How to use C library in Xcode Project? - ios

Question

The library is written in C https://github.com/jmcnamara/libxlsxwriter
The pod file that I am using is
pod 'libxlsxwriter', '0.3.1'
I import the header into the Bridging Header
#import <libxlsxwriter/xlsxwriter.h>
I am getting this
'libxlsxwriter/xlsxwriter.h' file not found

Answer 1

It is actually quite simple, yet poorly documented (IMHO):
Install the library with CocoaPods:
Add pod 'libxlsxwriter', '~> 0.9' to your pod file.
Run pod install
You do not need a Swift-Bridging-Header, simply use the library like so:
import UIKit
import xlsxwriter
...
override func viewDidLoad() {
super.viewDidLoad()
createExcelFile()
}
override func viewWillAppear(_ animated: Bool) {
}
/*#objc*/ func createExcelFile(){
// Create a new workbook.
let documentDirectory = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor:nil, create:false)
let fileURL = documentDirectory.appendingPathComponent("demo.xlsx")
//Ditch first 6 characters, because they are of the form file://
let workbook = workbook_new((fileURL.absoluteString.dropFirst(6) as NSString).fileSystemRepresentation)
// Add a worksheet with a user defined sheet name.
let worksheet1 = workbook_add_worksheet(workbook, "Demo")
// Add a worksheet with Excel's default sheet name: Sheet2.
let worksheet2 = workbook_add_worksheet(workbook, nil)
// Add some cell formats.
let myformat1 = workbook_add_format(workbook)
let myformat2 = workbook_add_format(workbook)
// Set the bold property for the first format.
format_set_bold(myformat1)
// Set a number format for the second format.
format_set_num_format(myformat2, "$#,##0.00")
// Widen the first column to make the text clearer.
worksheet_set_column(worksheet1, 0, 0, 20, nil)
// Write some unformatted data.
worksheet_write_string(worksheet1, 0, 0, "Peach", nil)
worksheet_write_string(worksheet1, 1, 0, "Plum", nil)
// Write formatted data.
worksheet_write_string(worksheet1, 2, 0, "Pear", myformat1)
// Formats can be reused.
worksheet_write_string(worksheet1, 3, 0, "Persimmon", myformat1)
// Write some numbers.
worksheet_write_number(worksheet1, 5, 0, 123, nil)
worksheet_write_number(worksheet1, 6, 0, 4567.555, myformat2)
// Write to the second worksheet.
worksheet_write_string(worksheet2, 0, 0, "Some text", myformat1)
// Close the workbook, save the file and free any memory
workbook_close(workbook)
loadingSpinner.stopAnimating()
self.shareExcelFile(filepath: fileURL)
}
func shareExcelFile(filepath: URL){
//Share the newly created file
var filesToShare = [Any]()
filesToShare.append(filepath)
let activityViewController = UIActivityViewController(activityItems: filesToShare, applicationActivities: [])
activityViewController.popoverPresentationController?.sourceView = self.view
activityViewController.popoverPresentationController?.sourceRect = CGRect(x: self.view.bounds.maxX, y: self.view.bounds.minY, width: 0, height: 0)
activityViewController.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection.init(rawValue: 0)
self.present(activityViewController, animated: true)
activityViewController.completionWithItemsHandler = { activity, completed, items, error in
if !completed {
// handle task not completed
return
}
self.dismiss(animated: false, completion: nil)
}
}
}
This should create an example .xlsx file, save it to the ~Documents directory and share it.
I did not test the code, so expect needing to change some bits.
I will setup a demo repository, once I get the time to do it...