A Swift package for reading and writing CSV using an enum typed format.
- Importing of CSV files and strings
- Exporting to string
- Automatic separator guessing
- Manual selection of exported columns
- All field access in rows is managed by a custom CSVFormat enumeration and typesafe
Import and export rely on a customly defined format enumeration, impementing the CSVFormat protocol. This format should correspond to the CSV row format you want to import or export.
private enum TestShoppingItem: String, CSVFormat {
case id
case name
case price
var title: String {
rawValue.capitalized
}
}To read a CSV string or file, you initialize a CSVData object with a CSV string or url and the previously defined CSVFormat enumeration. The separators for rows and columns are guessed automatically, but you can also manually set the properties rowSeparator and columnSeparator.
func read() throws {
// read CSV string
let testCSVString = "id,name,Price\n1,Bananas,1.20\n2,Sugar,2.30\n3,Milk,1.99"
var csvData = try CSVData<TestShoppingItem>(csvString: testCSVString)
// read CSV file on disk
let documentsFolder = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let csvUrl = documentsFolder.appending(path: "testCSV.csv")
csvData = try CSVData<TestShoppingItem>(url: csvUrl)
}To initialize a CSVData object with your own data, call the initializer with an array of any kind of data. Provide a closure as the data source to initialize each value of all column columns.
func createCSVData() -> CSVData<TestShoppingItem> {
let csvData = CSVData<TestShoppingItem>(items: Array(0 ..< 10)) { index, column in
switch column {
case .id:
return "\(index)"
case .name:
return "Item \(index + 1)"
case .price:
return "\(Double(index) * 1.5)"
}
}
return csvData
}You can manipulate the csv data object later in a typesafe way.
func manipulateCSVData() {
let csvData = createCSVData()
csvData[1][.name] = "Test"
}The CSVData can be exported to a string. Using the columnConfiguration argument, you can manually select columns to export.
func export() {
let csvData = createCSVData()
// export complete CSV string
let csvString = csvData.csvString()
// export only name column
let csvStringOnlyName = csvData.csvString(columnConfiguration: .includeOnly(columns: [.name]))
// export all columns but price
let csvStringAllButPrice = csvData.csvString(columnConfiguration: .allBut(columns: [.price]))
}The library can be used with Swift Package Manager in XCode or manually added as a package dependency.