input-mask-ios

The library allows to format user input on the fly according to the provided mask and to extract valuable characters.

Mask examples:

1. International phone numbers: +1 ([000]) [000] [00] [00]
2. Local phone numbers: 8 ([000]) [000]-[00]-[00]
3. Visa card numbers: [0000] [0000] [0000] [0000]
4. Names: [A][-----------------------------------------------------]
5. Text: [A…]
6. Dates: [00]{/}[00]{/}[9900]

Masks consist of blocks of symbols, which may include:

• [] — a square brackets block for valuable symbols written by user.

Square brackets block may contain any number of special symbols:

1. 0 — mandatory digit. For instance, [000] mask will allow user to enter three numbers: 123.
2. 9 — optional digit . For instance, [00099] mask will allow user to enter from three to five numbers.
3. А — mandatory letter. [AAA] mask will allow user to enter three letters: abc.
4. а — optional letter. [АААааа] mask will allow to enter from three to six letters.
5. _ — mandatory symbol (digit or letter).
6. - — optional symbol (digit or letter).
7. … — ellipsis. Allows to enter endless count of symbols. For details and rules see Elliptical masks.

Other symbols inside square brackets will cause a mask initialization error, unless you have used custom notations.

Blocks may contain mixed types of symbols; such that, [000AA] will end up being divided in two groups: [000][AA] (this happens automatically). Though, it's highly recommended not to mix default symbols with symbols defined by custom notations.

Blocks must not contain nested brackets. [[00]000] format will cause a mask initialization error.

Symbols outside the square brackets will take a place in the output.
For instance, +7 ([000]) [000]-[0000] mask will format the input field to the form of +7 (123) 456-7890.

• {} — a block for valuable yet fixed symbols, which could not be altered by the user.

Symbols within the square and curly brackets form an extracted value (or «valuable characters»).
In other words, [00]-[00] and [00]{-}[00] will form the same output 12-34,
but in the first case the value, extracted by the library, will be equal to 1234, and in the second case it will result in 12-34.

Character escaping

Mask format supports backslash escapes when you need square or curly brackets in the output.

For instance, \[[00]\] mask will allow user to enter [12]. Extracted value will be equal to 12.

Note that you've got to escape backslashes in the actual code:

let format: String = "\\[[00]\\]"

Escaped square or curly brackets might be included in the extracted value. For instance, \[[00]{\]} mask will allow user
to enter the same [12], yet the extracted value will contain the latter square bracket: 12].

Installation

CocoaPods

pod 'InputMask'

Carthage

git "https://github.com/RedMadRobot/input-mask-ios.git"

Swift Package Manager

dependencies: [
    .Package(url: "https://github.com/RedMadRobot/input-mask-ios", majorVersion: 4)
]

Usage

Simple UITextField for the phone numbers

Drop an object on your scene and cofigure it as a MaskedTextFieldDelegate:

Assign your UITextField.delegate to be this object:

Make sure your ViewController knows its residents:

open class ViewController: UIViewController {
    @IBOutlet weak var listener: MaskedTextFieldDelegate!
    @IBOutlet weak var field: UITextField! 
}

Check that your object has configured Primary Mask Format. Prepare for receiving text changed events by assigning your ViewController as a delegate to MaskedTextFieldDelegate object:

Make your ViewController to implement MaskedTextFieldDelegateListener:

open class ViewController: UIViewController, MaskedTextFieldDelegateListener {    
    @IBOutlet weak var listener: MaskedTextFieldDelegate!
    @IBOutlet weak var field: UITextField!
    
    open func textField(
        _ textField: UITextField,
        didFillMandatoryCharacters complete: Bool,
        didExtractValue value: String
    ) {
        print(value)
    }
}

All set. Run.

Sample project is located under under Source/Sample.

Affine masks

You may want to switch between mask formats depending on the user input. Say, most of your phone numbers have primary format like this:

+7 ([000]) [000] [00] [00]

But some of them may have an operator code:

+7 ([000]) [000] [00] [00]#[900]

You put your additional mask formats into the affineFormats property:

open class ViewController: UIViewController, MaskedTextFieldDelegateListener {
    @IBOutlet weak var listener: MaskedTextFieldDelegate!
    
    open override func viewDidLoad() {
        super.viewDidLoad()
        listener.affinityCalculationStrategy = .prefix
        listener.affineFormats = [
            "+7 ([000]) [000] [00] [00]#[900]"
        ]
    }    
}

You may also want to set the affinityCalculationStrategy. AffinityCalculationStrategy.prefix configuration works better when your affine formats have distinctive prefixes, e.g. +1 ( and 8 (, though the default one, .whole, performs better when the entire value is inserted from the clipboard.

