@ringpublishing/mui-theme

Package includes Ring Publishing theme for MUI components.

Typography units – rem (default) vs deprecated-px

Starting from version 4.3.0, the default typography uses standard rem units (1rem = 16px, browser default). This improves accessibility – components scale with the user's browser font size settings.

If you are upgrading from an earlier version and your project includes the legacy CSS hack:

html {
    font-size: 62.5%;
}

you have two options:

Option A – Migrate to rem (recommended)

1. Remove html { font-size: 62.5%; } from your global CSS.
2. Review any custom styles that used rem values assuming 1rem = 10px and convert them (multiply by 0.625, e.g. 2.4rem → 1.5rem).
3. Use the default <ThemeConfig> without any extra prop.

Option B – Stay on deprecated-px mode

Use the typographyMode="deprecated-px" prop to keep the previous px-based typography and remain compatible with the html { font-size: 62.5%; } setup:

<ThemeConfig mode="light" typographyMode="deprecated-px">
    <App />
</ThemeConfig>

⚠️ typographyMode="deprecated-px" is deprecated and will be removed in the next major version. It is intended as a temporary bridge to allow gradual migration.

Version 4.x.x supports:

• "@emotion/styled": "^11.0.0"
• "@mui/material": "^7.0.0"
• "@mui/x-data-grid": "^8.0.0"
• "@mui/x-data-grid-pro": "^8.0.0"
• "@mui/x-date-pickers": "^8.0.0"
• "@mui/x-date-pickers-pro": "^8.0.0"

Installation

npm install @ringpublishing/mui-theme

Minimal usage example

import { TablePagination } from '@mui/material';
import { ThemeConfig } from '@ringpublishing/mui-theme';

function App() {
    return (
        <ThemeConfig mode="light">
            <TablePagination
                count={2000}
                rowsPerPage={10}
                page={1}
                component="div"
                onPageChange={() => {
                    //
                }}
            />
        </ThemeConfig>
    );
}

With language and custom locales

Note: default language is 'enUS' and it works 'out of the box'. If you want to support other locales, follow example below.

PL locales for MUI core also are available. Just set language to 'plPL'.

import { TablePagination } from '@mui/material';
import { zhCN } from '@mui/material/locale';
import { plPL as xDataGridPl } from '@mui/x-data-grid/locales';
import { ThemeConfig } from '@ringpublishing/mui-theme';

function App() {
    return (
        <ThemeConfig mode="light" language="plPL" externalLocales={[xDataGridPl, zhCN]}>
            <TablePagination
                count={2000}
                rowsPerPage={10}
                page={1}
                component="div"
                onPageChange={() => {
                    //
                }}
            />
        </ThemeConfig>
    );
}

Theme overrides

Use themeOverrides to customize palette, typography, spacing, breakpoints, shape, and components.

import { ThemeConfig } from '@ringpublishing/mui-theme';

function App() {
    return (
        <ThemeConfig
            mode="light"
            themeOverrides={{
                palette: {
                    primary: { main: '#FF5733' }
                },
                typography: {
                    h1: { fontSize: '4rem' }
                },
                spacing: 4,
                shape: { borderRadius: 16 },
                components: {
                    MuiButton: {
                        defaultProps: { variant: 'outlined' },
                        styleOverrides: {
                            root: { borderRadius: 8 }
                        }
                    }
                }
            }}
        >
            <App />
        </ThemeConfig>
    );
}

Component styleOverrides merge behavior

When overriding components, styleOverrides merge depends on the value type:

Library default	Your override	Result
object	object	Deep merge — your CSS keys override, rest preserved
function	function	Last-wins — your function replaces library default entirely
function	object	Replacement — your object wins
object	function	Replacement — your function wins

Object-valued overrides safely merge CSS properties:

// Library default: fontSize: '10px', fontWeight: '400', lineHeight: '14px'
// Your override:
themeOverrides={{
    components: {
        MuiTooltip: {
            styleOverrides: {
                tooltip: {
                    fontSize: '14px',  // overrides default 10px
                    color: 'red'       // added — fontWeight and lineHeight preserved
                }
            }
        }
    }
}}

Function-valued overrides replace the library default completely — you must include all styles you need:

// Library default for MuiAccordion root is a function with backgroundColor, minHeight, margin
// Your override must repeat any styles you want to keep:
themeOverrides={{
    components: {
        MuiAccordion: {
            styleOverrides: {
                root: ({ theme }) => ({
                    backgroundColor: theme.palette.grey[100],
                    minHeight: theme.spacing(4),  // must repeat — library default is lost
                    margin: 0                      // must repeat — library default is lost
                })
            }
        }
    }
}}

Deep merge example

Below is a full input/output example showing how createTheme(base, overrides) merges component definitions.

