https://github.com/deiu/linkheader

Link Header parser using Golang
https://github.com/deiu/linkheader

go golang header link

Last synced: about 1 year ago
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Link Header parser using Golang

• Host: GitHub
• URL: https://github.com/deiu/linkheader
• Owner: deiu
• License: mit
• Created: 2017-06-06T01:02:40.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2017-06-08T19:30:58.000Z (about 9 years ago)
• Last Synced: 2025-04-11T05:58:29.754Z (about 1 year ago)
• Topics: go, golang, header, link
• Language: Go
• Size: 18.6 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# linkheader

Golang tool to parse and set Link headers

[![Build Status](https://api.travis-ci.org/deiu/linkparser.svg?branch=master)](https://travis-ci.org/deiu/linkparser)

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[![GoReport](https://goreportcard.com/badge/github.com/deiu/linkheader)](https://goreportcard.com/report/github.com/deiu/linkheader)

[![GoDoc](https://godoc.org/github.com/deiu/linkheader?status.svg)](https://godoc.org/github.com/deiu/linkheader)

## Install

`go get -u github.com/deiu/linkparser`

## Usage

### Getting values from a Link header

The `ParseHeader()` function returns a map where link values are keyed based on `rel` values.

```golang

// the header value usually comes from an http.Request object, using

// req.Header.Get("Link")

header := `; rel="foo" title="hi", ; rel="bar"`

links = ParseHeader(header)

println(links["foo"]["href"]) // -> http://example.org

println(links["foo"]["title"]) // -> hi

println(links["bar"]["href"]) // -> http://test.com

```

### Setting values to a Link header

Golang's normal behavior when setting Link headers is a bit weird. For instance, doing something like `request.Header.Add("Link", headerValue)` several times with different values seems to append those values to the `Link` header slice. However, when reading back from that header with `request.Header.Get("Link")`, it only returns the first element of the slice. This behavior forced me to write my own function `AddLink()` to set multiple values to a Link header.

```golang

// the header value usually comes from an http.Request object, using

// req.Header.Get("Link")

oldHeader := req.Header.Get("Link")

println(oldHeader) // -> ""

// we need to build our list of parameters as per https://tools.ietf.org/html/rfc2068#section-19.6.2.4

params := map[string]string{"rel": "foo", "title": "bar"}

newHeader := AddLink(oldHeader, "http://example.org", params)

req.Header.Set("Link", newHeader)

oldHeader = req.Header.Get("Link")

println(oldHeader) // -> ; rel="foo"; title="bar"

params = map[string]string{"rel": "baz"}

newHeader = AddLink(oldHeader, "http://test.com", params)

req.Header.Set("Link", newHeader)

println(req.Header.Get("Link"))

// -> ; rel="foo"; title="bar", ; rel="baz"

```