How to add text into a .csv data in Swift? - ios

Question

I want to add some text like "Hi;Test;Pen" into my .csv file.
I have used the CSVImporter to insert the text of the .csv into my Xcode project. Here is the code, I have used for it:
guard let VokabelPath = Bundle.main.path(forResource: ResourceExample, ofType:"csv") else {
debugPrint(ResourceExample + " not found")
return
}
let importer = CSVImporter<[String]>(path: VokabelPath, delimiter: ";")
let importedRecords = importer.importRecords { $0 }
for record in importedRecords {
self.Vokabeln.insert(record, at: self.Vokabelzähler)
self.Vokabelzähler += 1
}
But for some reasons I want to
add something to the file
Change something in the file (e.g. in Line 4)
Delete the text in the file (e.g. filetext = ""
I have tried to use this Tutorial and I have made this code:
let fileName = "Tasks.csv"
let path = NSURL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(fileName)
var csvText = "Test;Example;Apple;Pen\n"
do {
try csvText.write(to: path!, atomically: true, encoding: String.Encoding.utf8)
} catch {
print("Failed to create file")
print("\(error)")
}
guard let VokabelPath = Bundle.main.path(forResource: "Tasks", ofType:"csv") else {
debugPrint("Tasks not found")
return
}
let importer = CSVImporter<[String]>(path: VokabelPath, delimiter: ";")
let importedRecords = importer.importRecords { $0 }
for record in importedRecords {
self.Vokabeln.insert(record, at: self.Vokabelzähler)
self.Vokabelzähler += 1
print(record)
}
but he prints only "Tasks not found". What is my mistake?
I hope you can help me,
Thank you.
EDIT:
The person who made the first answer has written, I can't save files in the bundle.
He has written to me I should use NSSearchPathForDirectoriesInDomainsso I have updated my code and this works:
let DownloadPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString
let VokabelPath = DownloadPath.appendingPathComponent("Tasks.csv")
let InhaltData = Inhalt.data(using: .utf8)
print(VokabelPath)
FileManager.default.createFile(atPath: VokabelPath, contents: InhaltData, attributes: nil)
let importer = CSVImporter<[String]>(path: VokabelPath, delimiter: ";")
let importedRecords = importer.importRecords { $0 }
for record in importedRecords {
self.Vokabeln.insert(record, at: self.Vokabelzähler)
self.Vokabelzähler += 1
}
But I have one further question:
I hav some datas in my Xcode project and I can get them with Bundle.main. But I want to use only one function, so is it possible, to get them with NSSearchPathForDirectoriesInDomainstoo?

Answer 1

In order to change a file, you would need to import the data in, make the necessary changes to the data and then write the data back to the same file, overwriting the previous content. That is how you would make changes generally - you don't make changes directly to the file.
Does that make sense?
If it does, then you could easily modify the tutorial you pointed to (the one for creating and exporting CSV) and write back the data that you read from the original file after you make the modifications.
As for your question about not wanting to use a library, you can always write your own CSV parser. It is not very difficult since all you have to do is read the text from the file a line at a time and then separate out the values by comma. A simple parser is straightforward but allowing for more complicated cases could take a bit more effort. It would all depend on your use-cases and the type of data you'd be handling. The easiest way still would be to use your importing library and then output via custom code.
Regarding your additional questions, if the following code fails:
guard let VokabelPath = Bundle.main.path(forResource: "Tasks", ofType:"csv") else {
debugPrint("Tasks not found")
return
}
Then there is either an issue with the file name (or extension) or you have not included the file as part of your Resources. The above code simply gets the path for a given file in your Resources.
The above code is different from what I was talking about with regards to NSSearchPathForDirectoriesInDomains - that was for writing a file from your app. What I meant was that you could not write a file back to your Resources - instead, you would have to write the modified file to your Documents folder. Hope that clarifies things :)