Overriding approot - yesodweb/yesod GitHub Wiki

This page demonstrates different ways you may wish to override the approot method.

Relative Approot

This will use no root at all. Keep in mind this will not work with emails and RSS feeds.

approot = ApprootRelative

Static Approot

Note absence of trailing slash

approot = ApprootStatic "http://localhost"

Approot from master settings

Get a static application root from runtime configuration stored in the foundation datatype:

approot = ApprootMaster $ appRoot . appSettings

Approot based on request

This will use the approot from appSettings but fall back to the http host header field

approot = ApprootRequest $ \app req ->
    case appRoot $ appSettings app of
        Nothing -> getApprootText guessApproot app req
        Just root -> root

app here is the master site and req is the request.

---

This will get the approot from the request header host field:

approot = guessApproot

---

Same as above but instead of guessing if links should be https(based on the X-Forwarded-Proto header for example) will only make links https:// if the connection is actually secure.

import Network.Wai (requestHeaderHost, isSecure)

approot = ApprootRequest $ \_ r -> maybe ""
    (mappend (if isSecure r then "https://" else "http://") . decodeUtf8)
    (requestHeaderHost r)