MvvmCross is moving to a portable class library architecture to address problems with the previous version. The new version separates platform-specific code from portable code to reduce library size and enable automated cross-platform refactoring. Core functionality like MVVM patterns and a plugin system are defined in portable class libraries. Platform-specific implementations provide interfaces for each plugin. This allows plugins to be written once and used across platforms, improving extensibility and simplifying support for new platforms.

1. MvvmCross – Going Portable
Going Portable
@slodge

2. MvvmCross
Version 1

3. MvvmCross MvvmCross MvvmCross MvvmCross
.WP7 .Touch .Droid .WinRT
MyApplication MyApplication MyApplication MyApplication
.WP7 .Touch .Droid .WinRT
MyUI MyUI MyUI MyUI
.WP7 .Touch .Droid .WinRT
MvvmBinding MvvmBinding
.Touch .Droid

4. MvvmCross MvvmCross MvvmCross MvvmCross
.WP7 .Touch .Droid .WinRT
Core MvvmCross MyApplication
MyApplication Library contains: MyApplication MyApplication
.WP7 .Touch .Droid .WinRT
• Mvvm interfaces and base classes
• Simple DI container and IoC controller
MyUI MyUI MyUI MyUI
• Platform specific navigation• and presentation logic
.WP7 .Touch M .Droid .WinRT
• Platform specific implementations of MvvmBinding
MvvmBinding
.Touch .Droid
file, location, camera, etc

5. MvvmCross MvvmCross • M MvvmCross MvvmCross
.WP7 .Touch .Droid .WinRT
MyApplication MyApplication MyApplication MyApplication
.WP7 .Touch .Droid .WinRT
MyApplication Library contains:
MyUI MyUI MyUI MyUI
.WP7 .Touch .Droid .WinRT
• Application startup logic
MvvmBinding
.Touch
MvvmBinding
.Droid
• Models and Services • M
• ViewModels
• ValueConverters
Identical code across platforms – just cut-and-paste projects

6. MyUI Executable contains:
MvvmCross MvvmCross MvvmCross MvvmCross
.WP7 .Touch .Droid .WinRT
• M
• Platform Specific Views and Controls
• Some adaption for ValueConverters
MyApplication MyApplication MyApplication MyApplication
.WP7 .Touch .Droid .WinRT
MyUI MyUI MyUI MyUI
.WP7 .Touch .Droid .WinRT
MvvmBinding MvvmBinding
.Touch .Droid

7. Problems
• MvvmCross is a “fat” library – contains more than just
mvvm!
• Compiled image sizes can be large – especially on
MonoTouch
• Application libraries are cut and paste – a boring, error
prone manual job
• Automated cross-platform refactoring is impossible
• No common way to extend the platform
• Each new platform added requires manual cut-and-
paste duplication of projects

8. MvvmCross
Version Next

9. MvvmCross
.Portable
MyApplication
.Portable
Plugin1 Plugin2
…
.Portable .Portable
MyUI MyUI MyUI MyUI
.WP7 .Touch .Droid .WinRT
MvvmCross MvvmCross MvvmCross MvvmCross
.Adapter.Wp7 .Adapter.Touch .Adapter.Droid .Adapter.WinRT
Plugin1 Plugin1 Plugin1 Plugin1
.Wp7 .Touch .Droid .WinRT
Plugin2 Plugin2 Plugin2 Plugin2
.Wp7 .Touch .Droid .WinRT
… … … …

10. MvvmCross
.Portable
MyApplication
MvvmCross is a single Portable library containing:
.Portable
Plugin1 Plugin2
…
.Portable .Portable
• Mvvm base classes
• Simple DI container and IoC controller
• Plugin Loader base interfaces
MyUI MyUI MyUI MyUI
.WP7 .Touch .Droid .WinRT
MvvmCross MvvmCross
• M MvvmCross MvvmCross
.Adapter.Wp7 .Adapter.Touch .Adapter.Droid .Adapter.WinRT
Plugin1 Plugin1 Plugin1 Plugin1
.Wp7 .Touch .Droid .WinRT
Plugin2 Plugin2 Plugin2 Plugin2
.Wp7 .Touch .Droid .WinRT
… … … …

11. MvvmCross
.Portable
MyApplication
.Portable
Plugin1 Plugin2
…
.Portable .Portable
MyUI MyUI MyUI MyUI
MyApplication is a single Portable library containing: .WinRT
.WP7 .Touch .Droid
MvvmCross MvvmCross MvvmCross MvvmCross
• Application startup logic
.Adapter.Wp7 .Adapter.Touch .Adapter.Droid .Adapter.WinRT
• Models and Services Plugin1 •
Plugin1
.Wp7 .Touch
M Plugin1
.Droid
Plugin1
.WinRT
• ViewModels
•
Plugin2 Plugin2 Plugin2 Plugin2
ValueConverters
.Wp7 .Touch .Droid .WinRT
… … … …

