MvvmCross Introduction
- 1. MvvmCross Introduction 13th December 2012 @slodge
- 2. Presentation Model Represent the state and behavior of the presentation independently of the GUI controls used in the interface. http://martinfowler.com/eaaDev/PresentationModel.html
- 3. In 2005… Model/View/ViewModel is a variation of Model/View/Controller that is tailored for modern UI development platforms where the View is the responsibility of a designer rather than a classic developer. Tales from the Smart Client, John Grossman http://blogs.msdn.com/b/johngossman/archive/2005/10/08/478683.aspx
- 4. Also in 2005… • 10 years of dev – C++, C, VB, Java, JavaScript, LISP, SmallTalk, Delphi, … • A year off travelling – from Argentina to Zambia • DeveloperDeveloperDeveloper • 1 conclusion:
- 5. MvvmCross Introduction Evolving the dinosaur 13th December 2012 @slodge
- 6. What we’ll cover… • MVVM Theory • .Net MVVM • A practical example – some code! • Interface Driven Development – Portable Class Libraries – Unit Testing – Plugins • Some examples
- 7. What we’ll cover… • MVVM Theory • .Net MVVM • A practical example – some code! • Interface Driven Development – Portable Class Libraries – Unit Testing – Plugins • Some examples
- 8. M-V-VM
- 10. What we’ll cover… • MVVM Theory • .Net MVVM • A practical example – some code! • Interface Driven Development – Portable Class Libraries – Unit Testing – Plugins • Some examples
- 11. ViewModels Public Properties private bool _isSearching; public bool IsSearching { get { return _isSearching; } set { _isSearching = value; RaisePropertyChanged("IsSearching"); } }
- 12. For ViewModel Changes public interface INotifyPropertyChanged { event PropertyChangedEventHandler PropertyChanged; } public class PropertyChangedEventArgs : EventArgs { public string PropertyName { get; } }
- 13. For Collections public interface INotifyCollectionChanged { event NotifyCollectionChangedEventHandler CollectionChanged; } public enum NotifyCollectionChangedAction { Add, Remove, Replace, Move, Reset, } public class NotifyCollectionChangedEventArgs : EventArg { public NotifyCollectionChangedAction Action { get; } public IList NewItems { get; } public IList OldItems { get; } public int NewStartingIndex { get; } public int OldStartingIndex { get; } }
- 14. For Actions public interface ICommand { event EventHandler CanExecuteChanged; bool CanExecute(object parameter); void Execute(object parameter); }
- 15. .Net Implementation ICommand Public Property Set INotifyPropertyChanged INotifyCollectionChanged Public Property Get
- 16. Why? To Enable • Awesome UI and Data Development • Unit Testing of code • Large applications to have a common architecture • Different platforms can share code
- 17. What we’ll cover… • MVVM Theory • .Net MVVM • A practical example – some code! • Interface Driven Development – Portable Class Libraries – Unit Testing – Plugins • Some examples
- 18. What is MvvmCross? Code!
- 19. Code evolution I • Single Mono for Android Project • Good separation of UI from ‘Model’ code • Simple – it works • But: – No testing – No testability – Portability by cut/paste
- 20. Code Evolution 2 • MvvmCross Library switched in – PCL code – Formal DI/IoC used • On UI: – DataBinding arrived – Code got much thinner! – XML got bigger • Not all win: – External Dependencies got larger – Code overall increased in size
- 21. Code Evolution 3 • Cross Platform • All UIs MVVM • 100% shared application logic • 100% shared test harness
- 22. Data-Binding WP/WinRT 99% Xaml Droid Mainly Axml Some .Dialog Touch Some .Dialog Some .XIB Some C#
- 23. What we’ll cover… • MVVM Theory • .Net MVVM • A practical example – some code! • Interface Driven Development – Portable Class Libraries – Unit Testing – Plugins • Some examples
- 25. Unit Testing “I get paid for code that works, not for tests, so my philosophy is to test as little as possible to reach a given level of confidence. … When coding on a team, I modify my strategy to carefully test code that we, collectively, tend to get wrong.” Kent Beck http://stackoverflow.com/questions/153234/how-deep-are-your-unit-tests
- 26. Plugin – Native abstractions 1. Declare common functionality (an interface) public interface IMvxComposeEmailTask { void ComposeEmail(string to, string cc, string subject, string body, bool isHtml); } 2. Write platform specific implementations public class MvxComposeEmailTask : MvxWindowsPhoneTask, IMvxComposeEmailTask { public void ComposeEmail(string to, string cc, string subject, string body, bool isHtml) { var task = new EmailComposeTask() { To = to, Subject = subject, Cc = cc, Body = body }; DoWithInvalidOperationProtection(task.Show); } } 3. In apps, use the interface and not the implementation protected void ComposeEmail(string to, string subject, string body) { Cirrious.MvvmCross.Plugins.Email.PluginLoader.Instance.EnsureLoaded(); var task = this.GetService<IMvxComposeEmailTask>(); task.ComposeEmail(to, null, subject, body, false); }
- 27. Sphero – Plugin Magic • Plugin Magic • Each Plugin: – 1 PCL – 1 Assembly per platform
- 28. Why? To Enable • Awesome UI and Data Development • Unit Testing of code • Large applications to have a common architecture • Different platforms can share code
- 29. What we’ll cover… • MVVM Theory • .Net MVVM • A practical example – some code! • Interface Driven Development – Portable Class Libraries – Unit Testing – Plugins • Some examples
- 30. MonoCross
- 31. A team in a galaxy far far away @imaji @mrlacey @sichy @slodge @touch4apps …
- 42. What we’ve covered… • MVVM Theory • .Net MVVM • A practical example – some code! • Interface Driven Development – Portable Class Libraries – Unit Testing – Plugins • Some examples
- 43. To join in… If you want to join in: • Tool up • Share • Reuse • Test • Architect
- 45. Some other talks available http://bit.ly/mvxTweetPic
- 46. C# - 1 Stack - Cloud to Mobile Data Access Business Logic Presentation Service Consumption Local Data/Services Business Logic UI Logic WP7 iOS Droid Win8
- 47. Not as cool as dinosaurs Data Access Business Logic Presentation Service Consumption Local Data/Services Business Logic UI Logic WP7 iOS Droid Win8
- 48. Some credits Images from Wikipedia Commons: • http://en.wikipedia.org/wiki/File:Macronaria_scrubbed_enh.jpg • http://en.wikipedia.org/wiki/File:Human- eoraptor_size_comparison%28v2%29.png Diagrams from Java – ZK • http://books.zkoss.org/wiki/ZK_Developer%27s_Reference/MVVM Sample projects as credited inline
- 49. Thanks for listening… http://cirrious.com http://slodge.blogspot.com http://github.com/slodge/mvvmcross me@slodge.com @slodge Stuart Lodge, I’m a Dinosaur
- 50. Xamarin Seminar Please give us your feedback http://bit.ly/xamfeedback Follow us on Twitter @XamarinHQ 13th December 2012