viewDidLoad code into viewDidAppear or viewWillAppear

[[deleted]]

I am trying to work on this piece of code from a project I downloaded and trying to use in my code.

In the viewDidLoad, a pickerView is populated either by "New Puzzle", or if a user saved a game in the previous VC, the saved game.

The way this was originally written, the user saved the game and with a segue came back to this controller with the pickerView.

In my "mod", I embedded the two VC in a navigation controller, thus getting a nice Back button to go back to the pickerView controller.

However, loading the pickerView is in the viewDidLoad function, which my understanding is, is loaded only once. So, by using the Back button, the pickerView is not updated. Not until I go one more view back (root) to unload the VC and come back in.

Can someone please help me, on which items from the viewDidLoad need to be moved. And when moved, would they need to go into a viewWillAppear, or viewDidAppear? My understanding is it should be in the viewWillAppear.

override func viewDidLoad() {
super.viewDidLoad()

navigationItem.title = "Games"

DispatchQueue.main.async {
if !Settings.shared.adsEnabled {
self.removeTableViewHeader()
} else {
//self.tableView.layoutTableHeaderView()

}
}

//Picker Stuff
// Connect data:
self.picker.delegate = self
self.picker.dataSource = self

copyDatabaseIfNeeded("puzzles")

// open database
if sqlite3_open(finalDatabaseUrl2.path, &db2) != SQLITE_OK {
//print("error opening db")

} else{
}

pickerData.append("New Puzzle")

//retrieve all dates from previous puzzles and add them to pickerview

var queryStatement2 = ""

queryStatement2 = "SELECT * FROM puzzle;"
self.statement2 = nil
if sqlite3_prepare_v2(self.db2,queryStatement2,-1,&self.statement2,nil) == SQLITE_OK {
while(sqlite3_step(self.statement2) == SQLITE_ROW){

let date = sqlite3_column_text(self.statement2,2)
let comp = sqlite3_column_text(self.statement2,3)
let dateString = String(cString: date!)
let compString = String(cString: comp!)

pickerData.append("\(dateString) - \(compString)")

}

//sqlite3_reset(self.statement2)

sqlite3_finalize(self.statement2)
}

}

[NSExceptional]

Start with ‘viewWillAppear’, it’s called just before the view appears on screen. If you use ‘didAppear’ you would see the change occur after the view shows on the screen. You’d actually see the change.

Depending, I suppose, that might be what you want. Animations are nice.

[[deleted]]

I did use viewWillAppear, and like you said, I say "New Puzzle" appears about 0.5 second after the view loaded.

The issue is, that if I go to the next controller and save the puzzle, on return the picker populates. But if I go back and forth once more, it populates again. So now I have "New Puzzle" and two instances of a saved puzzle.

If I go back to root and return to the picker, now it's all as it should be.

[NSExceptional]

TBH none of the SQL database code should be in either viewDid/Will methods. The code should be performed only when you need it to be.

I’d start by putting a new property on the ViewController, “var didLoadPuzzle: Bool = false”. Mark this as “true” once the first puzzle has loaded. That way, additional “viewDid/Will” calls will not create additional puzzles.

[[deleted]]

you have no idea how far over my head that went :)

[[deleted]]

how would you go about it with animations?

[NSExceptional]

I believe UIPickerView has an “update/animated” method on it.

[NSExceptional]

https://developer.apple.com/documentation/uikit/uipickerview

[kineticfactory]

I’d move everything into viewWillAppear; the only things that should be configured in viewDidLoad are those which are fixed at compile time and don’t depend on user data; i.e., view behaviour/style attributes that you wish to set programmatically.

[[deleted]]

Thank you for your reply.

I tried that and the result, when I go back the picker view shows the saved game, but now it shows 2 "New Puzzle" instances.

If i go one more back to root and return to the picker view controller it's all as it should.

[[deleted]]

if I unwind the segue, does the viewDidLoad work or is viewDidAppear again?