JMMaskTextField

Back in my JavaScript days (oh what dark ages) it was quite simple to apply a mask to an input with some jQuery plugin, you just had to set the mask to something like (999) 999-9999 and you had a great masked input for a phone number. I never found anything that simple on iOS. Some libs required you to write a regex pattern and other crazy stuff. Sure, that can be useful for more complex cases, but I just wanted something simple and straightforward. From that need came JMMaskTextField.

JMMaskTextField allows you to mask your UITextField by simply setting a mask pattern string. Mask characters are:

A for letters
0 for numbers
* for numbers and letters

So for a Brazilian license plate, which has 3 letters, a dash and then 4 numbers, the mask would be: AAA-0000.

JMMaskTextField also handles pasting, inserting and deleting from the middle.

There's also an Objective-C version

Installation

CocoaPods

You can install JMMaskTextField with CocoaPods

Add this line to your Podfile pod "JMMaskTextField-Swift"
Run pod install

Manual

Just drop the JMMaskTextField folder in your project and you're all set!

Usage

Funcionality is broken down into 2 classes:

JMStringMask - all the string masking functionality. You can use this yourself outside of the JMMaskTextField.
JMMaskTextField - the UITextField subclass, handling all editing events. Uses an instance of JMStringMask.

Interface Builder

Set the class of your text field to JMMaskTextField in the Identity Inspector. And then on the Attributes Inspector set your mask. And that's it!

Code

Initialize an instance of JMMaskTextField and set the mask property:

let maskTextField = JMMaskTextField(frame: CGRect.zero)
maskTextField.maskString = "(00) 0 0000-0000"

And that's it!

JMStringMask

You can use the string masking functionality outside of the text field. Usage is also simple:

let mask = JMStringMask(mask: "00000-000")
let maskedString = mask.mask(string: "30310360") // returns "30310-360"
let unmaskedString = mask.unmask(string: maskedString) // returns "30310360"

Changing the mask while editing

In Brazil we a problem: cell phone numbers are 9 digits (and until recently not all of them were 9 digits), and landlines are 8 digits. That creates a problem with masking. JMMaskTextField supports changing the mask while editing. So when we identify the user typed a 9 digit number, we switch the mask to the longer format. If they delete a digit, we go back to the original mask. An example:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    
    guard let text = textField.text as NSString? else { return true }
    let newText = text.replacingCharacters(in: range, with: string)
    
    let maskTextField = textField as! JMMaskTextField
    guard let unmaskedText = maskTextField.stringMask?.unmask(string: newText) else { return true }
    
    if unmaskedText.count >= 11 {
        maskTextField.maskString = "(00) 0 0000-0000"
    } else {
        maskTextField.maskString = "(00) 0000-0000"
    }
    
    return true
}

Author

Jota Melo, jpmfagundes@gmail.com

License

JMMaskTextField is available under the MIT license. See the LICENSE file for more info.

LeoValentim/JMMaskTextField-Swift