JarCastingHTTP Link Header
Parse & format HTTP link headers according to RFC 8288
Install via npm
$ npm install --save http-link-header
Deviations from the RFC
Link Target
While RFC 8288, Section 3.1 states that relative URI-References MUST be resolved by the parsers – this library DOES NOT. This is due to the parser not having an input for the absolute or canonical URI of the related document. Currently there are no plans to add this, and it is left to the user whether or not to resolve relative URIs.
Usage
var LinkHeader = require( 'http-link-header' )
Parsing a HTTP link header
var link = LinkHeader.parse(
'<example.com>; rel="example"; title="Example Website", ' +
'<example-01.com>; rel="alternate"; title="Alternate Example Domain"'
)
> Link {
refs: [
{ uri: 'example.com', rel: 'example', title: 'Example Website' },
{ uri: 'example-01.com', rel: 'alternate', title: 'Alternate Example Domain' },
]
}
Checking whether it has a reference with a given attribute & value
link.has( 'rel', 'alternate' )
> true
Retrieving a reference with a given attribute & value
link.get( 'rel', 'alternate' )
> [
{ uri: 'example-01.com', rel: 'alternate', title: 'Alternate Example Domain' }
]
// Shorthand for `rel` attributes
link.rel( 'alternate' )
> [
{ uri: 'example-01.com', rel: 'alternate', title: 'Alternate Example Domain' }
]
Setting references
link.set({ rel: 'next', uri: 'http://example.com/next' })
> Link {
refs: [
{ uri: 'example.com', rel: 'example', title: 'Example Website' },
{ uri: 'example-01.com', rel: 'alternate', title: 'Alternate Example Domain' },
{ rel: 'next', uri: 'http://example.com/next' }
]
}
Parsing multiple headers
var link = new LinkHeader()
link.parse( '<example.com>; rel="example"; title="Example Website"' )
> Link {
refs: [
{ uri: 'example.com', rel: 'example', title: 'Example Website' },
]
}
link.parse( '<example-01.com>; rel="alternate"; title="Alternate Example Domain"' )
> Link {
refs: [
{ uri: 'example.com', rel: 'example', title: 'Example Website' },
{ uri: 'example-01.com', rel: 'alternate', title: 'Alternate Example Domain' },
]
}
link.parse( '<example-02.com>; rel="alternate"; title="Second Alternate Example Domain"' )
> Link {
refs: [
{ uri: 'example.com', rel: 'example', title: 'Example Website' },
{ uri: 'example-01.com', rel: 'alternate', title: 'Alternate Example Domain' },
{ uri: 'example-02.com', rel: 'alternate', title: 'Second Alternate Example Domain' },
]
}
Handling extended attributes
link.parse( '</extended-attr-example>; rel=start; title*=UTF-8\'en\'%E2%91%A0%E2%93%AB%E2%85%93%E3%8F%A8%E2%99%B3%F0%9D%84%9E%CE%BB' )
> Link {
refs: [
{ uri: '/extended-attr-example', rel: 'start', 'title*': { language: 'en', encoding: null, value: '①⓫⅓㏨♳𝄞λ' } }
]
}
Stringifying to HTTP header format
link.toString()
> '<example.com>; rel=example; title="Example Website", <example-01.com>; rel=alternate; title="Alternate Example Domain"'
Speed
$ npm run benchmark
# http-link-header .parse() ⨉ 1000000
ok ~1.29 s (1 s + 289696759 ns)
# http-link-header #toString() ⨉ 1000000
ok ~554 ms (0 s + 553782657 ns)