# HTTP Referrer

The Referrer-Policy HTTP header controls how much referrer information (sent via the Referer header) should be included with requests.

Read more at [developer.mozilla.org](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy)

Iris uses the [Shopify's goreferrer](https://github.com/Shopify/goreferrer/pull/27) package to expose the `Context.GetReferrer()` method.

The `GetReferrer` method extracts and returns the information from the `"Referer"` (or `"Referrer"`) header and url query parameter as specified in <https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy>.

```go
GetReferrer() Referrer
```

Which `Referrer` looks like that:

```go
type Referrer struct {
        Type       ReferrerType
        Label      string
        URL        string
        Subdomain  string
        Domain     string
        Tld        string         
        Path       string              
        Query      string                 
        GoogleType ReferrerGoogleSearchType
}
```

The `ReferrerType` is the enum for a Referrer.Type value (indirect, direct, email, search, social). The available types are:

```go
ReferrerInvalid
ReferrerIndirect
ReferrerDirect
ReferrerEmail
ReferrerSearch
ReferrerSocial
```

The `GoogleType` can be one of those:

```go
ReferrerNotGoogleSearch
ReferrerGoogleOrganicSearch
ReferrerGoogleAdwords
```

## Example

```go
package main

import "github.com/kataras/iris/v12"

func main() {
    app := iris.New()

    app.Get("/", func(ctx iris.Context) {
        r := ctx.GetReferrer()
        switch r.Type {
        case iris.ReferrerSearch:
            ctx.Writef("Search %s: %s\n", r.Label, r.Query)
            ctx.Writef("Google: %s\n", r.GoogleType)
        case iris.ReferrerSocial:
            ctx.Writef("Social %s\n", r.Label)
        case iris.ReferrerIndirect:
            ctx.Writef("Indirect: %s\n", r.URL)
        }
    })

    app.Listen(":8080")
}
```

How to `curl`:

```bash
curl http://localhost:8080?\
referrer=https://twitter.com/Xinterio/status/1023566830974251008

curl http://localhost:8080?\
referrer=https://www.google.com/search?q=Top+6+golang+web+frameworks\
&oq=Top+6+golang+web+frameworks
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://iris-go.gitbook.io/iris/contents/http-referrer.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.