wai-3.2.1: Web Application Interface.

Safe HaskellNone



Internal constructors and helper functions. Note that no guarantees are given for stability of these interfaces.



data Request Source

Information on the request sent by the client. This abstracts away the details of the underlying implementation.




requestMethod :: Method

Request method such as GET.

httpVersion :: HttpVersion

HTTP version such as 1.1.

rawPathInfo :: ByteString

Extra path information sent by the client. The meaning varies slightly depending on backend; in a standalone server setting, this is most likely all information after the domain name. In a CGI application, this would be the information following the path to the CGI executable itself.

Middlewares and routing tools should not modify this raw value, as it may be used for such things as creating redirect destinations by applications. Instead, if you are writing a middleware or routing framework, modify the pathInfo instead. This is the approach taken by systems like Yesod subsites.

Note: At the time of writing this documentation, there is at least one system (Network.Wai.UrlMap from wai-extra) that does not follow the above recommendation. Therefore, it is recommended that you test the behavior of your application when using rawPathInfo and any form of library that might modify the Request.

rawQueryString :: ByteString

If no query string was specified, this should be empty. This value will include the leading question mark. Do not modify this raw value - modify queryString instead.

requestHeaders :: RequestHeaders

A list of headers (a pair of key and value) in an HTTP request.

isSecure :: Bool

Was this request made over an SSL connection?

Note that this value will not tell you if the client originally made this request over SSL, but rather whether the current connection is SSL. The distinction lies with reverse proxies. In many cases, the client will connect to a load balancer over SSL, but connect to the WAI handler without SSL. In such a case, isSecure will be False, but from a user perspective, there is a secure connection.

remoteHost :: SockAddr

The client's host information.

pathInfo :: [Text]

Path info in individual pieces - the URL without a hostname/port and without a query string, split on forward slashes.

queryString :: Query

Parsed query string information.

requestBody :: IO ByteString

Get the next chunk of the body. Returns empty when the body is fully consumed.

vault :: Vault

A location for arbitrary data to be shared by applications and middleware.

requestBodyLength :: RequestBodyLength

The size of the request body. In the case of a chunked request body, this may be unknown.

Since 1.4.0

requestHeaderHost :: Maybe ByteString

The value of the Host header in a HTTP request.

Since 2.0.0

requestHeaderRange :: Maybe ByteString

The value of the Range header in a HTTP request.

Since 2.0.0

requestHeaderReferer :: Maybe ByteString

The value of the Referer header in a HTTP request.

Since 3.2.0

requestHeaderUserAgent :: Maybe ByteString

The value of the User-Agent header in a HTTP request.

Since 3.2.0


type StreamingBody = (Builder -> IO ()) -> IO () -> IO () Source

Represents a streaming HTTP response body. It's a function of two parameters; the first parameter provides a means of sending another chunk of data, and the second parameter provides a means of flushing the data to the client.

Since 3.0.0

data RequestBodyLength Source

The size of the request body. In the case of chunked bodies, the size will not be known.

Since 1.4.0

data FilePart Source

Information on which part to be sent. Sophisticated application handles Range (and If-Range) then create FilePart.


data ResponseReceived Source

A special datatype to indicate that the WAI handler has received the response. This is to avoid the need for Rank2Types in the definition of Application.

It is highly advised that only WAI handlers import and use the data constructor for this data type.

Since 3.0.0