Aug 25, 2021

2 min read

Convert Excel (97–2003) XLS to CSV in Swift

Even though the current XLSX version of Excel has been available since 2007, use of the XLS version is still relatively prominent. However, if you utilize the outdated XLS format, compatibility may become an issue when sharing files with partners and clients. To prevent any mishaps or delays of information, you can utilize the following API in Swift to instantly convert an XLS workbook to the data-friendly CSV format.

All you will need for the conversion is the target file and your API key, which you can then input into the below example code:

import Foundation
#if canImport(FoundationNetworking)
import FoundationNetworking
var semaphore = DispatchSemaphore (value: 0)let parameters = [
"key": "inputFile",
"src": "/path/to/file",
"type": "file"
]] as [[String : Any]]
let boundary = "Boundary-\(UUID().uuidString)"
var body = ""
var error: Error? = nil
for param in parameters {
if param["disabled"] == nil {
let paramName = param["key"]!
body += "--\(boundary)\r\n"
body += "Content-Disposition:form-data; name=\"\(paramName)\""
if param["contentType"] != nil {
body += "\r\nContent-Type: \(param["contentType"] as! String)"
let paramType = param["type"] as! String
if paramType == "text" {
let paramValue = param["value"] as! String
body += "\r\n\r\n\(paramValue)\r\n"
} else {
let paramSrc = param["src"] as! String
let fileData = try NSData(contentsOfFile:paramSrc, options:[]) as Data
let fileContent = String(data: fileData, encoding: .utf8)!
body += "; filename=\"\(paramSrc)\"\r\n"
+ "Content-Type: \"content-type header\"\r\n\r\n\(fileContent)\r\n"
body += "--\(boundary)--\r\n";
let postData = .utf8)
var request = URLRequest(url: URL(string: "")!,timeoutInterval: Double.infinity)
request.addValue("multipart/form-data", forHTTPHeaderField: "Content-Type")
request.addValue("YOUR-API-KEY-HERE", forHTTPHeaderField: "Apikey")
request.addValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
request.httpBody = postData
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data else {
print(String(describing: error))
print(String(data: data, encoding: .utf8)!)

And with that, the operation is complete! Easy.