Enterprise Library

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Enterprise Library
John Viner .NET MCP Solutions Architect, SoftTeq
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History

• Avanade ACA.Net (Microsoft and Accenture JV) -
  2002
• MS Patterns and Practice Individual Application
  Blocks
• Enterprise Library V1.0 Jan 2005
• Enterprise Library V2.0 (.Net 2.0) Jan 2006

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Why?

• Provides mechanisms to accomplish common code
  tasks using libraries designed to showcase best
  practices
• Contains a Library of reusable software assets to
  address common enterprise development challenges
• Has a strong focus on consistency,
  extensibility, ease of use and integration

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The Blocks and Tools

• Data Access Application Block (DAAB)
• Logging Application Block
• Exception Handling Application Block
• Cryptography Application Block
• Caching Application Block
• Security Application Block
• All come with source, unit tests and QuickStart
  Projects
• Plus Enterprise Library Configuration Console

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Configuration Console

• Open a web.config or an app.config
• Enterprise Library config written to web.config
  or separate config file

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Need Data Access Application Block?Is your team

• Writing (cutting and pasting) the same data
  access code throughout your data access layer
• Matching stored procedure parameter definitions
  with the calling application code
• Wondering if your code is properly closing
  connections
• Writing a component to make it simpler to call
  stored procedures
• Wrestling with where/how to store connection
  string information

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Data Access Application Block cont.

• Provides simplified access to the most common
  data access operations (reduced code and
  possibility for errors)
• Database db DatabaseFactory.CreateDatabase()
• DbCommand dbCommand db.GetStoredProcCommand("Get
  ProductsByCategory")
• db.AddInParameter(dbCommand, "CategoryID",
  DbType.Int32, customerID)
• IDataReader reader db.ExecuteReader(dbCommand)
  
• or
• DataSet customerDS db.ExecuteDataSet(GetCustome
  rByID, customerID)
• Handles housekeeping tasks managing DBCommand
  and DbConnection, caching parameters

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Data Access Application Block cont.

• Transparency when developing for multiple types
  of databases
• An easy way to adjust and validate the database
  configuration settings
• Improve consistency
• Improve ease of use

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Need Logging Application Block?Is your team

• Writing a component to make it simpler to log and
  trace application information
• Different groups in your enterprise writing new
  and improved logging systems
• Having multiple logging systems in different
  layers of the application
• A component that logs locally, but doesnt extend
  to a distributed logging system
• Inflexible configuration options for logging
• Recompiling code to change logging behavior

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Logging Application Block cont.

• Allows applications to log business and
  operations data to various destinations, which
  are externally configurable
• Configuration specifies which messages go where,
  and how they are formatted
• Formatters and sinks are extensible. Out of the
  box Event Log, Database, Text File, MSMQ
  (asynchronous), E-mail, WMI and Windows Event
  Tracing
• Logger.Write("Customer " customerID "
  deleted.", Data Access, 4)

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Need Exception Handling App Block?Is your team

• Writing the same exception logging code is pasted
  throughout your code in catch blocks
• Has difficulty in ensuring exception handling
  actions are consistent from developer to
  developer, and application to application
• Changing your policy regarding exception handling
  results in source code changes

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Exception Handling App Block cont.

• Facilitates consistent exception handling
  behavior at logical boundaries of an application
• Actions are extensible provides Logging,
  Wrapping one exception with another, and
  Replacing one exception with an other
• Allows the creation of exception policies which
  dictate which actions should be taken for
  specific exception types at the logical boundary
• Example All security exceptions arising from the
  business layer need to be logged, and the
  messages sanitized before being propagated to the
  caller

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Exception Handling App Block cont.

• 3 Handler Types Available
• Wrapping - wraps one exception around another
• Replace - replaces one exception with another
• Logging - formats exception info and log with
  Logging App Block
• if (ExceptionPolicy.HandleException(ex, "Data
  Layer Exception Policy"))
• throw

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Need Cryptography Application Block?Is your team

• Writing the same code over and over for the
  plumbing around cryptography (streams,
  initialization vectors, strings to byte array
  conversions, etc.)
• Fretting over which algorithm to use in your
  application code, knowing that changing
  algorithms will force application code changes
• Wrestling with how to manage cryptography keys

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Cryptography Application Block cont.

• Provides a simplified approach to implementing
  common cryptography scenarios
• Includes modules for symmetric cryptography and
  hashing
• Each module supports pluggable algorithms and key
  stores
• Supports all .NET crypto algorithms out of the
  box, or developers can implement their own
• Algorithms and keys can be managed through the
  configuration tool

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Caching Application Block

• Provides a flexible and extensible caching
  mechanism that can be used at all layers of an
  application
• Supports backing stores that persist cache data
  into a database or isolated storage, so the data
  can survive app restarts
• Use in WinForms, Services etc for ASP.Net cache
  like functionality
• For ASP.Net, use if ASP.Net cache does not suffice

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Caching Application Block cont.

• Time-based and Notification-based expiration
• Absolute or Sliding time-based expiration
• CacheManager productsCache CacheFactory.GetCache
  Manager()
• Product product (Product) productsCache.GetData(
  productID)
• if (product null)
• // Retrieve it from the data provider
• // and cache it for more requests.
• product dataProvider.GetProductByID(productI
  D)
• if (product ! null)
• productsCache.Add(productID, product)

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Security Application Block

• Provides a simple API and pluggable
  implementations of core security primitive
  operations
• Covers 5 security areas Authentication,
  Authorization, Roles, Profile and Security
  Caching
• Each module supports extensible plug-in
  providers. In general we supply plug-ins for
  common Microsoft infrastructure (AD, AzMan) as
  well as a light-weight database implementation
• Developers can build their own plug-ins to
  interface with existing security solutions

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Learning More

• Patterns and Practices - http//msdn.microsoft.com
  /practices/
• Workspace Home (download location)
  http//workspaces.gotdotnet.com/entlib
• WebCasts http//www.pnplive.com
• Community extensions and custom blocks at the
  gotdotnet site

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Questions?

• John Viner
• John_at_softteq.com
• www.softteq.com
• http//community.softteq.com/blogs/john