john sotiropoulos chief architect, metastorm – part of opentext @metastorm [email protected]...
TRANSCRIPT
John SotiropoulosChief Architect, Metastorm – part of OpenText
@metastorm
http://www.processmatters.com
MVVM In Real Life Partner logo to
go here
MVVM often raises temperatures, causes high spirited debates, and can lead to ruined pub lunches.
Looking at how and why is being used in commercial enterprise
applications may provide a useful insight.
Who is Metastorm?
• A leader in Enterprise Architecture (EA), Business Process Analysis (BPA) and Business Process Management (BPM).
• Brings people, technology, and processes together in order to solve specific problems and connect strategy to execution.
• Recently acquired by leading Content Management vendor OpenText.
Enterprise ArchitectureForrester Wave Q109
Business Process AnalysisForrester Wave Q109
IT PlanningForrester Wave Q109
Business Process Management Suites Forrester Wave Q310
Leaders in all process-related markets
Business Process Analysis Magic Quadrant Q110
Enterprise ArchitectureMagic Quadrant Q410
Business Process Management SuitesMagic Quadrant Q410
Selected Enterprise Customers
Partners
MVVM raised temperatures• Confining the MVVM
discussion to a “design pattern” led to conflicting views.
• But MVVM is not just another technique.
• MVVM liberates the design of User Experience to bring the user and developer together.
Design Patterns are important!
It’s too complex
No pub lunch with you
Why this extra work?
Where we used MVVM?The Silverlight-based Business Workspace, is a common framework for building all our end-user applications
Including our free Azure M3 modeling application.
http://m3.cloudapp.net/
M3/ Smart Business WorkspaceIntro Demo
Initial Development Workflows
User
DesignerDeveloper
Prototype & Develop
Design Mockups
Review Describe
Some early disconnectsMock up Implementation
…and pre-MVVM mock ups
Key Concerns
• Developers, and not UI Experts, were designing the UI.
• They were interpreting graphical mockups and it caused disconnects.
• We introduced Silverlight mockups which improved communication and reduced cycles but the interactivity was limited and it the design-abilty was often lost.
• Merging mock-ups caused integration defects and delayed user reviews and acceptance.
User Designer
Developer
Real / “Live” UI
and so we moved to this workflow
Widget UI (XAML View)ViewModel
ModelREST
Service
Initial MVVM Adoption • Only Notify Property Changed Implemented, e.g
public class GridViewModel : INotifyPropertyChanged{ private IList _rows = new ObservableCollection<object>(); private readonly Func<object> _createNewRow; public GridViewModel() { _createNewRow = () => new GridRowModel(null); AddGridRowCommand = new DelegateCommand<object>
(ExecuteAddGridRowCommand);}
Our MVVM Adoption Evolved• Moved towards re-use using base class that only wrapped
INotifyPropertyChange public class ViewModelLight : INotifyPropertyChanged, ICommandManager
{ public event PropertyChangedEventHandler PropertyChanged; …… }
• Then Expanded to a home-grown MVVMLight and an MVVM View Model Classpublic class ObservableObject : DependencyObject, INotifyPropertyChanged,
IDataErrorInfo {. Core object.} public abstract class ViewModel : ObservableObject, IViewModel {…}
• Learn from others and re-use: we are now looking to adopt MVVMLight
It was not all plain sailing…
• Steep learning curve / additional effort.
• Overkill for some simple cases where UI is not all that critical.
• Technical challenges in complex interactions (especially widget to widget events).
• Verbose duplication in data bindings and standard approaches in a large and distributed team– Homegrown equivalent to MVVMLight.
But we also noticed…• MVVM decoupled UI and facilitated agile responses to changes.
• UIs designed by the UI specialist topped, regularly, user acceptance.
• Using MVVM educated our market-eers and users to what is feasible and made them more educated on the controls available.
• MVVM-designed features were more stable and had more unit tests and automation tests.
Both M3 and the Smart Business Workspace were the highlight of our user conference and have received a great response from analysts and customers alike.
MVVM has been critical in making these products successful.
It forced a user-centric shift in our software development
Taking MVVM further
Dynamic MVVM
• We took MVVM a step further…
• Applied it to business processes to allow end-user mash up extensibility.
• Users can create their own data mash-ups, connected widgets, and interactive storyboards.
Data m
ashups(REST + O
DATA)
User Defined UI – Mock up of needs
Polished UI inBlend
Auto generated ViewModel
Model
DeploymentService
Dynamic MVVM overview
LWP / Dynamic MVVM Demo
Some lessons learned• Round tripping too complex for full UI round tripping.
• MVVM Requires Product UI Designer skills to get real value.
• ODATA and a centralized model management helps ViewModel generation.
• REST ODATA Services are easily accessible and help portability of the UI for the developer /designer round-trip.
• Eventing can become complex and needs a central event bus.
What we think now• The learning, investment, and challenges is worth it, if the UI is important.
• Re-Investing the gains in UI productivity in unit test and robust app logic is a good way to highlight the value of separating concerns.
• MVVM is a product development issue, not just a technical choice.
• Application Design-ability, is a trend that will move to other platforms, including HTML5
What’s cooking in our research labs• We are looking at using the separation of concerns in more specialised
Business Process Design and management and beyond Silverlight.• Using ODATA and jQuery for MVVM-like approach in HTML/HTML5.
Metastorm BPM Designer
Process-connected HTML
John SotiropoulosChief Architect, Metastorm – part of OpenText
@metastorm
http://www.processmatters.com
Partner logo to
go here
© 2008 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
Partner logo to
go here