TypeScript icon, indicating that this package has built-in type declarations

4.2.9 • Public • Published

React Modifier

ReactModifier is a tool that can help you to customize app. Main idea - many themes, one component.


npm npm npm npm

This package can:

  • Mix modifiers
  • Modify component head to position it
  • Modify whole component to apply a theme

What's the problem?

How many component's visual style can you modify without changing its code? The value is low I bet.

An example of typical situation

const TestC = (
    <div classname="test">
        <div className="test__block">
            <span className="test__text">Text</span>

const App = (
    <div classname="app">
        <TestC />

Can't add theme or change position for inner elements. Obviously you can't reuse that component. If you're going to position it editing original component, you position it everywhere.

Can we solve the problem? Actually we can. There is 2 ways:

  1. Create wrapper with class, that modifies nested elements
  2. Create component, that receives modifiers props, and returns modified version.

Solved example:

// first method
const App = (
    <div classname="app">
        {/* unwanted structure */} 
        <div className="app__testc">
            <TestC />

// second method
const mod = { className: "app__testc" };

const App = (
    {/* all good */} 
    <div classname="app">
        <TestC mod={mod} />

This package using second way.


📦 To download this package from npm paste this command in a terminal

npm install react-modifier

How to use

First of all you have to import the library.

import * as RM from "react-modifier";
// OR you can import individual functions and interfaces
// import { IModifiableProps, IModifiableTheme, IModifier, createMod, mixMod, modElement} from "react-modifier";

Then you can create customizable functional or class components

Functional component example

// define theme & props interfaces
export interface FlexAppTheme extends IModifiableTheme {
    textMod: IModifier;

export interface IFlexAppProps extends IModifiableProps<FlexAppTheme> {
    text: string;

export const FlexAppF: FunctionComponent<IFlexAppProps> = (props: IFlexAppProps) => {
    const { text, theme, mod } = props;
    const headMod = getHeadModByProps(props);

    return modElement((
        <div className="app">
                <span className="app__text">
            ), theme.textMod)}
    ), headMod);

// theme instances
const defaultTheme: FlexAppTheme = {
    head: createMod(""),
    textMod: createMod("")

const darkTheme: FlexAppTheme = {
    head: createMod("app_dark"),
    textMod: createMod("app__text_dark")

// all themes
export const flexAppThemes = {
    dark: darkTheme,
    default: defaultTheme

Class component

Just import IModifiableComponent class.

export class FlexApp extends IModifiableComponent<FlexAppTheme, IFlexAppProps> {
    constructor(props: IFlexAppProps) {

    renderThemed() {
        <div className="app">
                <span className="app__text">
            ), this.theme.textMod)}

// also it's possible to pass third type or interface, that describes State
// <FlexAppTheme, IFlexAppProps, IFlexAppState>

Okay, now we can use the new component. A Theme prop is required, but mod is optional, you always can define default theme in component to reuse it.

FlexAppF text="It actually works" mod={createMod("root__app")} theme={flexAppThemes.dark}></FlexAppF>

The result will be

    <div class="app root__app app_dark">
        <span class="app__text app__text_dark">It actually works</span>


Let's take a look how does it work

Modifier is just an interface, that haves className and id properties;

interface IModifier {
    className: string;
    id: string;

    // if you want to modify more props, fork my github repo

createMod function wraps your args to new IModifier obj

// createMod(className?, id?);
createMod("mod_class", "mod-el");

mixModifier function combining all classNames to one and takes first id

mixModifiers(mod, mod2, mod3...) => IModifier;

modElement function applies mod on provided element and

returns modified version

modElement(element: ReactElement, mod: IModifier): ReactElement;

IModifiableProps is an interface that haves theme and head mod

interface IModifiableProps<T> {
    theme: T; // head && body modifiers
    mod?: IModifier; // component head modifier
    inputMod: IModifier; // custom mod

// extend that interface to add other props

IModifiableTheme contains head mod

interface IModifiableTheme {
    head: IModifier;

// extend that interface to add other customizable parts

IModifiableComponent class has constructor with modifer props & renderThemedMethod

// pass your own Theme & Props interface realization
class IModifiableComponent<Theme: IModifiableTheme, Props: IModifiableProps, State?> extends React.Component {
    renderThemed(): ReactElement; 
    // Return elements here, but don't modify first element! 
    // It's already doing render method. 

Enjoy this package

Package Sidebar


npm i react-modifier

Weekly Downloads





GNU General Public License, version 2

Unpacked Size

231 kB

Total Files


Last publish


  • kostayne