typescript-styled-components-px2rem
TypeScript transformer for convert px
to rem
units of styled-components
-
Use postcss-plugin-px2rem to process all css text in template strings.
-
Add a runtime px2rem
function polyfill to process expression embedded in template strings when enable transformRuntime option.
Babel plugin with similar functionality:babel-plugin-styled-components-px2rem.
Table of Contents
Requirement
You need to install the following peerDependencies
of typescript-styled-components-px2rem into your project at the same time:
{
"peerDependencies": {
"typescript": "^3.0.0",
"postcss": "^7.0.0"
}
}
Usage
see example
The use of React and styled-components test cases.
Integration with rollup-plugin-typescript2 and ttypescript:
import typescript2 from 'rollup-plugin-typescript2';
import tts from 'ttypescript';
export default {
plugins: [
typescript2({
typescript: tts,
objectHashIgnoreUnknownHack: true,
tsconfigOverride: {
compilerOptions: {
module: 'ES2015',
plugins: [
{
transform: 'typescript-styled-components-px2rem',
rootValue: 100,
unitPrecision: 5,
minPixelValue: 0,
multiplier: 1,
tags: ['styled', 'css', 'createGlobalStyle', 'keyframes'],
transformRuntime: false,
},
],
},
},
}),
],
};
Integration with awesome-typescript-loader or ts-loader:
const createCustomTransformer = require('typescript-styled-components-px2rem').default;
const customTransformer = createCustomTransformer({
rootValue: 100,
unitPrecision: 5,
minPixelValue: 0,
multiplier: 1,
tags: ['styled', 'css', 'createGlobalStyle', 'keyframes'],
transformRuntime: false,
});
module.exports = {
module: {
rules: [
{
test: /\.tsx?$/,
loader: 'ts-loader',
options: {
getCustomTransformers: () => ({ before: [customTransformer] }),
},
},
],
},
};
Integration with ts-jest and ttypescript:
jest.config.js:
module.exports = {
globals: {
'ts-jest': {
compiler: 'ttypescript',
},
},
};
tsconfig.json:
{
"compilerOptions": {
"plugins": [
{
"transform": "typescript-styled-components-px2rem",
"type": "config",
"rootValue": 100,
"unitPrecision": 5,
"minPixelValue": 0,
"multiplier": 1,
"tags": ["styled", "css", "createGlobalStyle", "keyframes"],
"transformRuntime": false
}
]
}
}
Composition
It should be put before typescript-plugin-styled-components
tsconfig.json:
{
"compilerOptions": {
"plugins": [
{
"transform": "typescript-styled-components-px2rem",
"type": "config"
},
{
"transform": "typescript-plugin-styled-components",
"type": "config"
}
]
}
}
Options
name |
type |
required |
default |
description |
rootValue |
number |
false |
100 |
The root element font size |
unitPrecision |
number |
false |
5 |
The decimal numbers to allow the REM units to grow to |
minPixelValue |
number |
false |
0 |
Set the minimum pixel value to replace |
multiplier |
number |
false |
1 |
The multiplier of input value |
tags |
string[] |
false |
["styled", "css", "createGlobalStyle", "keyframes"] |
styled-components template literal tagged |
transformRuntime |
boolean |
false |
false |
since 1.1.0,enable transformation of all expressions that embedded in template strings |
Simple version of the formula:
const input = '32px';
const pixels = parseFloat(input);
if (pixels < minPixelValue) {
return input;
}
const fixedVal = toFixed((pixels * multiplier) / rootValue, unitPrecision);
return `${fixedVal}rem`;
Remaining options are consistent with postcss-plugin-px2rem.
Transform Runtime
If enabled transformRuntime
option, all supported expressions embedded in template strings are processed as follows:
Note: Only expression that end with px
will be processed.