Library defaults (base):

components: {
    MuiTooltip: {
        styleOverrides: {
            tooltip: { fontSize: '10px', fontWeight: '400', lineHeight: '14px' }
        }
    },
    MuiTextField: {
        defaultProps: { variant: 'standard' }
    },
    MuiChip: {
        defaultProps: { size: 'small' }
    }
}

Your overrides:

themeOverrides={{
    components: {
        MuiTooltip: {
            styleOverrides: {
                tooltip: { fontSize: '14px', color: 'red' }
            }
        },
        MuiTextField: {
            defaultProps: { variant: 'outlined', size: 'small' }
        },
        MuiButton: {
            defaultProps: { variant: 'contained' }
        }
    }
}}

Result after merge:

components: {
    // Deep merged — fontSize overridden, color added, fontWeight and lineHeight preserved
    MuiTooltip: {
        styleOverrides: {
            tooltip: { fontSize: '14px', fontWeight: '400', lineHeight: '14px', color: 'red' }
        }
    },
    // Deep merged — variant overridden to 'outlined', size added
    MuiTextField: {
        defaultProps: { variant: 'outlined', size: 'small' }
    },
    // Untouched — no override provided
    MuiChip: {
        defaultProps: { size: 'small' }
    },
    // Added — new component not in base
    MuiButton: {
        defaultProps: { variant: 'contained' }
    }
}

Using getTheme directly

If you need the theme object without ThemeConfig (e.g. for a custom ThemeProvider, SSR, or tests), use getTheme with an options object:

import { ThemeProvider } from '@mui/material';
import { getTheme } from '@ringpublishing/mui-theme';

function App() {
    const theme = getTheme('light', {
        language: 'plPL',
        themeOverrides: {
            palette: { primary: { main: '#FF5733' } }
        }
    });

    return (
        <ThemeProvider theme={theme}>
            <MyApp />
        </ThemeProvider>
    );
}

getTheme options

getTheme(mode: 'light' | 'dark', options?: GetThemeOptions): Theme

Option	Type	Default	Description
language	CommonLanguages | string	'enUS'	Locale for MUI core translations
externalLocales	object[]	[]	Additional MUI locale objects (e.g. xDataGridPl)
themeOverrides	ThemeOverrides	{}	Deep merge overrides for palette, typography, spacing, breakpoints, shape, components
typographyMode	'rem' | 'deprecated-px'	'rem'	Typography unit mode. 'deprecated-px' is deprecated
externalComponentsTheme	object	{}	Deprecated — use themeOverrides.components
externalColors	object	{}	Deprecated — use themeOverrides.palette

Examples

// Minimal
const theme = getTheme('light');

// With language
const theme = getTheme('dark', { language: 'plPL' });

// With typography mode for legacy projects using html { font-size: 62.5% }
const theme = getTheme('light', { typographyMode: 'deprecated-px' });

// With theme overrides
const theme = getTheme('light', {
    language: 'plPL',
    themeOverrides: {
        palette: { primary: { main: '#FF5733' } },
        spacing: 4,
        components: {
            MuiButton: { defaultProps: { variant: 'outlined' } }
        }
    }
});

// With external locales
const theme = getTheme('light', {
    language: 'plPL',
    externalLocales: [xDataGridPl, zhCN]
});

Migration from positional arguments: The old positional signature getTheme(mode, language, externalComponentsTheme, externalLocales, externalColors, themeOverrides, typographyMode) is deprecated and logs a console warning. See ADR-001 for migration details and before/after examples.

With custom components theme fragment (deprecated)

Deprecated: Use themeOverrides.components instead. The externalComponentsTheme prop uses spread (...) which silently drops your overrides for components already defined in the library.

import { TablePagination } from '@mui/material';
import { ThemeConfig } from '@ringpublishing/mui-theme';

function App() {
    const MuiDataGridPart = {
        components: {
            MuiDataGrid: {
                styleOverrides: {
                    root: {
                        backgroundColor: 'red'
                    }
                }
            }
        }
    };

    return (
        <ThemeConfig mode="light" externalComponentsTheme={MuiDataGridPart}>
            <TablePagination
                count={2000}
                rowsPerPage={10}
                page={1}
                component="div"
                onPageChange={() => {
                    //
                }}
            />
        </ThemeConfig>
    );
}