Month: February 2018

Meeting Announcements & Notes, Uncategorized

February 23, 2018 Meeting

Dottie

We will meet at our usual time and place: 5:45 PM at 25N Coworking

Finalize Plans for our Jellyvision Field trip!

Continue working on our multi-component Weather Wear software :

  • Review overall solution architecture: 

    • Lucid Chart diagram by Robin

WeatherWearArchitectureChart

  • C#/Swift Tutorial: Learn/review some object-oriented concepts

    • Classes and Objects: Properties (values) and Methods (behaviors defined in functions/procedures)
    • How are they defined and used in C#? In Swift?
    • Objects as Models for Data:

  • Web Service Team:

    • Merge Web API code with the GitHub Repo
    • Continue work on algorithm and implementation of the WeatherWear Web Service and the console app to test it

  • Swift Team:

    • MVC: Model/View/Controller design pattern
      • Model represents the data model defined in a class; we will create a model class for the Weather Forecast, and later for the WeatherWear API Response
      • View is the Presentation Layer, i.e, the screen the user sees
      • Controller: Code that handles the user input, talks to the model, handles interactions between Model and View. In Swift, we will define a Class for the controller; there will be a ViewController Class defined for each View
    • Review/Learn how to connect UI elements to code. Elements in the UI designed on the storyboard need to be connected to code in the appropriate controller:
      • @IBOutlet: in a code module, an Interface Builder Outlet is a variable that holds a reference to an element on the storyboard. Example:  our screen has a label to display a city name and we need our code to be able to access it. We add this to our view controller:

 @IBOutlet weak var cityLabel: UITextField!

      •  @IBAction: in a code module, an Interface Builder Action is a function that is connected to a user interaction with a UI element. Example: update the city label when the user clicks a button. We add a connection between the function named GetWeather and the button; then define the action inside the function

        @IBAction func GetWeather(_ sender: Any) { cityLabel.text = “Geneva”    }

    • Start setting up the code to send the Web API Request for WeatherWear
      • We will initially set up code to access the existing Weather Underground Forecast API
Uncategorized

February 9, 2018 Meeting

Dottie

This week we will continue working in our smaller teams developing the Web Service and the iOS app.

Web Service Team:

Last week the team completed the tutorial Create a Web API with ASP.Net Core MVC and Visual Studio for Mac or the equivalent version for Windows Create a Web API with ASP.Net Core MVC and Visual Studio for Windows

The team successfully completed the parts of the tutorial that got a Web Service running locally and allowed users to exercise GET requests

This week, we can use that foundation to add a new controller to the project to handle the GET request for our custom Weather Wear service that will return a JSON Response. The team can talk through design approaches and algorithms to decide what exactly the service should do and what additional components are needed. For example:

  • Should there be a Class library that will handle :
    • Sending a Request to the Wunderground API to get the weather?
    • Parsing the JSON results? How much of this is this needed here? Should the client of our API do some of this?
    • Logic to determine what our custom Response should add to the Response of the Weather Service
    • Define a Class that is a Model for our custom objects?
  • For the Controller for our Web API:
    • What parameters (if any?) should our GET Request(s) take?
    • Do we want more than one form of GET Request? Request by Zip Code? Request by City/State? Any others?? Decide on one for the initial iteration.
    • What Route name would we use? Attribute Routing in Web API
  • Take a look at Robin’s prototype code that includes a Web Service, a Class Library, and a Console App as Client

iOS Swift Team:

Last week, the team successfully completed the Hello World tutorial in the first chapter of the  book Coding iPhone Apps for Kids The link is to the book on Amazon where you can download the first Chapter as part of the free Sample. Following the tutorial, we were able to run the Hello World app on our iPhones/iPads attached via USB to the Macs running XCode. However, we did run into one problem with “provisioning” where an Apple ID used to sign the code was not getting successfully recognized as provisioned. Apple requires all Apps to be signed with a valid id in order to run on any attached device. It may just have been a slow lag time in having the credentials go through. We will take another look at it if still an issue. This is a forum that explains a bit about dealing with the issue: Forum discussion on iOS signing and provisioning issue

This week the team can work on developing the User Interface for the App using the Storyboard in XCode to add “views” to the screen. In XCode a View is an object on the screen (a more generic description would be a widget) . Some are controllers with which the user can interact (buttons, switches, text input boxes, etc.) and some are display only, such as labels. Design the view for the app, determining what is appropriate for input and display.

  • What will the Web Service need for us to send the Request? Will it be Zip Code, City/State?  Check with the Web Service team to find out their specifications for the Request. Provide the appropriate user experience for inputting the required information. Think about restricting the input to valid values. If a Zip Code is required, what can we do to make sure the user only enters digits and that it is in proper format? If we need a State is there a way to only allow selection of a valid state abbreviation?
  • When you get the results back from the Web Service API Request, how should it be displayed? What information do you want to display?
  • Do you want more than 1 screen? One for Request and one for Response? Or some other design
  • Add the appropriate views (widgets) for entering the Request and displaying the Response
  • We will take an initial look at how to hook up code to our UI:
    • Look at the ViewController.Swift class that is created automatically by the project
    • Add code in the ViewController that connects our “views” on the StoryBoard to the code; we will do this by control-dragging from the view to the code
      • @IBOutlet: Each outlet becomes a property in our ViewController class that is connected to a View (widget) on our screen. This allows us to use code to get or set the value as appropriate
      • @IBAction: This becomes a method of our ViewController class that is connected to an Action such as a Button is pressed, the screen is swiped, a gesture is made, text is entered, etc. We set up the connection here, and then write code in the method to say what should happen when the action occurs

Tutorial: This Apple Tutorial explains in detail how to connect UI Elements to Code

Uncategorized

February 2, 2018 Meeting

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