Swift updating UITableView with new data - ios

Question

I'm trying to repopulate my UITableView with data from another JSON call.
However my current setup doesn't seem to work, and while there are many identical questions on SO the answers I could find I've already tried.
I'm saving my API data in CoreData entity objects. And I'm filling my UITableView with my CoreData entities.
In my current setup I have 3 different API Calls that has a different amount of data, and of course different values. I need to be able to switch between these 3 datasets, and that's what I'm trying to accomplish now. (so far without progress).
I have a function called "loadSuggestions", which is where I assume my fault lies.
First I check for an internet connection.
I set the managedObjectContext
I check what API I need to call (This is determined before the function is called, and I checked that it works as intended)
I delete all the current data from the entity that it's trying to call. (I also tried to delete the data from the last data the UITableView had loaded. That didn't change anything). I also checked that this works. After deleting the data, I checked that it prints out an empty array, I also tried logging the objects it deletes to make sure.
I then fetch the new data, save it into temporary variables. Then save it to my core data.
Then I make my second API call (dependant on a variable from the first one), fetch that data and save it the same way.
I append the object to the array the UITableView fills it's cells from. (I checked that it prints out correctly as well)
And lastly I reload the tableView. (doesn't change a thing)
Here's the function:
func loadSuggestions() {
println("----- Loading Data -----")
// Check for an internet connection.
if Reachability.isConnectedToNetwork() == false {
println("ERROR: -> No Internet Connection <-")
} else {
// Set the managedContext again.
managedContext = appDelegate.managedObjectContext!
// Check what API to get the data from
if Formula == 0 {
formulaEntity = "TrialFormulaStock"
println("Setting Entity: \(formulaEntity)")
formulaAPI = NSURL(string: "http://api.com/json/entry_weekly.json")
} else if Formula == 1 {
formulaEntity = "ProFormulaStock"
println("Setting Entity: \(formulaEntity)")
formulaAPI = NSURL(string: "http://api.com/json/entry_weekly.json")
} else if Formula == 2 {
formulaEntity = "PremiumFormulaStock"
formulaAPI = NSURL(string: "http://api.com/json/proff_weekly.json")
println("Setting Entity: \(formulaEntity)")
} else if Formula == 3 {
formulaEntity = "PlatinumFormulaStock"
println("Setting Entity: \(formulaEntity)")
formulaAPI = NSURL(string: "http://api.com/json/fund_weekly.json")
}
// Delete all the current objects in the dataset
let fetchRequest = NSFetchRequest(entityName: formulaEntity)
let a = managedContext.executeFetchRequest(fetchRequest, error: nil) as! [NSManagedObject]
for mo in a {
managedContext.deleteObject(mo)
}
// Removing them from the array
stocks.removeAll(keepCapacity: false)
// Saving the now empty context.
managedContext.save(nil)
// Set up a fetch request for the API data
let entity = NSEntityDescription.entityForName(formulaEntity, inManagedObjectContext:managedContext)
var request = NSURLRequest(URL: formulaAPI!)
var data = NSURLConnection.sendSynchronousRequest(request, returningResponse: nil, error: nil)
var formula = JSON(data: data!)
// Loop through the api data.
for (index: String, actionable: JSON) in formula["actionable"] {
// Save the data into temporary variables
stockName = actionable["name"].stringValue
ticker = actionable["ticker"].stringValue
action = actionable["action"].stringValue
suggestedPrice = actionable["suggested_price"].floatValue
weight = actionable["percentage_weight"].floatValue
// Set up CoreData for inserting a new object.
let stock = NSManagedObject(entity: entity!,insertIntoManagedObjectContext:managedContext)
// Save the temporary variables into coreData
stock.setValue(stockName, forKey: "name")
stock.setValue(ticker, forKey: "ticker")
stock.setValue(action, forKey: "action")
stock.setValue(suggestedPrice, forKey: "suggestedPrice")
stock.setValue(weight, forKey: "weight")
// Get ready for second API call.
var quoteAPI = NSURL(string: "http://dev.markitondemand.com/Api/v2/Quote/json?symbol=\(ticker)")
// Second API fetch.
var quoteRequest = NSURLRequest(URL: quoteAPI!)
var quoteData = NSURLConnection.sendSynchronousRequest(quoteRequest, returningResponse: nil, error: nil)
if quoteData != nil {
// Save the data from second API call to temporary variables
var quote = JSON(data: quoteData!)
betterStockName = quote["Name"].stringValue
lastPrice = quote["LastPrice"].floatValue
// The second API call doesn't always find something, so checking if it exists is important.
if betterStockName != "" {
stock.setValue(betterStockName, forKey: "name")
}
// This can simply be set, because it will be 0 if not found.
stock.setValue(lastPrice, forKey: "lastPrice")
} else {
println("ERROR ----------------- NO DATA for \(ticker) --------------")
}
// Error handling
var error: NSError?
if !managedContext.save(&error) {
println("Could not save \(error), \(error?.userInfo)")
}
// Append the object to the array. Which fills the UITableView
stocks.append(stock)
}
// Reload the tableview with the new data.
self.tableView.reloadData()
}
}
