react-input-mask
Input masking component for React. Made with attention to UX.
This is a development branch for version 3.0. For the latest stable version see v2 branch.
Table of Contents
Installation
npm install --save mona-health/react-input-mask@alpha
react-input-mask v3 requires React 16.8.0 or later. If you need support for older versions, use version 2.
Usage
import React from 'react'
import InputMask from '@mona-health/react-input-mask'
function DateInput(props) {
return (
<InputMask
mask="99/99/9999"
onChange={props.onChange}
value={props.value}
/>
);
}
Properties
Name | Type | Default | Description |
---|
mask | {String|Array<String, RegExp>} | | Mask format |
maskPlaceholder | {String} | _ | Placeholder to cover unfilled parts of the mask |
alwaysShowMask | {Boolean} | false | Whether mask prefix and placeholder should be displayed when input is empty and has no focus |
beforeMaskedStateChange | {Function} | | Function to modify value and selection before applying mask |
children | {ReactElement} | | Custom render function for integration with other input components |
mask
Mask format. Can be either a string or array of characters and regular expressions.
<InputMask mask="99/99/99" />
Simple masks can be defined as strings. The following characters will define mask format:
Character | Allowed input |
---|
9 | 0-9 |
a | a-z, A-Z |
* | 0-9, a-z, A-Z |
Any format character can be escaped with a backslash.
More complex masks can be defined as an array of regular expressions and constant characters.
const firstLetter = /(?!.*[DFIOQU])[A-VXY]/i;
const letter = /(?!.*[DFIOQU])[A-Z]/i;
const digit = /[0-9]/;
const mask = [firstLetter, digit, letter, " ", digit, letter, digit];
return <InputMask mask={mask} />;
maskPlaceholder
<InputMask mask="99/99/99" maskPlaceholder="-" value="12" />
<InputMask mask="99/99/99" maskPlaceholder="dd/mm/yy" value="12" />
<InputMask mask="99/99/99" maskPlaceholder={null} value="12" />
Character or string to cover unfilled parts of the mask. Default character is "_". If set to null
or empty string, unfilled parts will be empty as in a regular input.
alwaysShowMask
If enabled, mask prefix and placeholder will be displayed even when input is empty and has no focus.
beforeMaskedStateChange
In case you need to customize masking behavior, you can provide beforeMaskedStateChange
function to change masked value and cursor position before it's applied to the input.
It receieves an object with previousState
, currentState
and nextState
properties. Each state is an object with value
and selection
properites where value
is a string and selection is an object containing start
and end
positions of the selection.
- previousState: Input state before change. Only defined on
change
event. - currentState: Current raw input state. Not defined during component render.
- nextState: Input state with applied mask. Contains
value
and selection
fields.
Selection positions will be null
if input isn't focused and during rendering.
beforeMaskedStateChange
must return a new state with value
and selection
.
function beforeMaskedStateChange({ nextState }) {
let { value } = nextState;
if (value.endsWith('/')) {
value = value.slice(0, -1);
}
return {
...nextState,
value
};
}
return (
<InputMask
mask="99/99/99"
maskPlaceholder={null}
beforeMaskedStateChange={beforeMaskedStateChange}
/>
);
Please note that beforeMaskedStateChange
executes more often than onChange
and must be pure.
children
To use another component instead of regular <input />
provide it as children. The following properties, if used, should always be defined on the InputMask
component itself: onChange
, onMouseDown
, onFocus
, onBlur
, value
, disabled
, readOnly
.
import React from 'react';
import InputMask from '@mona-health/react-input-mask';
import MaterialInput from '@material-ui/core/Input';
function Input(props) {
return (
<InputMask mask="99/99/9999" value={props.value} onChange={props.onChange}>
<MaterialInput type="tel" disableUnderline />
</InputMask>
);
}
function InvalidInput(props) {
return (
<InputMask mask="99/99/9999" value={props.value}>
<MaterialInput type="tel" disableUnderline onChange={props.onChange} />
</InputMask>
);
}
Caveat: To support both class and function component children InputMask used to use ReactDOM.findDOMNode
, which is now deprecated. To handle removing this, direct child class components are no longer supported. The children
component is now either:
-
a function component that implments React.forwardRef
const FunctionalInputComponent = React.forwardRef((props, ref) => {
return (
<input ref={ref} {...props} />
);
});
-
a class component that is wrapped in a function component that implements React.forwardRef
(innerRef
can be called anything as long as it's not ref
)
class InnerClassInputComponent extends React.Component {
render() {
const { innerRef, ...restProps } = this.props;
return (
<div>
<input ref={innerRef} {...restProps} />
</div>
);
}
}
const ClassInputComponent = React.forwardRef((props, ref) => {
return <InnerClassInputComponent innerRef={ref} {...props} />;
});
For more information see the Material UI Composition guide - caveat with Refs.
Known Issues
Autofill
Browser's autofill requires either empty value in input or value which exactly matches beginning of the autofilled value. I.e. autofilled value "+1 (555) 123-4567" will work with "+1" or "+1 (5", but won't work with "+1 (___) ___-____" or "1 (555)". There are several possible solutions:
- Set
maskPlaceholder
to null and trim space after "+1" with beforeMaskedStateChange
if no more digits are entered. - Apply mask only if value is not empty. In general, this is the most reliable solution because we can't be sure about formatting in autofilled value.
- Use less formatting in the mask.
Please note that it might lead to worse user experience (should I enter +1 if input is empty?). You should choose what's more important to your users — smooth typing experience or autofill. Phone and ZIP code inputs are very likely to be autofilled and it's a good idea to care about it, while security confirmation code in two-factor authorization shouldn't care about autofill at all.
Cypress tests
The following sequence could fail
cy.get('input')
.focus()
.type('12345')
.should('have.value', '12/34/5___');
Since focus is not an action command, it behaves differently than the real user interaction and, therefore, less reliable.
There is a few possible workarounds
cy.get('input')
.type('12345')
.should('have.value', '12/34/5___')
cy.get('input')
.click()
.type('12345')
.should('have.value', '12/34/5___')
cy.get('input')
.focus()
.wait(50)
.type('12345')
.should('have.value', '12/34/5___');
Building
Running npm install
runs lint
, test
, clean
and build
scripts too.
Set the CHROME_BIN
environment variable which is the path to the Chrome binary to prevent karma errors in npm run test
.
Thanks
Thanks to BrowserStack for the help with testing on real devices