Simples And Fast String Mask Formatter.

StringMaskFormatter.swift

//
//  StringMaskFormatter.swift
//  StringMaskFormatter
//
//  Created by dede.exe on 10/07/16.
//  It's totally base on article : "http://vojtastavik.com/2015/03/29/real-time-formatting-in-uitextfield-swift-basics/"
//  And I don't mind if the original author should allow me(or not) to publish it :)... But I'll keep the reference
//

import UIKit

public struct StringMaskFormatter {
    
    public var pattern              : String    = ""
    public var replecementChar      : Character = "*"
    public var allowNumbers         : Bool      = true
    public var allowText            : Bool      = false
    
    
    public init(pattern:String, replecementChar:Character="*", allowNumbers:Bool=true, allowText:Bool=true)
    {
        self.pattern            = pattern
        self.replecementChar    = replecementChar
        self.allowNumbers       = allowNumbers
        self.allowText          = allowText
    }


    private func prepareString(string:String) -> String {
        
        var charSet : NSCharacterSet!
        
        if allowText && allowNumbers {
            charSet = NSCharacterSet.alphanumericCharacterSet().invertedSet
        }
        else if allowText {
            charSet = NSCharacterSet.letterCharacterSet().invertedSet
        }
        else if allowNumbers {
            charSet = NSCharacterSet.decimalDigitCharacterSet().invertedSet
        }
        
        let result = string.componentsSeparatedByCharactersInSet(charSet)
        return result.joinWithSeparator("")
    }
    
    public func createFormattedStringFrom(text:String) -> String
    {
        var resultString = ""
        if text.characters.count > 0 && pattern.characters.count > 0
        {
            
            var finalText   = ""
            var stop        = false
            let tempString  = prepareString(text)
            
            var formatIndex = pattern.startIndex
            var tempIndex   = tempString.startIndex
            
            while !stop
            {
                let formattingPatternRange = formatIndex ..< formatIndex.advancedBy(1)
                
                if pattern.substringWithRange(formattingPatternRange) != String(replecementChar) {
                    finalText = finalText.stringByAppendingString(pattern.substringWithRange(formattingPatternRange))
                }
                else if tempString.characters.count > 0 {
                    let pureStringRange = tempIndex ..< tempIndex.advancedBy(1)
                    finalText = finalText.stringByAppendingString(tempString.substringWithRange(pureStringRange))
                    tempIndex = tempIndex.advancedBy(1)
                }
                
                formatIndex = formatIndex.advancedBy(1)
                
                if formatIndex >= pattern.endIndex || tempIndex >= tempString.endIndex {
                    stop = true
                }
                
                resultString = finalText
                
            }
        }
        
        return resultString
    }
    
}


//MARK: - Pre defined formats
extension StringMaskFormatter {
    static func CPFPatternFactory() -> StringMaskFormatter {
        return StringMaskFormatter(pattern: "***.***.***-**", replecementChar: "*", allowNumbers: true, allowText: false)
    }
    
    static func CreditCardPatternFactory() -> StringMaskFormatter {
        return StringMaskFormatter(pattern: "**** **** **** ****", replecementChar: "*", allowNumbers: true, allowText: false)
    }
    
    static func MMYYDatePatternFactory() -> StringMaskFormatter {
        return StringMaskFormatter(pattern: "**/**", replecementChar: "*", allowNumbers: true, allowText: false)
    }
    
    static func CompleteDatePatternFactory() -> StringMaskFormatter {
        return StringMaskFormatter(pattern: "**/**/****", replecementChar: "*", allowNumbers: true, allowText: false)
    }
    
    static func SimpleDatePatternFactory() -> StringMaskFormatter {
        return StringMaskFormatter(pattern: "**/**/**", replecementChar: "*", allowNumbers: true, allowText: false)
    }
}