Working with Excel in Swift on iOS and macOS: Libraries and Code Examples

Working with Excel in Swift: Libraries and Tools for iOS and macOS

When developing applications for iOS and macOS, there is often a need to import, export, or process data in Excel format (XLSX, CSV). The Apple platform does not have built-in support for Excel formats, so developers use third-party libraries. This article covers three popular tools: CoreXLSX, XLSXWriter, and SwiftCSV, and provides practical code examples in Swift.

1. CoreXLSX — Reading and Writing XLSX

CoreXLSX is a lightweight library for reading and creating XLSX files. It is based on the Open XML standard and supports strings, numbers, dates, formulas, and styles.

Installation

// Swift Package Managerdependencies: [    .package(url: "https://github.com/CoreOffice/CoreXLSX.git", from: "0.14.0")]

Example: Reading Data from Excel

import CoreXLSX

func readExcel(path: String) {    guard let file = XLSXFile(filepath: path) else {        print("Error opening file")        return    }        do {        for path in try file.parseWorksheetPaths() {            let worksheet = try file.parseWorksheet(at: path)            let rows = worksheet.data?.rows ?? []            for row in rows {                let values = row.cells.compactMap { $0.value }                print(values.joined(separator: "\\t"))            }        }    } catch {        print("Read error: \\(error)")    }}

Example: Creating a New XLSX File

import CoreXLSX

func createExcel() {    let header = ["Name", "Age", "City"]    let data = [        ["Anna", "25", "Moscow"],        ["Boris", "30", "Saint Petersburg"]    ]        var sharedStrings = SharedStrings()    let headerRefs = header.map { sharedStrings.append(string: $0) }    let dataRefs = data.map { row in        row.map { sharedStrings.append(string: $0) }    }        let headerRow = Row(cells: headerRefs.enumerated().map { (index, ref) in        Cell(reference: "\\(Character(UnicodeScalar(65 + index)!))1", type: .string, value: ref)    })        let dataRows = dataRefs.enumerated().map { (rowIndex, row) in        Row(cells: row.enumerated().map { (colIndex, ref) in            let colRef = Character(UnicodeScalar(65 + colIndex)!)            return Cell(reference: "\\(colRef)\\(rowIndex + 2)", type: .string, value: ref)        })    }        let worksheet = Worksheet(data: Data(rows: [headerRow] + dataRows))    let file = XLSXFile(sharedStrings: sharedStrings, worksheets: [worksheet])        do {        try file.write(to: URL(fileURLWithPath: "/tmp/example.xlsx"))        print("File saved")    } catch {        print("Write error: \\(error)")    }}

2. XLSXWriter — Fast Writing of Large Files

XLSXWriter is a library focused on write performance. It is suitable for exporting thousands of rows and supports styles, cell merging, and charts.

Installation

// Via CocoaPodspod 'XLSXWriter'

Example: Writing Data with Formatting

import XLSXWriter

func writeFormattedExcel() {    let workbook = Workbook()    let sheet = workbook.addSheet(named: "Report")        // Styles    let headerStyle = CellStyle()    headerStyle.font = Font(name: "Helvetica", size: 14, bold: true)    headerStyle.fill = Fill(color: .lightGray)        let dataStyle = CellStyle()    dataStyle.font = Font(name: "Helvetica", size: 12)    dataStyle.border = Border(top: .thin, bottom: .thin)        // Headers    sheet.write(row: 0, column: 0, value: "Product", style: headerStyle)    sheet.write(row: 0, column: 1, value: "Price", style: headerStyle)    sheet.write(row: 0, column: 2, value: "Quantity"