How to Organise your Xamarin Solution by Adhering to

Common .NET Development Practices

Colombo Xamarin Meetuphttp://www.meetup.com/Colombo-Xamarin-Meetup/

About Me• Freelance Sitecore Consultant

• Sitecore MVP 2016

• Blog - http://sitecorefootsteps.blogspot.com

• YouTube - Sitecore for Dummies

• Initiator & Co-Founder - Sitecore User Group Sri Lanka

What We Going To Discuss

• Discuss a Simple Application to implement best practices

• How and why we implement Repository Pattern into the solution

• Dependency Injection

• Xamarin Forms Dependency Service

• Example application with Xamarin for Sitecore which uses Sitecore Mobile API

Simple Application• Home Screen

• Calculation Screen

• Two Input Fields

• On Calculate button clicked, Results Display

• Results keep in a Repository (memory in this case)

• When your return, you can see the last calculated result

What Can Be Improved ?

• UI and Logic Layer in one place

• Code maintenance is hard

• Hard to work in same functionality for two developers (ex: UI & Backend Devs)

• Hard to replace UI with new Technology

Improvement 1Moving Application Logic into a

Service Layer

• Easy to Maintain

• Easy for Backend and Front-end Developers to Work in Same Functionality

• Easy to Replace UI Layer

What Can Be Improved ?

• Data Storage is also Handled in Service Layer

• Hard to Change Storage Mechanism

• Service Layer implementation needs to wait till Full Storage functionality implemented

Improvement 2Moving Data Storage Functionality

Into Repository Layer

• Ease to Maintain

• Ease to Replace Storage Media

• Can Start Developing Functionality without Waiting for Storage Functionality

Repository Pattern

• Separates Data Access Layer from Logic Layer

• Retrieve data from data sources and convert them to Domain Objects, and pass them to Service Layer

What Can Be Improved ?

• One Layer is Dependent on Classes of Other Layer

• Tight Coupling

Improvement 3Dependency Injection

• Used to resolve dependencies

• DI Containers : Autofac, Ninject, StructureMap, Castle Windsor, etc

• In this example, we use Autofac 3.5.2

• Light-Weight

DependencyService

DependencyService• Allow to Register different implementation of an Interface for

each Target Platform• Framework uses correct implementation depending on the

platform• Need to place Dependency Attribute before the Class

Implementation

Disadvantages of DependencyService

• It is considered as Anti-Pattern• Adding a Dependency Attribute on Classes

tightly couples DI framework being used• Hard to write Unit Tests

Improvement 4Using DI to Replace DependencyService

Sitecore CMS

• One of the leading Content Management System in the world

• Provides a Mobile SDK for Xamarin

Simple App Calling

Sitecore Mobile SDK

• Sitecore Mobile SDK - a Portable .NET Library

• Provides an interface to work on Sitecore CMS

• Need to Implement your application methods as async calls

What We Did NOT Discussed

• MVVM Pattern

• Xamarin INotifyPropertyChange Interface

• Object-to-Object Mappers

Thank You!Source Code :

https://github.com/chaturangar/xamarin-footsteps