Transcript Business value with Silverlight

Business value with Silverlight
READING, WRITING, BINDING, VALIDATING
AND VISUALISING YOUR DATA
Introductions
 Me
 I work at Datacom, on a large range of projects, primarily user interfaces
 I have been yearning to try Silverlight but haven’t had the chance at work
 My blog is at www.robfe.com. It’s a bit... new?
 You
 Who’s done
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Silverlight
Flash
Wpf
Astoria
ASP MVC
REST
LINQ to Entities
LINQ
C#
The Agenda
 Foundation
 XAML
 DependencyObjects and DependencyProperties
 Templates, Styles & Resources
 Layout
 Working with Data
 Access (with Web Services & REST)
 Binding
 Validation
 Visualisation
Business Value?
Foundations of Silverlight: XAML
 What is a Silverlight App?
 A parallel universe of dlls
 System.Windows.Controls
classes arranged together
(usually via XAML)
Web Page
Silverlight
host
 XAML - a format for
building objects via XML
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WPF, Silverlight, WWF etc
Application
(App.xaml)
 Why would you bother
with XAML?
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Designer support
Designer support
UserControl
(Page.xaml)
FoS: Dependency Properties
 Silverlight objects are
DependencyObjects
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DependencyObjects have
DependencyProperties
 Child objects can
“inherit” properties from
their parents
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Great for layout
Actually, you can set any
DependencyProperty on
any DependencyObject
(but there might be no
point)
FoS: Styles and Templates
 Styles can be used to
“set” values on existing
object trees
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A bit like CSS
Bindings only work in
WPF
 Templates can replace
the object tree itself
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ListView is the most
common place to do this
We’ll go into this...
FoS: Layout and Animations
 Layout
 It’s got some sweet layout controls
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Grid, Canvas, StackPanel
No more cross browser issues
 Animations
 It’s got some sweet animation support.
 In XAML you declare the start and end values of properties
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Easing
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Colours, Positions, Opacities, Sizes
Makes things look “natural”
Subtle animations are good for business
Business Scenarios for Silverlight
 90% of what we do has a
central data store
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Silverlight has to get its
data over http (no
database connection)
 Silverlight > ASPX etc
 Stateful
 Easy to bind
 Validation can be very
user friendly
 You can make it look
totally hot.
 Rich visualisations
Back end
Database
Business Logic
Domain model
Web Server
Host Page
Web Service for
Data
REST?
Silverlight client
Data binding
Validation
Visualisation
User
Armed with key
data
Leverages
synergies
Pays you
money
Data Access
 Web Services
 REST
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SQL Server Data Services
AKA Astoria
See Diagram
 Sockets (push data)
 All data operations are
asynchronous
(BeginBlah, EndBlah)
 DEMO
Database
LINQ to Entities model
DataService
Http
DataServiceContext(Client)
Data Binding
 Databinding in Silverlight is very good
 Hierarchy Navigation
 DataContext inheritance
 Two Way
 XAML:
<TextBox x:Name="txt1" Text="{Binding 'Name', Mode=TwoWay}"/>
 Code:
txt1.SetBinding(TextBox.TextProperty,
new Binding("Name"){Mode=BindingMode.TwoWay});
 DEMO
Data Validation
 The BindingValidationError event bubbles up
 Bindings support single property validation:
 ValidatesOnExceptions: Cause a validation error instead of
throwing the exception
 NotifyOnValidationError: Raise the BindingValidationError
event if there is a binding error
 We can throw exceptions from within our property
setters.
 DEMO
Data Visualisation
 Visual Properties can be databound
 Canvas.Left, Grid.Row etc
 The visual elements in SL/WPF are really easy to
work with
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Great layout options
All visual elements are objects (no more DrawRectangle())
Templates also provide a lot of power
 DEMO
Tips, Tricks, Workarounds
 Astoria Client
 Cast your IEnumerable<T> queries into DataServiceQuery<T>
to get access to Expand and BeginExecute
 When saving related records / foreign keys, you have to
manually call AddLink on your context
 Astoria Service
 Set config.UseVerboseErrors=true while debugging to get
error messages out of your svc
 Test it with Firebug/Fiddler/Charles
 config.SetEntitySetAccessRule("*", EntitySetRights.All);
Tips, Tricks, Workarounds continued
 Expression Blend
 Loads of draggy droppy support for templates, bindings, styles,
gradients & paths. All the stuff you don’t want to hand code.
 You can give a user control a “Design time size”
 You have to reference a different DLL to get more controls
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Don’t try and use DatePickerTextBox
 Silverlight
 Sometimes your browser will cache your XAP – delete temp
files if you don’t see your changes reflected
 Really good JavaScript bridge
 If you’re accessing services not on your domain, make sure you
read up on cross domain JavaScript.
Thank you
 Questions?
 Feature Requests?
 Slides & Solution will be on my blog: www.robfe.com
 All comments, questions, donations totally
appreciated: [email protected]