12. MvvmCross
.Portable
MyApplication
.Portable
Plugin1 Plugin2
…
.Portable .Portable
MyUI MyUI MyUI MyUI
The Portable part of each Plugin:
.WP7 .Touch .Droid .WinRT
MvvmCross MvvmCross MvvmCross MvvmCross
• Provides the interface for that plugin
.Adapter.Wp7 .Adapter.Touch .Adapter.Droid .Adapter.WinRT
• e.g. for Location it provides Start, Stop, and an
Plugin1
.Wp7
Plugin1 • M
.Touch
Plugin1
.Droid
Plugin1
.WinRT
OnLocationChanged event.
• Provides an EnsureLoaded() call for initialisation at runtime
Plugin2 Plugin2 Plugin2 Plugin2
.Wp7 .Touch .Droid .WinRT
… … … …

13. MvvmCross
.Portable
MyUI executable provides:
MyApplication
.Portable
• Platform Specific Views and Controls
• Some adaption for ValueConverters Plugin1
.Portable
Plugin2
.Portable
…
• M
MyUI MyUI MyUI MyUI
.WP7 .Touch .Droid .WinRT
MvvmCross MvvmCross MvvmCross MvvmCross
.Adapter.Wp7 .Adapter.Touch .Adapter.Droid .Adapter.WinRT
Plugin1 Plugin1 Plugin1 Plugin1
.Wp7 .Touch .Droid .WinRT
Plugin2 Plugin2 Plugin2 Plugin2
.Wp7 .Touch .Droid .WinRT
… … … …

14. MvvmCross
.Portable
The MvvmCross.Adapter for each platform provides:
MyApplication
.Portable
• Platform Specific Mvvm Helpers – e.g. binding Plugin2
Plugin1
• Platform Specific View and navigation
…
.Portable .Portable
• M
• Platform Specific Plugin Manager/Loader
MyUI MyUI MyUI MyUI
.WP7 .Touch .Droid .WinRT
MvvmCross MvvmCross MvvmCross MvvmCross
.Adapter.Wp7 .Adapter.Touch .Adapter.Droid .Adapter.WinRT
Plugin1 Plugin1 Plugin1 Plugin1
.Wp7 .Touch .Droid .WinRT
Plugin2 Plugin2 Plugin2 Plugin2
.Wp7 .Touch .Droid .WinRT
… … … …

15. Plugin Implementations: MvvmCross
.Portable
• Provide platform specific implementations of each Plugin
Interface MyApplication
• e.g. for Location a platform specific service will provide
.Portable
Start, Stop, and OnLocationChanged. Plugin1
.Portable
Plugin2
.Portable
…
• Are initialised at runtime using a mixture of:
• M
• Project references
MyUI
• Convention-based dynamic assembly loading MyUI
MyUI MyUI
.WP7 .Touch .Droid .WinRT
• Setup Helpers on platforms that don’t support
MvvmCross MvvmCross MvvmCross MvvmCross
Assembly.Load()
.Adapter.Wp7 .Adapter.Touch .Adapter.Droid .Adapter.WinRT
Plugin1 Plugin1 Plugin1 Plugin1
.Wp7 .Touch .Droid .WinRT
Plugin2 Plugin2 Plugin2 Plugin2
.Wp7 .Touch .Droid .WinRT
… … … …

16. Plugins – Portable Interfaces
In the Portable Library – Plugins.Email.dll:
public interface IMvxComposeEmailTask
{
void ComposeEmail(string to, string cc, string subject, string body, bool isHtml);
}
public class PluginLoader
: IMvxPluginLoader
, IMvxServiceConsumer<IMvxPluginManager>
{
public static readonly PluginLoader Instance = new PluginLoader();
#region Implementation of IMvxPluginLoader
public void EnsureLoaded()
{
var manager = this.GetService<IMvxPluginManager>();
manager.EnsureLoaded<PluginLoader>();
}
#endregion
}

17. Plugins – Portable Use
The plugin can be used in a Portable ViewModel as simply as:
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);
}

18. Plugins – Platform Specific
Implementations
In one platform specific implementation – Plugins.Email.WindowsPhone.dll:
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);
}
}
public class Plugin
: IMvxPlugin
, IMvxServiceProducer<IMvxComposeEmailTask>
{
#region Implementation of IMvxPlugin
public void Load()
{
this.RegisterServiceType<IMvxComposeEmailTask, MvxComposeEmailTask>();
}
#endregion
}

19. Advantages
• Core MvvmCross is now a much smaller library
• Compiled image sizes can be much smaller – especially
on MonoTouch
• Each Application is now a single library
• Cross-platform refactoring now a reality
• Manual cut-and-paste between projects eliminated
• Plugin technique allows easy extensibility for everyone
• New portable architecture makes it easier to add ans
support new platforms –
Silverlight, WPF, MonoMac, PlayStationSuite, …

20. Progress…
Working now: In progress:
• WP7 • MonoTouch
• Mono for Android
• WinRT