svg-pathdata
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Manipulate SVG path data (path[d] attribute content) simply and efficiently.
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# svg-pathdata
> Manipulate SVG path data (path[d] attribute content) simply and efficiently.
[](https://github.com/nfroidure/svg-pathdata/blob/main/LICENSE)
[](https://npmjs.com/package/svg-pathdata)
[](https://nodejs.org)
[](https://github.com/nfroidure/svg-pathdata/actions)
## Usage
Install the module:
```sh
npm install --save svg-pathdata
```
Then in your JavaScript files:
```js
import {
SVGPathData,
SVGPathDataTransformer,
SVGPathDataEncoder,
SVGPathDataParser,
} from 'svg-pathdata';
```
## Reading PathData
```js
const pathData = new SVGPathData(`
M 10 10
H 60
V 60
L 10 60
Z`);
console.log(pathData.commands);
// [ {type: SVGPathData.MOVE_TO, relative: false, x: 10, y: 10},
// {type: SVGPathData.HORIZ_LINE_TO, relative: false, x: 60},
// {type: SVGPathData.VERT_LINE_TO, relative: false, y: 60},
// {type: SVGPathData.LINE_TO, relative: false, x: 10, y: 60},
// {type: SVGPathData.CLOSE_PATH}]
```
## Reading PathData in chunks
```js
const parser = new SVGPathDataParser();
parser.parse(' '); // returns []
parser.parse('M 10'); // returns []
parser.parse(' 10'); // returns [{type: SVGPathData.MOVE_TO, relative: false, x: 10, y: 10 }]
parser.write('H 60'); // returns [{type: SVGPathData.HORIZ_LINE_TO, relative: false, x: 60 }]
parser.write('V'); // returns []
parser.write('60'); // returns [{type: SVGPathData.VERT_LINE_TO, relative: false, y: 60 }]
parser.write('L 10 60 \n Z');
// returns [
// {type: SVGPathData.LINE_TO, relative: false, x: 10, y: 60 },
// {type: SVGPathData.CLOSE_PATH }]
parser.finish(); // tell parser there is no more data: will throw if there are unfinished commands.
```
## Outputting PathData
```js
const pathData = new SVGPathData(`
M 10 10
H 60
V 60
L 10 60
Z`);
// returns "M10 10H60V60L10 60Z"
encodeSVGPath({ type: SVGPathData.MOVE_TO, relative: false, x: 10, y: 10 });
// returns "M10 10"
encodeSVGPath({ type: SVGPathData.HORIZ_LINE_TO, relative: false, x: 60 });
// returns "H60"
encodeSVGPath([
{ type: SVGPathData.VERT_LINE_TO, relative: false, y: 60 },
{ type: SVGPathData.LINE_TO, relative: false, x: 10, y: 60 },
{ type: SVGPathData.CLOSE_PATH },
]);
// returns "V60L10 60Z"
```
## Transforming PathData
This library can perform transformations on SVG paths. Here is
[an example of that kind of use](https://github.com/nfroidure/svgicons2svgfont/blob/aa6df0211419e9d61c417c63bcc353f0cb2ea0c8/src/index.js#L192).
### Transforming entire paths
```js
new SVGPathData(`
m 10,10
h 60
v 60
l 10,60
z`)
.toAbs()
.encode();
// return s"M10,10 H70 V70 L80,130 Z"
```
### Transforming partial data
Here, we take SVGPathData from stdin and output it transformed to stdout.
```js
const transformingParser = new SVGPathDataParser().toAbs().scale(2, 2);
transformingParser.parse('m 0 0'); // returns [{ type: SVGPathData.MOVE_TO, relative: false, x: 0, y: 0 }]
transformingParser.parse('l 2 3'); // returns [{ type: SVGPathData.LINE_TO, relative: false, x: 4, y: 6 }]
```
## Supported transformations
You can find all supported transformations in
[src/SVGPathDataTransformer.ts](https://github.com/nfroidure/SVGPathData/blob/master/src/SVGPathDataTransformer.ts#L47).
Additionally, you can create your own by writing a function with the following
signature:
```js
type TransformFunction = (command: SVGCommand) => SVGCommand | SVGCommand[];
function SET_X_TO(xValue = 10) {
return function(command) {
command.x = xValue; // transform command objects and return them
return command;
};
};
// Synchronous usage
new SVGPathData('...')
.transform(SET_X_TO(25))
.encode();
// Chunk usage
new SVGPathDataParser().transform(SET_X_TO(25));
```
## Contributing
Clone this project, run:
```sh
npm install; npm test
```
# Authors
- [Nicolas Froidure](https://insertafter.com/en/index.html)
- [Anders Kaseorg](mailto:andersk@mit.edu)
# License
[MIT](https://github.com/nfroidure/svg-pathdata/blob/main/LICENSE)