ASP.NET 2.0 Caching and Data Binding

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ASP.NET 2.0 Caching and Data Binding

• Josh Holmes

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About Josh Holmes

• Consultant/Trainer/Mentor
• Principal in SRT Solutions
• Great Lakes Area .NET Users Group
• Vice President
• Program Chair
• Ann Arbor Computer Society
• President
• INETA Speaker
• Microsoft MVP
• http//www.srtsolutions.com
• jholmes_at_srtsolutions.com

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About International .NET Association (INETA)

• http//www.ineta.org
• Mission
• To offer assistance and resources to community
  groups that promote and educate their membership
  in Microsoft's .NET technologies
• Organizational For user group leaders and
  officers
• Helping groups get organized for a more
  sustainable group
• Educational Supporting the core need of user
  groups
• Presentation repository with content from both
  sponsor companies and other user groups
• Speakers Bureau will provide groups with
  opportunities to attract marquee speakers and
  noted .NET authors from around the country
• Promotional Building the membership
• Searchable, international user group directory
• Promote user groups at major .NET events

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Agenda

• What is Data Binding?
• What are the new Data Binding features in ASP.NET
  2.0?
• What is Cache?
• What are the Caching features in ASP.NET 2.0?
• How to leverage the two together...

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What is Data Binding?

• Using Data Bound controls to generate the HTML
  rather than writing the HTML yourself
• Everything from Calendar to TextBoxes can be data
  bound
• Major Data bound controls
• DataGrid (ASP.NET 1.0/1.1)
• GridView (ASP.NET 2.0)
• DetailsView (ASP.NET 2.0

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ASP.NET 1.1 Databinding

• Steps to data binding
• Pull data
• Create the data bound controls
• Assign the Data Source to the newly pulled data
  (often a dataset, but could be an object)
• Use Property Pane and/or ASP.NET 1.1 data binding
  syntax to pull property

lt DataBinder.Eval(Container.DataItem,
"PropertyName") gt
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ASP.NET 2.0 Binding

• Steps to data binding
• Pick a data source
• Pick display format
• Drag data source onto form
• Possibly use ASP.NET 2.0 data binding syntax to
  edit
• More on next slide

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ASP.NET 2.0 Binding cont.

• Old form still works
• Two new forms
• Nonhierarchical data binding
• Hierarchical (I.E. XML)

lt Eval("PropertyName") gt
lt XPath(XPath Statement") gt
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New GridView Control

• Similar to DataGrid
• Sorts and pages with no code
• Also sizes for phones and other devices with no
  extra code
• Can have no code data editing
• Using two way bindings
• Bind instead of Eval

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More new controls

• Details View
• Mostly for use with a GridView
• Provides detail view for one of the master rows
  in a sub-grid
• Form View
• Similar to the previous control except that it is
  all templated rather than a grid style layout
• Similar to the Data Repeater from 1.x

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Data Source Controls

• Replaces majority of data access code written in
  ASP.NET 1.x
• SqlDataSource
• AccessDataSource
• DataSetDataSource
• XmlDataSource
• Can select data, specify how to edit data and more

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What is Cache?

• Per Application on a Machine store of memory
• Two kinds Data Cache and Page Cache
• Data Cache allows caching of any .NET object
• Often used to limit trips to database but still
  give dynamic look and feel to web site
• Page Cache allows caching of an ASPX or ASCX
• Used to produce high performance but seldom
  changing pages

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Page Caching

• Caches the rendered output
• Savings
• Processing time
• Data access time
• Can be set up administratively after the app is
  deployed
• Can be used on just a user control
• Can be parameterized

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How to Page Cache

• Page caching is administered through the
  OutputCache directive in the page
• Next to PageDirective

lt_at_ OutputCache Duration"ofseconds"
Location"Any Client Downstream Server
None" Shared"True False" VaryByControl"contr
olname" VaryByCustom"browser customstring"
VaryByHeader"headers" VaryByParam"parameternam
e" gt
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Data Caching

• Compare to Application storage
• Not cross machine
• Much better in many situations with cache
  invalidation and timeouts
• Caches any .NET object
• Does not save rendered HTML
• Savings
• Data access time
• Often used to cache datasets

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How to Data Cache

• Insert an object into the Cache object
• Stored in memory on this machine/application
• Stored until server sees fit to remove it or
  restart of application

string t Cache"TimeString" as string if (t
null) t DateTime.Now.ToString()
Cache.Insert("TimeString", t) _lblTime.Text
t
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How to Data Cache Cont

• Adding Timeouts
• Set the TimeSpan to Zero and the timeout to an
  absolute time
• Set the absolute time to MaxValue and the
  TimeSpan to some number of seconds
• Adding Dependency
• One Type in v1.1 and its a File Dependency

CacheDependency d new CacheDependency(_at_"c\test.
xml") Cache.Insert("TimeString", t, d,
DateTime.MaxValue, TimeSpan.FromSeconds(10),)
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Data Cache Removal Callbacks

• Receive a delegate callback when an object is
  removed from cache

public void RemovedCallback(string key, object o,
CacheItemRemovedReason reason) //Do nothing
at the moment
Cache.Insert("TimeString", t, d,
DateTime.MaxValue, TimeSpan.FromSeconds(10),
System.Web.Caching.CacheItemPriority.Normal,
new CacheItemRemovedCallback(this.RemovedCallbac
k))
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V2.0 Caching Features

• Single biggest is that CacheDependency is not
  sealed
• Can create custom dependencies or use
  SQLCacheDependency

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Why is it important?

• Imagine Cache Dependencies on
• MSMQ
• RSS
• A web service
• Active Directory

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SQL Cache Dependency

• 3 things have to be setup
• SQL Server
• Run utility or wait for SQL Server 2005
• Application
• Web.Config
• Your Code
• Could be declaratively through the OutputCache
  directive
• Could be in code

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SQL Cache Dependency Config
ltcachinggt ltsqlCacheDependency enabled"true"
pollTime"1000"gt ltdatabasesgt ltadd
name"Northwind connectionStringName"NorthwindC
onnectionString1"/gt lt/databasesgt lt/sqlCacheDepe
ndencygt lt/cachinggt
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ASPNET_REGSQL utility

• -S server
• -E trusted connection
• Could use U and P for user and password
• -t table to enable for notification
• -d database
• -et enable triggers

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Output Cache Replacements

• Allows substitution of one small area in the
  prerendered HTML output
• Use an aspsubstitution
• Provide a method for the call back

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ASP.NET 2.0 Caching and DataBinding

• Josh Holmes