StarWarsCardGame

A Star Wars themed card game designed to see if you know your sith vs jedi.

Learning Objectives: Alert Controllers, Protocol/Delegate communication pattern, and an introduction to UICollectionView

Please go to https://github.com/DevMountain/StarWarsCardGame to fork and clone this repository. Once cloned, switch over to the starter branch in order to have access to the character images, as well as some pre-built code.

Model

We will start by constructing a Character model with three properties:

  • Name of type String
  • Photo of type optional UIImage
  • Faction of type String

Character will also need to conform the the Equatable protocol

ModelController

The CharacterController will have two static arrays, one for Jedi and one for Sith. Reference the photo assets in the Assets folder to see what characters can be created with photos. We need to use the string value of the photo asset to initialize the UIImage for model objects.

Views: CollectionViewController

Add a UICollectionViewController to the Main.storyboard canvas and embed it in a Navigation Controller.

  • With the CollectionView selected, navigate to the Size Inspector and change the Estimate Size to None. This will allow us to better control the size of our cells.
  • Add a Bar Button Item to the navigation bar, change the image in the attributes inspector to line.horizontal.3.decrease.
    • This would be a good time to mention SFSymbols being available natively in swift.

Create a new CocoTouchClass file, subclass UICollectionView, and title it CharacterCollectionViewController. Delete all the boiler plate code aside from numberOfItemsInSection, cellForItemAt, didSelectItemAt, and prepare(for segue:)

For now, we will focus on displaying characters on the collection view.

  • We will need an array to store the displayed faction of characters, a property to hold the target character, and a property to help us determine what faction is selected
    • Create the displayedCharacters array
    • Create the selectedFaction proterty with the default value of jedi
    • Create the targetCharacter property

We now need to populate our displayedCharacters array with 3 characters of the selected faction, and one from the other.
Write the shuffleCharacters(for faction:) method.

  • Walk through the conditional, explaining we need grab from the different arrays on our model controller for whatever faction is currenlty selected
  • We are using the .prefix() method on Array which returns an ArraySlice that we then need to transform back into an Array
  • We are using the .randomElement() method on Array to grab a random character out of the oposite faction array to set as our
  • We will then call updateViews()

Write the updateViews() method

  • Unwrap the target character and append it to the displayedCharacters array
  • We will then call .shuffle() on the displayedCharacters array to randomize the order of our Character objects
  • Assign the title to the targetCharacter‘s name property
  • Finally, call collectionView.reloadData()

CollectionViewDataSource

  • For numberOfItemsInSection we will use displayedCharacters.count
  • For cellForItemAt we will need to crete a custom collectionViewCell

Views: CollectionViewCell

In the Main.storyboard, add a prototype cell to the CollectionView of the CharacterCollectionViewController there isn’t one already.

  • Add An image to the cell, and constrain it to 0 to the top, leading, bottom, and trailing edges

Create a CocoTouchClass file, subclass UICollectionViewCell, and title the file CharacterCollectionViewCell. Delete all the starting code in the file.

  • Give the cell a reuseIdentifier
  • Create the needed outlet for the UIImageView
  • Create the helper function displayImage(for character:) to take the given character and set the image on the cell.

Views: CollectionViewController Part 2

Add the needed code to populate the cellForItemAt method

  • Dequeue a reusable collectionViewCell as the CharacterCollectionViewCell
  • Subscript into the array of characters, displayedCharacters[indexPath.row], to get the character for a given cell
  • Call cell.displayImage(for:) and pass in the character
  • Return the cell

Running the app at this point will display four characters. However, the sizing of the cells will be off. Time to fix that by extending the CharacterCollectionViewController and adopting the UICollectionViewDelegateFlowLayout protocol.

  • Implement the sizeForItemAt method
  • Size the cells however you see fit.

Running the app now will display the character cell properly. We still can’t play the game without implementing the didSelectItemAt to let us know if we selected the correct target.

  • In didSelectItemAt, subscritpt into the displayedCharacters to grab the selected character at the selected IndexPath
  • Now create the presentAlert(for character:) method
    • Be sure to outline initializing the UIAlertController, initializing the UIAlertActions, and adding the alert actions to the UIAlertController.

Views: FilterViewController

We are now to the point where we can implement the filter to select what faction we are setting for the game.

  • Navigate to Main.storyboard and add a new ViewController to the canvas.
  • Drag a segue from the filter bar button item to the new ViewController
    • The Segue should be a modal presentation segue
    • Set the segue identifier
  • Create the button stack view for the factions using the “sith” and ‘jedi” image assets
  • Create a new CocoaTouch file, subclass UIViewController, name the file FilterViewController
  • Open the assistant editor and create the actions for the buttons.

We now need a way to inform the CharacterCollectionViewController of when a selection has been made on the FilterViewController. Time to create a custom protocol/delegate pattern.

  • Create the FilterSelectionDelegate protocol with the selected(faction:) method
  • Add the delegate property on the FilterViewController
  • Implement the delegate method in both actions, passing the respective faction string value, and call dismiss in each action

Views: CollectionViewController Part 3

We need to now set the CharacterCollectionViewController as the delegate for the FilterViewController

  • Extend the CharacterCollectionViewController and adopt the FilterSelectionDelegate protocol, plug in the stubs
    • In the selected(faction:) method body, set the selectedFaction property to the faction parameter
    • Call shuffleCharacters(for:) and pass the faction parameter as the needed string argument
  • Now, assign the delegate using the prepare(for segue:) method.

At this point the project should run as expected.

Copyright

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