# html-version
parse and modify html file versions according to the
[html version spec](https://github.com/substack/html-version-spec)
# example
## parse
``` js
var fs = require('fs')
var versions = require('html-version')
fs.readFile(__dirname + '/page.html', function (err, src) {
console.log(versions.parse(src))
})
```
output:
```
{ integrity:
{ 'https://example.com/versions/1.0.0.html': [ 'sha256-mPjSxFzbBSy+LyCVyylIf5E/7zswbvsL4D/qxCAqrjY' ],
'https://example.com/versions/1.0.1.html': [ 'sha256-Qra3bKdpoprvRqkTF96gWOa0dPkA8MHYxOJqVsvkzIY=' ],
'https://example.com/versions/1.1.0.html': [ 'sha256-9VGwnCJuLbwo/N+TL1Ia9whqP8kVwEO8K0IFTUQk19o=' ] },
version: '1.2.0',
versions:
{ '1.0.0':
[ 'https://example.com/versions/1.0.0.html',
'magnet:?xt=urn:btih:4822271aa656ba6913a14edb117d3c4dc50f1209' ],
'1.0.1':
[ 'https://example.com/versions/1.0.1.html',
'ipfs:QmNcojAWDNwf1RZsPsG2ABvK4FVs7yq4iwSrKaMdPwV3Sh',
'magnet:?xt=urn:btih:d0320ebba035cc86526baae771da14912895e113' ],
'1.1.0':
[ 'https://example.com/versions/1.1.0.html',
'ipfs:QmWMey8Dd1ZH9XWRP3d7N1oSoL35uou1GSMpBwt4UahFSD' ] },
signature: [ 'https://example.com/versions/1.2.0.html.sig' ],
latest:
[ 'https://example.com/versions/latest.html',
'ipns:QmWJ9zRgvEvdzBPm1pshDqqFKqMXRJoHDQ4nuocHYS2REk',
'magnet:?xt=urn:btih:4a533d47ec9c7d95b1ad75f576cffc641853b750' ],
predecessor:
[ 'https://example.com/versions/1.1.0.html',
'ipfs:QmWMey8Dd1ZH9XWRP3d7N1oSoL35uou1GSMpBwt4UahFSD' ] }
```
## upgrade
``` js
var fs = require('fs')
var versions = require('html-version')
var prev = fs.readFileSync(__dirname + '/page.html')
var src = fs.readFileSync(__dirname + '/src.html')
var loc = [
'https://example.com/versions/1.2.0.html',
'ipfs:QmSguVEXZRRtDCRm3XGjvTQNnLHWkgowoFJ9jpCp5kEMEB'
]
console.log(versions.update(src, loc, versions.parse(prev)))
```
output:
```
whatever
```
# api
``` js
var versions = require('html-version')
```
## var info = versions.parse(html)
Parse a string of `html` into an object `info`:
* `info.version` - the `` contents
* `info.versions` - an object mapping semver version strings to arrays of URLs
* `info.integrity` - an object mapping URLs to arrays of integrity strings
* `info.signature` - an array of signature URLs
* `info.latest` - an array of latest version URLs
* `info.predecessor` - an array of predecessor version URLs
## var html = versions.meta(info)
Return meta and link tags in an `html` string for `info`, a parsed version
object.
## var html = versions.update(src, loc, prevInfo)
Update `src` with new meta and link tags that add to the previous version
metadata.
Return a string of `html` for a current html string `src`, the location of the
previous document as an array of URLs `loc`, and `prevInfo`, the parsed version
info for the previous html.
# thanks
Thanks to [blockai](https://blockai.com) for sponsoring this project.
# license
MIT