?
Why not?– Why write and re-write common application
code?
Focus on solving the core business problem
Microsoft solved it for you– Standardized solution– Hooks in nicely with .NET through configs
It’s free http://codeplex.com/entlib
Caching
Security
Data Access
Logging
ExceptionHandling
Ent Lib 3.0 – Application Blocks
Plug-inConfig
Helpers & Design
Instrumen-tation
ObjectBuilder
Cryptography
Core
Policy InjectionValidation
http://tinyurl.com/3d8xfw
Data Access Block
Wraps common actions for database access
Handles closing of connections, IDispose calls
Some degree of database independence
Relatively easy to understand
Adopting Enterprise Library
Why is this talk titled“Doing Something Useful…”?
Can be like swimming in the Atlantic at low tide in the spring
What does this have to do with the Data Access Block?
Does it have to be so difficult?
My $0.02 on where begin
Start with the Policy Injection Block– Allows you to defer decisions on other blocks
Configure PIB to use logging– Simple way to debug your configuration
Exception Handling Block– (eat your vegetables)
Caching– Fix performance problems
Policy Injection Block
Layer of abstraction Lets you hook functionality in at runtime
via config Intercepts calls in to an object’s
methods Think aspect-oriented programming or
dependency injection for methods
Getting started with the PI block
Two ways to use Policy Injection:– Objects extend from MarshalByRef– Code against interfaces instead of concrete
classes
Add references– Microsoft.Practices.EnterpriseLibrary.PolicyInjec
tion– Microsoft.Practices.ObjectBuilder– Microsoft.Practices.EnterpriseLibrary.CallHandle
rs– Plus, whatever block you’ll reference from PI
Edit app.config/web.config with EntLibConfig.exe
Calling into the PI framework
Call PolicyInjection.Create<T>() or one of the overloads
Returns a wrapper to your object Call your methods through the wrapper
Configuration
EntLibConfig.exe Uses the
Remoting Policy Injector
Policy consists of– Matching Rules– Handlers
Logging Handler
Through policy injection framework, intercepts calls
Writes message to log before and/or after
Logging Application Block
Logs activity in your app
Trace Listeners– Where does it
get stored?
Formatters– How does it get
stored?
Filters– What to write?
Exception Handling Block
Allows you to define how to treat exceptions
Option: Catch and re-throw different exception
Option: Eat the exception
About the Validation Block
Allows you to validate access to your objects
Validation logic can be stored outside of your objects in the configs
Validation can also be defined via attributes
Similar to a rules engine– Think Windows Workflow Rules “light”
Available Validators
And Composite Contains
Characters Date Time
Range Domain Enum
Conversion Not Null Object
Collection
Object Validator Or Composite Property
Compare Range Validator RegEx Relative Date
Time String Length Type Conversion
Common Validator Fields
MessageTemplate– Provides a human-readable error message– Overrides the default implementation
MessageTemplateResourceName– Enables messages in resource files
MessageTemplateResourceType Negate
– If statement evaluates to true rule fails– false succeeds
Tag– Category for the validation
Message Template Tokens
Think String.Format() Use these to create custom messages {0}
– Original value being validated
{1}– “Key” for the value– If property or field name (m_id or Id)– If object null
{2}– The tag value if available
Service Layer Pattern
From “Patterns Of Enterprise Application Architecture”by Martin Fowler, Randy Stafford, et al.Chapter 9
“Defines an application’s boundary with a layer of services that establishes a set of available operations and coordinates the application’s response in each operation.”
-Randy Stafford
The Caching Block
Allows you to cache return values from method, properties
Easy to add with the Policy Injection Block
Summary
Policy Injection Block Helps Speed Adoption
Logging Block Exception Handling Block Exception Handling in WCF Validation Block Caching Block
About the speaker
Owner, Benjamin Day Consulting, Inc.– Email: [email protected]– Web: http://www.benday.com– Blog: http://blog.benday.com
Trainer– Visual Studio Team System, Team Foundation
Server Microsoft MVP for C# Microsoft VSTS/TFS Customer Advisory
Council Leader of Beantown.NET INETA User
Group