EurekaWhitespaceWorkaround.swift

//
//  EurekaWhitespaceWorkaround.swift
//
//  Created by Hannes Oud on 23.11.16.
//  Use this however you want.
import Eureka

/// Configures right-aligned text rows to make spaces visible on edit,
/// by temporary replacing them with non-breaking spaces. Call `EurekaWhitespaceWorkaround.configureTextCells()`.
/// - Note: this will set the `TextRow.defaultCellSetup`
final class EurekaWhitespaceWorkaround {

    static func configureTextCells() {
        let workaround = EurekaWhitespaceWorkaround()
        TextRow.defaultCellSetup = { cell, row in
            // the workaround object is retained here on purpose
            workaround.configureWhiteSpaceWorkaround(forTextCell: cell)
        }
    }

    private func configureWhiteSpaceWorkaround(forTextCell cell: TextCell) {
        cell.textField.addTarget(self, action: #selector(EurekaWhitespaceWorkaround.replaceNormalSpacesWithNonBreakingSpaces(textField:)), for: .editingChanged)
        cell.textField.addTarget(self, action: #selector(EurekaWhitespaceWorkaround.replaceNonBreakingSpacesWithNormalSpaces(textField:)), for: .editingDidEnd)
    }

    private dynamic func replaceNormalSpacesWithNonBreakingSpaces(textField: UITextField) {
        textField.text = textField.text?.replacingOccurrences(of: " ", with: "\u{00a0}")
    }

    private dynamic func replaceNonBreakingSpacesWithNormalSpaces(textField: UITextField) {
        textField.text = textField.text?.replacingOccurrences(of: "\u{00a0}", with: " ")
    }
}

This is a good solution, but the cursor jumps to the end if you add a space in the middle of the string. This will put the cursor back (Swift 4):

@objc private dynamic func replaceNormalSpacesWithNonBreakingSpaces(textField: UITextField) {
let cursor = textField.selectedTextRange
textField.text = textField.text?.replacingOccurrences(of: " ", with: "\u{00a0}")
textField.selectedTextRange = cursor
}