FunctionExpression
source code:
import styled from 'styled-components';
export const FunctionExpression = styled.button<{ width?: number | string }>`
width: ${function(props) {
return props.width;
}}px; /* Block Body */
${props => (props.disabled ? 'height: 400px' : 'height: 200px')};
`;
compiled:
import styled from 'styled-components';
export const FunctionExpression = styled.button`
width: ${(...args) =>
px2rem_1(function(props) {
return props.width;
}, ...args)}; /* Block Body */
${props => (props.disabled ? 'height: 4rem' : 'height: 2rem')};
`;
function px2rem_1(input, ...args) {
if (typeof input === 'function') return px2rem_1(input(...args), ...args);
var value = parseFloat(input);
var pixels = Number.isNaN(value) ? 0 : value;
if (Math.abs(pixels) < 0) return `${pixels}px`;
var multiplier = Math.pow(10, 5 + 1);
var wholeNumber = Math.floor(((pixels * 1) / 100) * multiplier);
return `${(Math.round(wholeNumber / 10) * 10) / multiplier}rem`;
}
ArrowFunctionExpression
source code:
import styled from 'styled-components';
const height = '44';
export const ArrowFunction = styled.input.attrs(props => ({
type: 'password',
size: props.size || '16px',
width: props.width || 100,
}))`
color: palevioletred;
font-size: 14px;
border: 1px solid palevioletred;
border-radius: 8px;
width: ${props => props.width}px; /* PropertyAccess Body */
height: ${() => height}px; /* Identifier Body */
line-height: ${() => '44'}px; /* StringLiteral Body */
margin: ${() => 32}px; /* NumericLiteral Body */
padding: ${props => props.size};
`;
export const ArrowFunctionWithBlockBody = styled.button<{ width?: number | string }>`
width: ${props => {
if (props.width) {
return props.width;
} else {
return 0;
}
}}px; /* Block Body */
${props => (props.disabled ? 'height: 400px' : 'height: 200px')};
`;
export const ArrowFunctionWithBinaryBody = styled.button<{ height?: number }>`
${props =>
props.disabled &&
`
width: 200px;
font-size: 14px;
`};
height: ${props => !props.disabled && props.height}px; /* Binary Body */
`;
export const ArrowFunctionWithConditionalBody = styled.button<{ height?: number }>`
height: ${props => (props.height ? height : 100)}px; /* Conditional Body */
`;
compiled:
import styled from 'styled-components';
const height = '44';
export const ArrowFunction = styled.input.attrs(props => ({
type: 'password',
size: props.size || '0.16rem',
width: props.width || 100,
}))`
color: palevioletred;
font-size: 0.14rem;
border: 1px solid palevioletred;
border-radius: 0.08rem;
width: ${props => px2rem_1(props.width)}; /* PropertyAccess Body */
height: ${() => px2rem_1(height)}; /* Identifier Body */
line-height: ${() => px2rem_1('44')}; /* StringLiteral Body */
margin: ${() => px2rem_1(32)}; /* NumericLiteral Body */
padding: ${props => props.size};
`;
export const ArrowFunctionWithBlockBody = styled.button`
width: ${props =>
px2rem_1(() => {
if (props.width) {
return props.width;
} else {
return 0;
}
})}; /* Block Body */
${props => (props.disabled ? 'height: 4rem' : 'height: 2rem')};
`;
export const ArrowFunctionWithBinaryBody = styled.button`
${props =>
props.disabled &&
`
width: 2rem;
font-size: 0.14rem;
`};
height: ${props => px2rem_1(!props.disabled && props.height)}; /* Binary Body */
`;
export const ArrowFunctionWithConditionalBody = styled.button`
height: ${props => (props.height ? px2rem_1(height) : px2rem_1(100))}; /* Conditional Body */
`;
function px2rem_1(input, ...args) {
if (typeof input === 'function') return px2rem_1(input(...args), ...args);
var value = parseFloat(input);
var pixels = Number.isNaN(value) ? 0 : value;
if (Math.abs(pixels) < 0) return `${pixels}px`;
var multiplier = Math.pow(10, 5 + 1);
var wholeNumber = Math.floor(((pixels * 1) / 100) * multiplier);
return `${(Math.round(wholeNumber / 10) * 10) / multiplier}rem`;
}
PropertyAccessExpression
source code:
import styled from 'styled-components';
export const PropertyAccessExpression = styled.button<{ width: number; height: string }>(
props => `
width: ${props.width}px;
height: ${props.height}; /* Note: Only expression end with 'px' will be processed. */