String formatting without views

In case you want to format a String somewhere in your application's code, Mask is the class you are looking for.
Instantiate a Mask instance and feed it with your string, mocking the cursor position:

let mask: Mask = try! Mask(format: "+7 ([000]) [000] [00] [00]")
let input: String = "+71234567890"
let result: Mask.Result = mask.apply(
    toText: CaretString(
        string: input,
        caretPosition: input.endIndex
    ),
    autocomplete: true // you may consider disabling autocompletion for your case
)
let output: String = result.formattedText.string

Mask(
    format: "[999][.][99]",
    customNotations: [
        Notation(
            character: ".", 
            characterSet: CharacterSet(charactersIn: ".,"), 
            isOptional: true
        ),
    ]
)

Mask.getOrCreate(
    withFormat: "[999][.][99]",
    customNotations: [
        Notation(
            character: ".", 
            characterSet: CharacterSet(charactersIn: ".,"), 
            isOptional: true
        ),
    ]
)

class ViewController: UIViewController {
    @IBOutlet weak var listener: MaskedTextFieldDelegate!
    
    open override func viewDidLoad() {
        super.viewDidLoad()
        listener.customNotations = [
            Notation(
                character: ".", 
                characterSet: CharacterSet(charactersIn: ".,"), 
                isOptional: true
            ),
        ]
    }
}

Notation(character: ".", characterSet: CharacterSet(charactersIn: "."), isOptional: true)

1
123
1234.
1234.5
1234.56

Notation(
    character: "D",
    characterSet: CharacterSet(charactersIn: "."),
    isOptional: false
),
Notation(
    character: "d",
    characterSet: CharacterSet(charactersIn: "."),
    isOptional: true
),
Notation(
    character: "@",
    characterSet: CharacterSet(charactersIn: "@"),
    isOptional: false
)

d
derh
derh.
derh.a
derh.asd
derh.asd@
derh.asd@h
derh.asd@hello.
derh.asd@hello.c
derh.asd@hello.com.
derh.asd@hello.com.u
derh.asd@hello.com.uk

Notation(character: "s", characterSet: CharacterSet(charactersIn: "$€"), isOptional: true)

12
$12
918
€918
1000
$1000

class NotifyingMaskedTextFieldDelegate: MaskedTextFieldDelegate {
    weak var editingListener: NotifyingMaskedTextFieldDelegateListener?
    
    override func textField(
        _ textField: UITextField,
        shouldChangeCharactersIn range: NSRange,
        replacementString string: String
    ) -> Bool {
        defer {
            self.editingListener?.onEditingChanged(inTextField: textField)
        }
        return super.textField(textField, shouldChangeCharactersIn: range, replacementString: string)
    }
}


protocol NotifyingMaskedTextFieldDelegateListener: class {
    func onEditingChanged(inTextField: UITextField)
}

In case you are using our library as a Carthage-built dynamic framework, be aware you won't be able to easily wire your MaskedTextFieldDelegate objects and their listeners from storyboards in your project. There is a couple of workarounds described in the corresponding discussion, though.

Also, consider filing a radar to Apple, like this one.

Cut action doesn't put text into the pasteboard

When you cut text, characters get deleted yet you won't be able to paste them somewhere as they aren't actually in your pasteboard.

iOS hardwires UIMenuController's cut action to the UITextFieldDelegate's textField(_:shouldChangeCharactersIn:replacementString:) return value. This means "Cut" behaviour actually depends on the ability to edit the text.

Bad news are, our library returns false in textField(_:shouldChangeCharactersIn:replacementString:), and heavily depends on this false. It would require us to rewrite a lot of logic in order to change this design, and there's no guarantee we'll be able to do so.

Essentially, there's no distinct way to differentiate "Cut selection" and "Delete selection" actions on the UITextFieldDelegate side. However, you may consider using a workaround, which will require you to subclass UITextField overriding its cut(sender:) method like this:

class UITextFieldMonkeyPatch: UITextField {
    override func cut(_ sender: Any?) {
        copy(sender)
        super.cut(sender)
    }
}

From our library perspective, this looks like a highly invasive solution. Thus, in the long term, we are going to investigate a "costly" method to bring the behaviour matching the iOS SDK logic. Yet, here "long term" might mean months.

MaskedTextInputListener

In case you are wondering why do we have two separate UITextFieldDelegate and UITextViewDelegate implementations, the answer is simple: prior to iOS 11 UITextField and UITextView had different behaviour in some key situations, which made it difficult to implement common logic.

Both had the same bug with the UITextInput.beginningOfDocument property, which rendered impossible to use the generic UITextInput protocol UITextField and UITextView have in common.

Since iOS 11 most of the things received their fixes (except for the UITextView edge case). In case your project is not going to support anything below 11, consider using the modern MaskedTextInputListener.

GitHub