Currently, when I push to this viewController, this function is called in viewDidAppear like so:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(true)
tableView.allowsSelection = true
if isFirstTime {
loadSuggestions()
isFirstTime = false
}
}
It populates the tableView correctly and everything seems to work as planned.
However if I open my slide-out menu and call a function to load different data, nothing happens, here's an example function:
func platinumFormulaTapGesture() {
// Menu related actions
selectView(platinumFormulaView)
selectedMenuItem = 2
// Setting the data to load
Formula = 3
// Sets the viewController. (this will mostly be the same ViewController)
menuTabBarController.selectedIndex = 0
// Set the new title
navigationController?.navigationBar.topItem!.title = "PLATINUM FORMULA"
// And here I call the loadSuggestions function again. (this does run)
SuggestionsViewController().loadSuggestions()
}
Here's the 2 relevant tableView functions:
number of Rows:
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return stocks.count
}
And cellForRowAtIndexPath, (this is where I set up my cells with the CoreData)
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("com.mySuggestionsCell", forIndexPath: indexPath) as! mySuggestionsCell
let formulaStock = stocks[indexPath.row]
cell.stockNameLabel.text = formulaStock.valueForKey("name") as! String!
cell.tickerLabel.text = formulaStock.valueForKey("ticker") as! String!
action = formulaStock.valueForKey("action") as! String!
suggestedPrice = formulaStock.valueForKey("suggestedPrice") as! Float
let suggestedPriceString = "Suggested Price\n$\(suggestedPrice.roundTo(2))" as NSString
var suggestedAttributedString = NSMutableAttributedString(string: suggestedPriceString as String)
suggestedAttributedString.addAttributes(GrayLatoRegularAttribute, range: suggestedPriceString.rangeOfString("Suggested Price\n"))
suggestedAttributedString.addAttributes(BlueHalisRBoldAttribute, range: suggestedPriceString.rangeOfString("$\(suggestedPrice.roundTo(2))"))
cell.suggestedPriceLabel.attributedText = suggestedAttributedString
if action == "SELL" {
cell.suggestionContainer.backgroundColor = UIColor.formulaGreenColor()
}
if let lastPrice = formulaStock.valueForKey("lastPrice") as? Float {
var lastPriceString = "Last Price\n$\(lastPrice.roundTo(2))" as NSString
var lastAttributedString = NSMutableAttributedString(string: lastPriceString as String)
lastAttributedString.addAttributes(GrayLatoRegularAttribute, range: lastPriceString.rangeOfString("Last Price\n"))
percentDifference = ((lastPrice/suggestedPrice)*100.00)-100
if percentDifference > 0 && action == "BUY" {
lastAttributedString.addAttributes(RedHalisRBoldAttribute, range: lastPriceString.rangeOfString("$\(lastPrice.roundTo(2))"))
} else if percentDifference <= 0 && percentDifference > -100 && action == "BUY" {
lastAttributedString.addAttributes(GreenHalisRBoldAttribute, range: lastPriceString.rangeOfString("$\(lastPrice.roundTo(2))"))
} else if percentDifference <= 0 && percentDifference > -100 && action == "SELL" {
lastAttributedString.addAttributes(RedHalisRBoldAttribute, range: lastPriceString.rangeOfString("$\(lastPrice.roundTo(2))"))
} else if percentDifference == -100 {
lastPriceString = "Last Price\nN/A" as NSString
lastAttributedString = NSMutableAttributedString(string: lastPriceString as String)
lastAttributedString.addAttributes(GrayLatoRegularAttribute, range: lastPriceString.rangeOfString("Last Price\n"))
lastAttributedString.addAttributes(BlackHalisRBoldAttribute, range: lastPriceString.rangeOfString("N/A"))
}
cell.lastPriceLabel.attributedText = lastAttributedString
} else {
println("lastPrice nil")
}
weight = formulaStock.valueForKey("weight") as! Float
cell.circleChart.percentFill = weight
let circleChartString = "\(weight.roundTo(2))%\nWEIGHT" as NSString
var circleChartAttributedString = NSMutableAttributedString(string: circleChartString as String)
circleChartAttributedString.addAttributes(BlueMediumHalisRBoldAttribute, range: circleChartString.rangeOfString("\(weight.roundTo(2))%\n"))
circleChartAttributedString.addAttributes(BlackSmallHalisRBoldAttribute, range: circleChartString.rangeOfString("WEIGHT"))
cell.circleChartLabel.attributedText = circleChartAttributedString
cell.selectionStyle = UITableViewCellSelectionStyle.None
return cell
}
I define my appDelegate as the very first thing in my class:
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
var managedContext = NSManagedObjectContext()
I think that's all the code that could possibly be the cause of the bug. Again I think the most likely cause would be in the loadSuggestions function.
To force update the tableView I also tried calling setNeedsDisplay and setNeedsLayout both on self.view and tableView, neither of which seemed to do anything at all.
Any advice in figuring out why this tableView refuses to update would be an enormous help!
And I apologize for the walls of code, but I havn't been able to find the exact origin of the issue.

Answer 1

This line in the platinumFormulaTapGesture function is incorrect,
SuggestionsViewController().loadSuggestions()
This creates a new instance of SuggestionsViewController, which is not the one you have on screen. You need to get a pointer to the one you have. How you do that depends on your controller hierarchy, which you haven't explained fully enough.