`,
);
compiled:
import styled from 'styled-components';
export const PropertyAccessExpression = styled.button(
props => `
width: ${px2rem_1(props.width)};
height: ${props.height}; /* Note: Only expression end with 'px' will be processed. */
`,
);
function px2rem_1(input, ...args) {
if (typeof input === 'function') return px2rem_1(input(...args), ...args);
var value = parseFloat(input);
var pixels = Number.isNaN(value) ? 0 : value;
if (Math.abs(pixels) < 0) return `${pixels}px`;
var multiplier = Math.pow(10, 5 + 1);
var wholeNumber = Math.floor(((pixels * 1) / 100) * multiplier);
return `${(Math.round(wholeNumber / 10) * 10) / multiplier}rem`;
}
ConditionalExpression
source code:
import React from 'react';
import styled from 'styled-components';
export const ConditionalExpression = function({ fontSize }: { fontSize?: unknown }) {
const StyledButton = styled.button`
font-size: ${typeof fontSize === 'number' ? fontSize : props => props?.theme.fontSize}px;
`;
return <StyledButton />;
};
export const ConditionalExpressionWhenTrue = function({ fontSize }: { fontSize?: unknown }) {
const StyledButton = styled.button`
font-size: ${typeof fontSize !== 'number' ? props => props?.theme.fontSize : fontSize}px;
`;
return <StyledButton />;
};
compiled:
import React from 'react';
import styled from 'styled-components';
export const ConditionalExpression = function({ fontSize }) {
const StyledButton = styled.button`
font-size: ${typeof fontSize === 'number' ? px2rem_1(fontSize) : props => px2rem_1(props?.theme.fontSize)};
`;
return React.createElement(StyledButton, null);
};
export const ConditionalExpressionWhenTrue = function({ fontSize }) {
const StyledButton = styled.button`
font-size: ${typeof fontSize !== 'number' ? props => px2rem_1(props?.theme.fontSize) : px2rem_1(fontSize)};
`;
return React.createElement(StyledButton, null);
};
function px2rem_1(input, ...args) {
if (typeof input === 'function') return px2rem_1(input(...args), ...args);
var value = parseFloat(input);
var pixels = Number.isNaN(value) ? 0 : value;
if (Math.abs(pixels) < 0) return `${pixels}px`;
var multiplier = Math.pow(10, 5 + 1);
var wholeNumber = Math.floor(((pixels * 1) / 100) * multiplier);
return `${(Math.round(wholeNumber / 10) * 10) / multiplier}rem`;
}
Other Expressions
Identifier, CallExpression, BinaryExpression, ...
source code:
import styled, { css, createGlobalStyle } from 'styled-components';
const fontSize = 18;
export const GlobalStyle = createGlobalStyle`
html body {
font-size: ${fontSize}px;
}
`;
function getHeight() {
const height = 100;
return height / 2;
}
const mixins = css`
padding: 0 16px;
`;
export const MixinsButton = styled.button`
${mixins};
height: ${getHeight()}px;
`;
const condition = false;
function calc() {
return 20;
}
export const BinaryExpression = styled.button`
${condition ||
`
width: 200px;
`};
height: ${condition || 100}px;
padding: ${40 + 50}px 8px ${4}px 16px;
line-height: ${calc() - 2}px;
`;
compiled:
import styled, { css, createGlobalStyle } from 'styled-components';
const fontSize = 18;
export const GlobalStyle = createGlobalStyle`
html body {
font-size: ${px2rem_1(fontSize)};
}
`;
function getHeight() {
const height = 100;
return height / 2;
}
const mixins = css`
padding: 0 0.16rem;
`;
export const MixinsButton = styled.button`
${mixins};
height: ${px2rem_1(getHeight())};
`;
const condition = false;
function calc() {
return 20;
}
export const BinaryExpression = styled.button`
${condition ||
`
width: 2rem;
`};
height: ${px2rem_1(condition || 100)};
padding: ${px2rem_1(40 + 50)} 0.08rem ${px2rem_1(4)} 0.16rem;
line-height: ${px2rem_1(calc() - 2)};
`;
function px2rem_1(input, ...args) {
if (typeof input === 'function') return px2rem_1(input(...args), ...args);
var value = parseFloat(input);
var pixels = Number.isNaN(value) ? 0 : value;
if (Math.abs(pixels) < 0) return `${pixels}px`;
var multiplier = Math.pow(10, 5 + 1);
var wholeNumber = Math.floor(((pixels * 1) / 100) * multiplier);
return `${(Math.round(wholeNumber / 10) * 10) / multiplier}rem`;
}