react-numeric-input

React Numeric Input

Number input component that can replace the native number input which is not yet very well supported and where it is, it does not have the same appearance across the browsers. Additionally this component offers more flexible options and can be used for any values (differently formatted representations of the internal numeric value).

Live demo

Installation

npm install react-numeric-input --save

Then in your scripts:

// es6
import NumericInput from 'react-numeric-input';
// or es5
var NumericInput = require('react-numeric-input');
// or TypeScript
import * as NumericInput from "react-numeric-input";

Usage

Minimal Usage:

This will behave exactly like <input type="number">. It will create an empty numeric input that starts changing from zero. The difference that this works on any browser and does have the same appearance on each browser.

<NumericInput/>
// or:
<NumericInput className="form-control"/>

Typical Usage

Most of the time you will need to specify min, max and value:

<NumericInput min={0} max={100} value={50}/>

Working with floats

You can use step and precision props to make your input working with floating point numbers:

<NumericInput step={0.1} precision={2} value={50.3}/>

Snap to step

If you want your component to "snap" to the closest step value while incrementing or decrementing (up/down buttons or arrow keys) you can use the snap prop:

<NumericInput step={0.5} precision={2} value={50.3} snap/>

Custom format

By default the component displays the value number as is. However, you can provide your own format function that will be called with the numeric value and is expected to return the string that will be rendered in the input:

function myFormat(num) {
    return num + '$';
}
<NumericInput precision={2} value={50.3} step={0.1} format={myFormat}/>

Please note that the example above is fine but in most situations if you have custom format function you will also need to provide custom parse function that is able to convert whatever the format returns back to numeric value. In the example above the built-in parse function will strip the "$" suffix because internally it uses parseFloat. However, if the format function was returning "$" + num, then the parse function should do something like:

function parse(stringValue) {
    return stringValue.replace(/^\$/, "");
}

Props

Name	Type	Default
value	number or string	"" which converts to 0
min	number or function	Number.MIN_SAFE_INTEGER
max	number or function	Number.MAX_SAFE_INTEGER
step	number or function	1
precision	number or function	0
parse	function	parseFloat
format	function	none
className	string	none
disabled	boolean	none
readOnly	boolean	none
style	object or false	none
size	number or string	none
mobile	true, false, 'auto' or function	auto
snap	boolean	none (false)
componentClass	string	input

Any other option is passed directly the input created by the component. Just don't forget to camelCase the attributes. For example readonly must be readOnly. See examples/index.html for examples.

Event Callbacks

You can pass callback props like onClick, onMouseOver etc. and they will be attached to the input element and React will call them with null scope and the corresponding event. However, there are few special cases to be aware of:

• onChange - Called with valueAsNumber, valueAsString and the input element. The valueAsNumber represents the internal numeric value while valueAsString is the same as the input value and might be completely different from the numeric one if custom formatting is used.
• onInvalid - Will be called with errorMessage, valueAsNumber and valueAsString.
• onValid - There is no corresponding event in browsers. It will be called when the component transitions from invalid to valid state with the same arguments as onChange: valueAsNumber and valueAsString.

Styling

The component uses inline styles which you can customize. The style prop is not added directly to the component but instead it is a container for styles which you can overwrite. For example

<NumericInput style={{
	input: {
		color: 'red'
	}
}}>

You can modify the styles for everything including states like :hover, :active and :disabled. Take a look at the source to see what styles are supported. Also, the style is stored as static class property so that you can change it and affect all the components from your script. Example:

import NumericInput from 'react-numeric-input';
NumericInput.style.input.color = 'red';

Finally, you can still use CSS if you want. Each component's root element has the react-numeric-input class so that it is easy to find these widgets on the page. However, keep in mind that because of the inline styles you might need to use !important for some rules unless you pass style={false} which will disable the inline styles and you will have to provide your own CSS styles for everything. Example:

.react-numeric-input input {
	color: red;
}

Keyboard navigation

• You can use ⬆ and ⬇ arrow keys to increment/decrement the input value.
• Ctrl + ⬆ or ⌘ + ⬆ and Ctrl + ⬇ or ⌘ + ⬇ to use smaller step (step / 10). Note that this will only work if you have specified a precision option that supports it.
• Shift + ⬆ and Shift + ⬇ to use bigger step (step * 10).

Integration with external scripts

This component aims to provide good integration not only with React but with any third party script that might want to work with it on the current page.

getValueAsNumber()

The native number inputs have special property called valueAsNumber. It provides access to the value as number to be used by scripts. In this react component this becomes even more desirable as the display value might be formatted and have nothing in common with the underlying value meaning that one might need to call parse to find out what the numeric value is. For that reason this component exposes getValueAsNumber() method on the input element. Also keep in mind that this really returns a number (float) so it might be different from the displayed value. For example an input showing "12.30" will have getValueAsNumber() returning 12.3 and if the input is empty the result would be 0.

setValue()

An external script that does not "understand" React can still work with this component by reading the getValueAsNumber() or by calling the setValue() method exposed on the input element. Here is an example with jQuery:

$('input[name="some-input"]')[0].setValue('123mph');

Calling this method will invoke the component's parse method with the provided argument and then it will setState causing the usual re-rendering.

function props

In rare cases it might be better to "decide" what the value of certain prop is at runtime without having to through the entire ceremony of redux, flux, or whatever will make your component to be re-rendered with other props. For example one might want to have a variable step prop based on the current input value and the change direction:

<NumericInput step={(component, direction) => {
	// for values smaller than 10 the step is 0.1
	// for values greater than 10 the step is 0.01
	return component.state.value < 10 ? 0.1 : 0.01

	// or have different step depending on the direction
	return direction === NumericInput.DIRECTION_UP ? 0.01 : 0.1;

	// or just obtain it from somewhere
	return window.outerWidth % 100 + 1;
}}>

The props that support being a function are currently min, max, step and precision. All those function will be passed the component instance as argument and the step will also receive the direction as second parameter.

License

MIT