react-var-ui is a simple React component library for variable setting and preview, inspired by iOS settings, react-dat-gui and dat.gui.

While some code from react-dat-gui was used, this library functions in a completely different way. The codebase uses modern React code practices such as hooks and functional components. Instead of iterating over the children array, react-var-ui uses a Context. Creation of custom components is also easier.

What makes react-var-ui different when compared to similar libraries such as Leva or react-dat-gui, react-var-ui doesn't force itself to float over all your content, instead react-var-ui lives peacefully inside of the React node it is placed in. Unlike Leva and much more like react-dat-gui, react-var-ui relies on a local state variable, providing the developer with more flexibility. While this might seem less convenient, it allows for more customization and usage of multiple instances of react-dat-gui within one project.

Table of contents

• Installation
• Example usage
• Testing
• Utility components
  • VarUI
  • VarCategory
  • VarArray
• Input components
  • Base properties
  • VarAngle
  • VarBase
  • VarButton
  • VarColor
  • VarDisplay
  • VarFile
  • VarImage
  • VarMedia
  • VarNumber
  • VarSelect
  • VarSlider
  • VarString
  • VarToggle
  • VarXY
• Theme customization
• Custom input components

Installation

Install react-var-ui with either npm or yarn:

yarn add react-var-ui
# or
npm install react-var-ui

Then include the CSS with:

/* In your CSS/SCSS file: */
@import 'react-var-ui/index.css';

or:

// In your JS/TS file (assuming your bundler supports loading CSS files):
import 'react-var-ui/index.css';

Example usage

const [values, setValues] = React.useState({
  toggle: true,
  color: '#FF0000',
  select: 1,
  slider: 0.4,
  xy: [0, 0.2],
  string: 'Hello world!',
});

return (
  <VarUI onChange={setValues} values={values}>
    <VarCategory label="Example">
      <VarColor path="color" label="Color" />
      <VarToggle path="toggle" label="Toggle" />
      <VarSelect
        path="select"
        label="Select"
        options={[
          { key: 0, label: 'Zero' },
          { key: 1, label: 'One' },
        ]}
      />
      <VarSlider
        label="VarSlider"
        path="slider"
        min={0.2}
        max={0.8}
        step={0.1}
      />
      <VarString label="VarString" path="string" />
      <VarXY label="VarXY" path="xy" />
      <VarButton buttonLabel="VarButton" onClick={() => alert('clicked!')} />
    </VarCategory>
  </VarUI>
);

Testing

react-var-ui uses jest for automated unit tests and storybook for manually testing the UI.

You can run unit tests after installing by running:

yarn test

Storybook can be ran with:

yarn storybook

To run the example app, you first need to start the project with:

yarn start

And then enter the example directory and start the app:

cd ./example
yarn start

(make sure to run yarn install before.)

Utility components

<VarUI />

This is the main component which provides a Context for other components. It is not required to use this component - other components accept onChange and value properties which provide a similar functionality.

Required properties

Property	Description	Type
values	A JavaScript object or array to be mutated by the input components.	object
onChange	The function to be called with the entire changed object.	(values: object) => void
onChangeValue	The function to be called when one value is changed.	(path: string, newValue: any) => void

Optional properties

Property	Description	Type
className	Additional class names for the wrapper object.	string

<VarCategory />

Category component for grouping inputs.

Required properties

Property	Description	Type
label	Category label.	ReactNode

Optional properties

Property	Description	Type
className	Additional class names on the wrapping div element.	string
collapsible	Should display the Collapse/Expand button.	boolean

<VarArray />

Renders an array value as a list of elements.

Optional properties

Property	Description	Type
className	Additional class names on the wrapping div element.	string
disabled	Should the component and its children be disabled.	boolean
children	Renders children with the array element as its context.	ReactNode | (element: T, index: number, array: T[]) => ReactNode

<VarScope />

Creates a context with a certain path as base.

Optional properties

Property	Description	Type
path	Path to use as the base path.	string

Examples

With ReactNode children:

<VarUI values={{ test: [{ prop: 'a' }, { prop: 'b' }, { prop: 'c' }] }}>
  <VarArray path="test">
    <VarInput path="prop" label="Example" />
  </VarArray>
</VarUI>

With function:

<VarUI values={{ test: [{ prop: 'a' }, { prop: 'b' }, { prop: 'c' }] }}>
  <VarArray path="test">
    {(element, index) => <VarInput path="prop" label={`Element: ${index}`} />}
  </VarArray>
</VarUI>

Input components

Base properties

Most input components accept the following base properties.

Does not apply to <VarButton />.

Optional properties

T is component's value type.

Property	Description	Type
label	Label to be shown left to the input.	ReactNode
className	Additional class names on the wrapping div element.	string
path	Variable path in the data object.	string
value	Current value (only used if context and path aren't available). In most cases you aren't going to need this.	T
defaultValue	Default value for components that support resetting (on double click for example).	T
disabled	Should the component be disabled.	boolean
readOnly	Should the component be read-only.	boolean
onChange	On change event, called with the new value if provided. In most cases you aren't going to need this.	(value: T) => void
children	Children. Only rendered when provided directly to the VarBase component.	ReactNode

<VarAngle />

Angle picker component. Accepts and provides numbers (radians).

T = number (rad)

<VarBase />

Base VarUI input component. Doesn't do anything besides displaying the label.

Used to construct other components from.

<VarButton />

Button component.

Does not accept any of the base component properties.

