108 lines
2.3 KiB
Markdown
108 lines
2.3 KiB
Markdown
# CSS Tokenizer
|
|
|
|
[<img alt="npm version" src="https://img.shields.io/npm/v/@csstools/css-tokenizer.svg" height="20">][npm-url]
|
|
[<img alt="Build Status" src="https://github.com/csstools/postcss-plugins/workflows/test/badge.svg" height="20">][cli-url]
|
|
[<img alt="Discord" src="https://shields.io/badge/Discord-5865F2?logo=discord&logoColor=white">][discord]
|
|
|
|
Implemented from : https://www.w3.org/TR/2021/CRD-css-syntax-3-20211224/
|
|
|
|
## Usage
|
|
|
|
Add [CSS Tokenizer] to your project:
|
|
|
|
```bash
|
|
npm install @csstools/css-tokenizer --save-dev
|
|
```
|
|
|
|
```js
|
|
import { tokenizer, TokenType } from '@csstools/css-tokenizer';
|
|
|
|
const myCSS = `@media only screen and (min-width: 768rem) {
|
|
.foo {
|
|
content: 'Some content!' !important;
|
|
}
|
|
}
|
|
`;
|
|
|
|
const t = tokenizer({
|
|
css: myCSS,
|
|
});
|
|
|
|
while (true) {
|
|
const token = t.nextToken();
|
|
if (token[0] === TokenType.EOF) {
|
|
break;
|
|
}
|
|
|
|
console.log(token);
|
|
}
|
|
```
|
|
|
|
Or use the `tokenize` helper function:
|
|
|
|
```js
|
|
import { tokenize } from '@csstools/css-tokenizer';
|
|
|
|
const myCSS = `@media only screen and (min-width: 768rem) {
|
|
.foo {
|
|
content: 'Some content!' !important;
|
|
}
|
|
}
|
|
`;
|
|
|
|
const tokens = tokenize({
|
|
css: myCSS,
|
|
});
|
|
|
|
console.log(tokens);
|
|
```
|
|
|
|
### Options
|
|
|
|
```ts
|
|
{
|
|
onParseError?: (error: ParseError) => void
|
|
}
|
|
```
|
|
|
|
#### `onParseError`
|
|
|
|
The tokenizer is forgiving and won't stop when a parse error is encountered.
|
|
Parse errors also aren't tokens.
|
|
|
|
To receive parsing error information you can set a callback.
|
|
|
|
```js
|
|
import { tokenizer, TokenType } from '@csstools/css-tokenizer';
|
|
|
|
const t = tokenizer({
|
|
css: '\\',
|
|
}, { onParseError: (err) => console.warn(err) });
|
|
|
|
while (true) {
|
|
const token = t.nextToken();
|
|
if (token[0] === TokenType.EOF) {
|
|
break;
|
|
}
|
|
}
|
|
```
|
|
|
|
Parser errors will try to inform you about the point in the tokenizer logic the error happened.
|
|
This tells you the kind of error.
|
|
|
|
## Goals and non-goals
|
|
|
|
Things this package aims to be:
|
|
- specification compliant CSS tokenizer
|
|
- a reliable low level package to be used in CSS parsers
|
|
|
|
What it is not:
|
|
- opinionated
|
|
- fast
|
|
- small
|
|
|
|
[cli-url]: https://github.com/csstools/postcss-plugins/actions/workflows/test.yml?query=workflow/test
|
|
[discord]: https://discord.gg/bUadyRwkJS
|
|
[npm-url]: https://www.npmjs.com/package/@csstools/css-tokenizer
|
|
|
|
[CSS Tokenizer]: https://github.com/csstools/postcss-plugins/tree/main/packages/css-tokenizer
|