Author: Dottie

Onward with our multi-component Project!

Last week we decided on an overall purpose for our project. We will create a Web service and several different Clients to consume the service. Today, we will break into our teams to work on development of these components.

• Review discuss overall project plan: role of Web Service and what each client component will do
• Goals: set up your development environment; decide on pairs to work together on the coding; use a tutorial to develop a sample to familiarize yourselves with the use of the IDE (Integrated Development Environment) and learn a bit about the language

Web Service Team:

• Get started developing the Web Service in C# using Visual Studio 2017 Community Edition
• Visual Studio Community Edition 2017  free versions for Windows or MacOS
• This is a nice tutorial for getting started with a sample Web Service and has versions for Mac and for Windows: Create a Web API Windows version  Create a Web API MacOS version
• We will only be using the GET Request for our project, so you can focus on that when going through the above tutorial
• Look at the sample POC (Proof of Concept) code from Robin’s GitHub for a Web Service calling the existing Weather Service and for the console app that calls the new Web Service. See the Web Services channel in Slack
• Decide on what the REQUEST from the Client needs to look like and what your Web Service RESPONSE will look like. What is the JSON object structure?

Swift IOS Team:

• Get started developing an app in XCODE using the Swift programming language that will consume the Web Service, i.e. send it a REQUEST and process the RESPONSE
• XCode: Install XCode version 9 from the App Store; it may also require you to update your operating system. This can be a very slow process as we saw last week, so if your machine isn’t set up yet, we will just share the Macs that are ready and get the others started with the installation.
• Get Sample Chapters of Book: Coding iPhone Apps for Kids: This is a very nice book for learning Swift. Try the free sample chapters! You can get the free sample from Amazon (Chapter 1 and part of Chapter 2) and you can get Chapter 3 for free from the Book’s Web Site at NoStarch Press:
• Create a simple Hello World project to get familiar with the IDE; we can use the example in Chapter 1 of the book for this
• Run your sample code on your phone!: Attach your iPhone or iPad to your development Mac using the USB cable while running your project in XCode. Chapter 1 of the book explains how to do this. One additional thing that may crop up that is not in the book is that you may get a message like this when you try to run the app “Codesign wants to access key ‘access’ in your keychain”. If this appears, you need to enter your Mac login id (not your Apple id).
• For more practice and help using the XCode IDE and Swift, Apple has a good Swift Tutorial from Apple Developer Site
• Design your UI (User Interface): decide what types of “widgets” should be on the screen. Should there be more than 1 screen?
• Start building the initial iteration of the UI by adding elements to the story board

Other Teams?:

• Last week we also discussed building additional Clients, including:
  • Web Page with JavaScript to call the Web Service
  • AppInventor: Web-based IDE with coding blocks for Android devices
  • C# Console Application: simple application build in Visual Studio to call the Web Service and display a result
• If anyone wants to work on one of those teams we will help you get  started. Or we can circle back to those in a couple of weeks….

Web Service Overview: 

In Client/Server architecture, the Web Service is the Server and the Clients can be one or more applications(Web sites, mobile app, console app, etc.) that send an HTTP REQUEST to the Web Service and receive an HTTP RESPONSE back from the Web Server. The Web Service provides an API (Application Programming Interface to receive the REQUESTS from a Client. The Client software must know the specifications for formatting and submitting the REQUEST. The Client software must parse the RESPONSE from the API call to get the data into a format that the Client can use. Our Web Service will return the data in JSON (JavaScript Object Notation).

More Resources:

Check out this tutorial for more on JSON: W3C Schools JSON

Sample Code for various types of Clients calling the Weather Underground Service: Wunderground API Call Samples

Visual Studio C# Example of a Web API Client: Calling a Web API from a .NET Client

This evening we will meet back at our usual time and place: 25N Coworking at 5:45 PM.

Agenda:

Guest Speaker: Grace Haaf. Grace earned a PhD from Carnegie Mellon, has done extensive work in engineering and big data as well as owning her own company and recently participating in the Democratic primary process for the IL 6th Congressional District. We are looking forward to hearing her perspective on working in tech while being an active and engaged citizen in the political process.

Techie Table Talk:  Following Grace’s presentation, we’ll hang out around our Conference Table where our FVGCC Members can share thoughts on what we just heard or discuss other ideas and interests related to tech fields, women in tech, educational opportunities, projects we may work on, upcoming events, etc.

Slither Onward with Game Development — It’s time for the Snake Game!

• Let’s Play! Fire up the code in our Chapter 6 code directory in Cloud 9 and try out the game to get a feel for how it works
• Makey Makey: Add a Makey Makey input device and get creative on how to connect to the game!
• Get a glimpse of Object-Oriented coding:  We will take a brief look at how the game uses the concept of a class and an object that represents an instance of that class. 
  • Classes and Objects are the most important concepts in Object-oriented languages like C++, C#, and Java.

Class: a template representing some type; it has properties that hold values representing state and methods (aka functions) that invoke behaviors. Example: we can define a class Snake that has properties for size, body, skin, isAlive, and more. The properties may be given initial values within the class definition

But does JavaScript have real classes?: JavaScript didn’t have an actual “class” keyword and syntax until a 2015 specification which may not be implemented yet by all Browsers; see this MDN article on JavaScript classes

Constructor Function declaration conceptually implements a class: In the Snake program (written prior to the 2015 addition of “class” to JavaScript),  the Snake variable defined by a constructor function is conceptually a class

Constructor: a function used to create a new instance of the class; it may have parameters which are values passed to the function and used to set some initial values for the object. The Snake constructor starts like:

 var Snake = function(x, y, width, height, maxSize) {

Object: an instance of a class that can have its properties set and its methods invoked in code. For example, we create a Snake instance like this:   var snake = new Snake(0, 0, canvas.width, canvas.height, 1000);