Mastering Input Masks in React Native

What are Input Masks?

Input masks are string templates that guide users to enter valid data according to a pre-defined format. They typically block invalid keystrokes and display the allowed string format as a placeholder.

For example, an input mask for a phone number might display (123) 456-7890 as a placeholder, allowing users to enter their phone number in a specific format.

Implementing Input Masks in React Native

To implement input masks in React Native, we’ll use the react-native-text-input-mask library.

First, install the library using npm or yarn:

npm install react-native-text-input-mask

Next, import the library and create an input component with a mask:

import React, { useState } from 'eact';
import { TextInputMask } from 'eact-native-text-input-mask';

const MyInputComponent = () => {
  const [value, setValue] = useState('');

  return (
    <TextInputMask
      mask="+999 999 999 999"
      value={value}
      onChangeText={(text) => setValue(text)}
      placeholder="+xxx xxx xxx xxx"
    />
  );
};

In this example, the input mask is set to +999 999 999 999, which allows users to enter a phone number in a specific format.

Customizing Input Masks

You can customize input masks by using the following characters:

• 9: Matches a numeric character (0-9)
• A: Matches an alphanumeric character (A-Z, a-z, 0-9)
• *: Matches any character

For example, to create an input mask for a credit card number, you could use the following mask:

<TextInputMask
  mask="9999 9999 9999 9999"
  value={value}
  onChangeText={(text) => setValue(text)}
  placeholder="xxxx xxxx xxxx xxxx"
/>

This mask allows users to enter a 16-digit credit card number in a specific format.

Best Practices for Input Masks

When using input masks, keep the following best practices in mind:

1. Keep it simple: Avoid using complex masks that may confuse users.
2. Test thoroughly: Test your input masks with different inputs to ensure they work as expected.
3. Provide clear placeholders: Use clear and concise placeholders to help users understand the expected input format.