Reading and parsing a file from dropbox in swift - ios

Question

I am following a tutorial on how to read and parse a csv file from dropbox in swift. However, the tutorial is 4 years old and my code is not compiling in swift5. The code example is copied below and the link to the original video tutorial is here https://www.youtube.com/watch?v=O6AKHAXpji0
I am getting two errors.
Error 1:
on the let request = line of callFileFromWeb(){}
'NSURL' is not implicitly convertible to 'URL'; did you mean to use 'as' to explicitly convert?
Error 2:
and on let session = ... within the httpGet(){}
'NSURLSession' has been renamed to 'URLSession'
When I try to implement the proposed fix for error two then I get another error
Cannot call value of non-function type 'URLSession`
Any ideas what should I be adjusting for it to work in swift5?
var items:[(days:String, city:String, inches: String)]?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
callFileFromWeb()
}
func callFileFromWeb(){
let request = NSMutableURLRequest(URL: NSURL(string: "https://dl.dropboxusercontent.com/u/2813968/raindata.txt")!)
httpGet(request){
(data, error) -> Void in
if error != nil {
print(error)
} else {
print(data)//PRINTING ALL DATA TO CONSOLE
let delimiter = ":"
self.items = []
let lines:[String] = data.componentsSeparatedByCharactersInSet(NSCharacterSet.newlineCharacterSet()) as [String]
for line in lines {
var values:[String] = []
if line != "" {
values = line.componentsSeparatedByString(delimiter)
// Put the values into the tuple and add it to the items array
print(values[2])//PRINTING LAST COLUMN
let item = (days: values[0], city: values[1], inches: values[2])
self.items?.append(item)
}}//all good above
// self.AddDataToDatabase()
}//there was an error
}//end of request
}//end of get data from web and load in database
func httpGet(request: NSURLRequest!, callback: (String, String?) -> Void) {
let session = NSURLSession.sharedSession()
let task = session.dataTaskWithRequest(request){
(data, response, error) -> Void in
if error != nil {
callback("", error!.localizedDescription)
} else {
let result = NSString(data: data!, encoding:
NSASCIIStringEncoding)!
callback(result as String, nil)
}
}
task.resume()
}
The final goal is to be able to read a file from drop box. The file updates weakly, so when users launch the app they always have access to the most updated version of the file, rather than having to re download the app when the file updates. Is this the correct approach to do this?

Answer 1

A framework that proved useful in past projects with parsing CSV files is:
CSwiftV -> https://github.com/Daniel1of1/CSwiftV
Updated: 9/23/2020
Let me demonstrate it by refactoring your callFileFromWeb():
func callFileFromWeb() {
let dropboxURL = URL(string: "https://dl.dropboxusercontent.com/u/2813968/raindata.txt")
URLSession.shared.dataTask(with: dropboxURL!) { data, response, error in
guard let urlData = data, error == nil else {
return
}
let unparsedCSV = String(data: urlData, encoding: String.Encoding.utf8) ?? "Year,Make,Model,Description,Price\r\n1997,Ford,E350,descrition,3000.00\r\n1999,Chevy,Venture,another description,4900.00\r\n"
let csv = CSwiftV(with: unparsedCSV)
let rows = csv.rows
var iteration = 0
for row in rows {
// Assuming you want the last row
if iteration == rows.count - 1 {
let item = (days: row[0], city: row[1], inches: row[2])
self.items?.append(item)
}
iteration += 1
}
}
}
One other thing, remember that you need to download CSSwiftV from Github and copy the original CSwiftV.swift file into your project.
Hope this helps!