# gpx-parser-builder
A simple gpx parser and builder between GPX string and JavaScript object. It is dependent on [isomorphic-xml2js](https://github.com/RikkiGibson/isomorphic-xml2js).

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## Requirements

gpx-parser-builder is written with ECMAScript 6. You can leverage [Babel](https://babeljs.io/) and [Webpack](https://webpack.js.org/) to make all browsers available.

## Installation

```bash
npm install gpx-parser-builder --save
```

## Version

v1.0.0+ is a breaking change for v0.2.2-. v1.0.0+ fully supports gpx files including waypoints, routes, and tracks. Every gpx type is 1-1 corresponding to a JavaScript class.

## Usage

```javascript
import GPX from 'gpx-parser-builder';

// Parse gpx
const gpx = GPX.parse('GPX_STRING');

window.console.dir(gpx.metadata);
window.console.dir(gpx.wpt);
window.console.dir(gpx.trk);

// Build gpx
window.console.log(gpx.toString());
```

Get more details about usage with the unit tests.

### GPX

The GPX JavaScript object.

`constructor(object)` 

```javascript
const gpx = new Gpx({$:{...}, metadat: {...}, wpt:[{...},{...}]}, trk: {...}, rte: {...})
```

#### Member Variables

`$` the attributes for the gpx element. Default value:
```javascript
{
    'version': '1.1',
    'creator': 'gpx-parser-builder',
    'xmlns': 'http://www.topografix.com/GPX/1/1',
    'xmlns:xsi': 'http://www.w3.org/2001/XMLSchema-instance',
    'xsi:schemaLocation': 'http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd'
}
```

`metadata` the metadata for the gpx.

`wpt` array of waypoints. It is corresponded to `<wpt>`. The type of all elements in `wpt` is `Waypoint`;

`rte` array of routes. It is corresponded to `<rte>`. The type of all elements in `rte` is `Route`;

`trk` array of tracks. It is corresponded to `<trk>`. The type of all elements in `trk` is `Track`;

#### Static Methods

`parse(gpxString)` parse gpx string to Gpx object. return `null` if parsing failed.

#### Member Methods

`toString(options)` GPX object to gpx string. The options is for [isomorphic-xml2js](https://github.com/RikkiGibson/isomorphic-xml2js).

## Save as GPX file in the frontend

You can leverage [StreamSaver.js](https://github.com/jimmywarting/StreamSaver.js) or [FileSaver.js](https://github.com/eligrey/FileSaver.js) to save as GPX file. ⚠️Not all borwsers support the above file techniques. ⚠️️️

## Author

Zheng-Xiang Ke, kf99916@gmail.com

## License

gpx-parser-builder is available under the MIT license. See the LICENSE file for more info.