Easy Core Data CSV Exporter in Swift

A new app I’m working on has a Core Data back end and I wanted to implement a quick way to export all the entities into a CSV file and dump it into the Desktop. 

Here are the snippets to do it:

1. Make sure you get the NSObjects you want to export (in this case I use a function that will return an array with the fetched NSObjectSubclass Transaction)

   private func provideAllTransactions() -> Array<Transaction>{

        let fetchRequest = NSFetchRequest(entityName: “Transaction”)

        fetchRequest.sortDescriptors = [NSSortDescriptor(key: “date”, ascending: false), NSSortDescriptor(key: “concept”, ascending: true)]

        return try! managedObjectContext.executeFetchRequest(fetchRequest) as! Array<Transaction>

    }

2. Convert to text, properly separating by commas and lines

    private func convertTransactionsToCsvString(transactions: Array<Transaction>)->String{

        var result = “HEADER 1, HEADER 2, HEADER 3, \r”//Headers

        

        for transactionIterator in transactions{ //Data

            result = result + “\”” + (transactionIterator.accountItBelongsTo?.name)! + “\”” + “,”

            result = result + “\”” + ((transactionIterator.date)?.description)! ?? NSDate().description

            result = result + “\”” + “,” + “\”” + (transactionIterator.concept)! + “\””

            result = result + “\”” + “\r”

        }

        

        return result

    }

3. Save to a path 

    func exportAllToCsv() -> Bool{

        

        let contentsToWrite = convertTransactionsToCsvString(provideAllTransactions())

        

        //Select path

        let path = “/Users/USER_NAME/Desktop/csvTest.csv”

        //Try to save it

        do {

            try contentsToWrite.writeToFile(path, atomically: true, encoding: NSUTF8StringEncoding)

        }catch{

            print(“ERROR: Export could not be saved in %”, path)

        }

        

        return true

 

    }

Note that in this example the path is hardcoded to the desktop of the user named USER_NAME, you should have the user choose where he wants to save it or you can hardcode a location in your disk. 

If you would have a NSDictionary it would be almost the same but starting at point 2 with the dictionary results. 

Questions / comments? I’m at @MarcMasVi

Marc

 

PS. Here is how you would have the path be selected by the user:        

 

    privatefunc userToChooseAFileInModalPannel() -> String?{

        let pannel: NSOpenPanel = NSOpenPanel()

        pannel.canChooseDirectories = true

        pannel.canChooseFiles = false

        pannel.allowsMultipleSelection = false

        pannel.runModal()

        

        return pannel.URL?.path

    }

 then in point 3 you would do 

//Select path

        let path = userToChooseAFileInModalPannel() + “/test.csv”


Back to coding!

You may have noticed a steep drop in post frequency this last couple of months. The reason is that I just got married and well… I code and write this blog on my spare time and, with planning and all, have not had much of that this last months. 

Should be back to normal in a weeks time! I’m enjoying a lot the honey moon, but damn it I also miss coding!

Is it too late for me to be saved?