Xamarin Workshop Noob to Master – Week 5
- 1. XAMARIN FORMS NOOB TO MASTER By Rendy Del Rosario and Charlin Agramonte Week 5
- 2. Objectives - Understand what is a Web service - Understand what is a REST API and how to use in Xamarin - Consume a real API in Xamarin
- 3. Web Service A web service is a collection of open protocols and standards used for exchanging data between applications or systems. For transferring data it uses: - XML - JSON SOAP RESTFUL TYPES
- 4. API (Application Programming Interface) Is a set of defined functions and methods for interfacing with the underlying operating system or another program or service running on the computer.
- 6. What are REST services? REST (Representational State Transfer) is an architecture for creating distributed applications which is modeled around the HTTP specification
- 7. Definition URL HTTP methods A media type for the data https://www.some_address.com/customers GET/POST/PUT/PATCH/DELETE JSON/ XML
- 8. Rest operations - Get - Post - Put - Patch - Delete
- 9. Rest operations: GET This operation is used to retrieve data from the web service. https://www.some_address.com/users/ https://www.some_address.com/users/5 https://www.some_address.com/users?id=5
- 10. Rest operations: POST This operation is used to create a new item of data on the web service. https://www.some_address.com/users/5
- 11. Rest operations: PUT This operation is used to update an item of data on the web service. https://www.some_address.com/users/5
- 12. Rest operations: PATCH This operation is used to update an item of data on the web service by describing a set of instructions about how the item should be modified. https://www.some_address.com/users/5
- 13. Rest operations: DELETE This operation is used to delete an item of data on the web service. https://www.some_address.com/users/5
- 14. Media Types
- 15. JSON JSON (JavaScript Object Notation) is a lightweight format that is used for data interchanging. It is based on a subset of JavaScript language (the way objects are built in JavaScript).
- 16. HttpStatus The REST service sends an HTTP status code in the HttpResponseMessage.StatusCode property, to indicate whether the HTTP request succeeded or failed. The common responses for this operation are: 201 (CREATED) 400 (BAD REQUEST) 500 (SERVER ERROR) 404 (NOT FOUND)
- 17. Example
- 18. Security in REST - Security is ultimately decided by the service – the client can only conform to what the service allows - Should always prefer https to protect the data peer-to-peer
- 19. REST in Xamarin
- 20. Xamarin API Options HttpClient ServiceStack RestSharp Platform Specific Most common approach, built into .NET Full fledged 3rd party web services framework, has client PCL for consuming REST services Full 3rd party client library that supports file downloads, authentication, chunking, etc Native Platform Apis for networking calls
- 21. HttpClient The HttpClient class is used to send and receive requests over HTTP. It provides functionality for sending HTTP requests and receiving HTTP responses from a URI identified resource. Each request is sent as an asynchronous operation.
- 22. HttpClient - Get JsonConvert is a Json.NET class that can serialize and deserialize data from a JSON string or stream based on a specified Type
- 24. HttpClient - Post/Put/Delete Must serialize body and include encoding and content type
- 26. Let’s do it step by step 1-Create an Interface IApiService for your call definitions 2-Create a class ApiService to handle your requests and implement the previously created interface 3-Implement your request calls in your Api Service and define them in your Interface 4-Do your calls in your ViewModel 5-Show the data in your views
- 27. GROUP EXERCISE Interact with our first API
- 28. INDIVIDUAL EXERCISE Using the Public API Create an app for get a RNC of a company TIME: 45 MINUTES
- 29. IOS - NSAppTransportSecurity App Transport Security (ATS) enforces secure connections between internet resources (such as the app's back-end server) and your app.
- 30. Mobile Networks Applications should always determine whether a network is available before starting a network operation
- 31. INDIVIDUAL EXERCISE Add connectivity handler to your actual project TIME: 15 MINUTES
- 32. Refit Refit is a library heavily inspired by Square's Retrofit library, and it turns your REST API into a live interface https://github.com/paulcbetts/refit
- 33. Helpful tools for Json and Request Handlers - http://json2csharp.com/ - https://www.getpostman.com/docs/postman/launching_postman/navi gating_postman
- 34. HOMEWORK PRACTICE Using the Public API for Weather Create an App to get the Weather of Santo Domingo, DR
- 35. Recommended Lectures - Web Service https://developer.xamarin.com/guides/xamarin-forms/cloud-services/consuming/ - HttpClient in Xamarin Forms http://blog.xhackers.co/httpclient-with-xamarin-forms/ https://www.youtube.com/watch?v=xNP-K37mssA
- 36. By Rendy Del Rosario and Charlin Agramonte Week 5 THANK YOU!!!