Required properties

Property	Description	Type
buttonLabel	Category label.	ReactNode

Optional properties

Property	Description	Type
onClick	Called when the button is clicked.	() => void
disabled	Should the component be disabled.	boolean

<VarColor />

Color picker component. Returns and accepts values in form of hex color strings.

Uses @uiw/react-color-sketch to render the color picker.

T = string (#XXXXXX)

Optional properties

Property	Description	Type
alpha	Should allow picking alpha values? If true, the result hex code will contain extra two characters representing the alpha value, from 00 to FF.	boolean

<VarDisplay />

A simple component that displays a string or a numeric value.

Only accepts path and value. Does not change any values.

T = string | number

<VarFile />

A simple file input component. Accepts and provides File instances.

T = File

Optional properties

Property	Description	Type
accept	List of accepted file types.	string
displayMetadata	Whether file information should be displayed in the field. (default: true)	boolean

<VarImage />

A simple image input component. Accepts and provides blob/data URLs.

T = string

<VarMedia />

Media (audio/video/image) input component. Accepts and provides a blob URL.

If acceptImage, acceptAudio and acceptVideo are all false, the component will accept all 3.

T = string

Optional properties

Property	Description	Type
acceptImage	Whether the component should accept image/* files.	boolean
acceptAudio	Whether the component should accept audio/* files.	boolean
acceptVideo	Whether the component should accept video/* files.	boolean

<VarNumber />

Integer/float number component. Accepts and provides numbers.

T = number

Optional properties

Property	Description	Type
min	Minimum value.	number
max	Maximum value.	number
step	Step.	number
integer	Should the end result be rounded to an integer value.	boolean
showInput	If true will display an editable input, otherwise shows a read only value.	boolean
showButtons	If true will display buttons that increase and decrease the value by step.	boolean

<VarSelect />

Select component. Returns and accepts either value from option object or key when value is not provided.

T = any

Required properties

Property	Description	Type
options	Options to be displayed.	IVarSelectOption[]

Interface: IVarSelectOption

Required:

Property	Description	Type
key	Key for the option. Also used as value if value is not specified.	ReactText
label	Option label.	string

Optional:

Property	Description	Type
value	Option value. Key will be used if not specified. Note: Will be serialized to JSON and deserialized when selected.	any

<VarSlider />

Integer/float slider component. Accepts and provides numbers.

T = number

Required properties

Property	Description	Type
min	Minimum value.	number
max	Maximum value.	number
step	Step.	number

Optional properties

Property	Description	Type
integer	Should the end result be rounded to an integer value.	boolean
showInput	If true will display an editable input, otherwise shows a read only value.	boolean
showButtons	If true will display buttons that increase and decrease the value by step.	boolean

<VarString />

String input component. Accepts and provides a string value.

T = string

Optional properties

Property	Description	Type
maxLength	Maximum length of the text.	number
multiline	Should the field be a textarea?	boolean

<VarToggle />

Checkbox/toggle component. Accepts and returns a boolean (true/false).

T = boolean

<VarXY />

XY offset picker. Accepts and provides an array in form of [x, y].

T = [number (x), number (y)]

Optional properties

Property	Description	Type
min	Minimum value.	[number (x), number (y)]
max	Maximum value.	[number (x), number (y)]
step	Step.	[number (x), number (y)]

Theme customization

The colors can be customized as such (provided are default values):

.react-var-ui {
  /* Foreground color, used for text. */
  --react-var-ui-foreground-color: #ddd;

  /* Background color, used for category header backgrounds. */
  --react-var-ui-background-color: #11111a;

  /* Accent color, used for active parts of sliders, toggles and XY. */
  --react-var-ui-accent-color: #77f;

  /* Input background color. */
  --react-var-ui-input-background-color: #353542;

  /* Input background color (when hovered). */
  --react-var-ui-input-background-hover-color: #424253;

  /* Input background color (when pressed). Only applies to buttons. */
  --react-var-ui-input-background-pressed-color: #2b2b37;

  /* Label background color. */
  --react-var-ui-label-background-normal-color: #22222a;

  /* Label background color (when hovered). */
  --react-var-ui-label-background-hover-color: #2a2a33;

  /* Label border color. */
  --react-var-ui-label-border-color: #33333a;
}

Custom input components

react-var-ui provides a <VarBase /> component and a useVarUIValue hook designed to facilitate creation of custom components.

Example usage

import React from 'react';
import { useVarUIValue, IVarBaseInputProps, VarBase } from 'react-var-ui';

// Please specify the <T>.
export interface IVarCustomProps extends IVarBaseInputProps<string> {}

/**
 * Custom input component. In this example, it's a simple text input.
 */
export const VarCustom = ({
  label,
  path,
  value,
  onChange,
  disabled,
  className,
}: IVarCustomProps): JSX.Element => {
  /**
   * currentValue will contain the current value from the value object
   * (at a given path) or value from properties if that's not available.
   *
   * setCurrentValue will set the value onto a given path in the object
   * and call onChange if available.
   *
   * All arguments are optional, path/object-based value changes take
   * precedence.
   */
  const [currentValue, setCurrentValue] = useVarUIValue(path, value, onChange);

  /**
   * We're wrapping our component in VarBase which provides the default
   * label.
   *
   * It is necessary to wrap what should appear on the right in a <span>.
   * If this behavior is undesired, a <div> with grid-column: 1 / 3; can
   * be used.
   */
  return (
    <VarBase label={label} disabled={disabled} className={className}>
      <span>
        <input
          type="text"
          maxLength={maxLength}
          value={currentValue}
          onChange={e => setCurrentValue(e.target.value)}
        />
      </span>
    </VarBase>
  );
};