| Safe Haskell | Safe |
|---|---|
| Language | Haskell2010 |
Network.HTTP.Media
Description
A framework for parsing HTTP media type headers.
- data MediaType
- (//) :: ByteString -> ByteString -> MediaType
- (/:) :: MediaType -> (ByteString, ByteString) -> MediaType
- mainType :: MediaType -> CI ByteString
- subType :: MediaType -> CI ByteString
- parameters :: MediaType -> Parameters
- (/?) :: MediaType -> ByteString -> Bool
- (/.) :: MediaType -> ByteString -> Maybe (CI ByteString)
- data Language
- toParts :: Language -> [CI ByteString]
- matchAccept :: Accept a => [a] -> ByteString -> Maybe a
- mapAccept :: Accept a => [(a, b)] -> ByteString -> Maybe b
- mapAcceptMedia :: [(MediaType, b)] -> ByteString -> Maybe b
- mapAcceptLanguage :: [(Language, b)] -> ByteString -> Maybe b
- mapAcceptBytes :: [(ByteString, b)] -> ByteString -> Maybe b
- matchContent :: Accept a => [a] -> ByteString -> Maybe a
- mapContent :: Accept a => [(a, b)] -> ByteString -> Maybe b
- mapContentMedia :: [(MediaType, b)] -> ByteString -> Maybe b
- mapContentLanguage :: [(Language, b)] -> ByteString -> Maybe b
- data Quality a
- parseQuality :: Accept a => ByteString -> Maybe [Quality a]
- matchQuality :: Accept a => [a] -> [Quality a] -> Maybe a
- mapQuality :: Accept a => [(a, b)] -> [Quality a] -> Maybe b
- class Show a => Accept a where
- class RenderHeader h where
Media types
An HTTP media type, consisting of the type, subtype, and parameters.
(//) :: ByteString -> ByteString -> MediaType Source #
Builds a MediaType without parameters. Can produce an error if
either type is invalid.
(/:) :: MediaType -> (ByteString, ByteString) -> MediaType Source #
Adds a parameter to a MediaType. Can produce an error if either
string is invalid.
parameters :: MediaType -> Parameters Source #
Retrieves the parameters of a MediaType.
(/?) :: MediaType -> ByteString -> Bool Source #
Evaluates if a MediaType has a parameter of the given name.
(/.) :: MediaType -> ByteString -> Maybe (CI ByteString) Source #
Retrieves a parameter from a MediaType.
Languages
Suitable for HTTP language-ranges as defined in RFC2616.
Specifically:
language-range = ( ( 1*8ALPHA *( "-" 1*8ALPHA ) ) | "*" )
toParts :: Language -> [CI ByteString] Source #
Converts Language to a list of its language parts. The wildcard
produces an empty list.
Accept matching
Arguments
| :: Accept a | |
| => [a] | The server-side options |
| -> ByteString | The client-side header value |
| -> Maybe a |
Matches a list of server-side resource options against a quality-marked
list of client-side preferences. A result of Nothing means that nothing
matched (which should indicate a 406 error). If two or more results arise
with the same quality level and specificity, then the first one in the
server list is chosen.
The use of the Accept type class allows the application of either
MediaType for the standard Accept header or ByteString for any other
Accept header which can be marked with a quality value.
matchAccept ["text/html", "application/json"] <$> getHeader
For more information on the matching process see RFC 2616, section 14.1-4.
Arguments
| :: Accept a | |
| => [(a, b)] | The map of server-side preferences to values |
| -> ByteString | The client-side header value |
| -> Maybe b |
The equivalent of matchAccept above, except the resulting choice is
mapped to another value. Convenient for specifying how to translate the
resource into each of its available formats.
getHeader >>= maybe render406Error renderResource . mapAccept
[ ("text" // "html", asHtml)
, ("application" // "json", asJson)
]Arguments
| :: [(MediaType, b)] | The map of server-side preferences to values |
| -> ByteString | The client-side header value |
| -> Maybe b |
Arguments
| :: [(Language, b)] | The map of server-side preferences to values |
| -> ByteString | The client-side header value |
| -> Maybe b |
Arguments
| :: [(ByteString, b)] | The map of server-side preferences to values |
| -> ByteString | The client-side header value |
| -> Maybe b |
A specialisation of mapAccept that only takes ByteString as its
input, to avoid ambiguous-type errors when using string literal
overloading.
getHeader >>= maybe render406Error encodeResourceWith . mapAcceptBytes
[ ("compress", compress)
, ("gzip", gzip)
]Content matching
Arguments
| :: Accept a | |
| => [a] | The server-side response options |
| -> ByteString | The client's request value |
| -> Maybe a |
Matches a list of server-side parsing options against a the client-side
content value. A result of Nothing means that nothing matched (which
should indicate a 415 error).
matchContent ["application/json", "text/plain"] <$> getContentType
For more information on the matching process see RFC 2616, section 14.17.
Arguments
| :: Accept a | |
| => [(a, b)] | The map of server-side responses |
| -> ByteString | The client request's header value |
| -> Maybe b |
The equivalent of matchContent above, except the resulting choice is
mapped to another value.
getContentType >>= maybe send415Error readRequestBodyWith . mapContent
[ ("application" // "json", parseJson)
, ("text" // "plain", parseText)
]Arguments
| :: [(MediaType, b)] | The map of server-side responses |
| -> ByteString | The client request's header value |
| -> Maybe b |
A specialisation of mapContent that only takes MediaType as its
input, to avoid ambiguous-type errors when using string literal
overloading.
getContentType >>=
maybe send415Error readRequestBodyWith . mapContentMedia
[ ("application/json", parseJson)
, ("text/plain", parseText)
]Arguments
| :: [(Language, b)] | The map of server-side responses |
| -> ByteString | The client request's header value |
| -> Maybe b |
A specialisation of mapContent that only takes Language as its input,
to avoid ambiguous-type errors when using string literal overloading.
getContentType >>=
maybe send415Error readRequestBodyWith . mapContentLanguage
[ ("application/json", parseJson)
, ("text/plain", parseText)
]Quality values
Attaches a quality value to data.
parseQuality :: Accept a => ByteString -> Maybe [Quality a] Source #
Parses a full Accept header into a list of quality-valued media types.
Arguments
| :: Accept a | |
| => [a] | The server-side options |
| -> [Quality a] | The pre-parsed client-side header value |
| -> Maybe a |
Matches a list of server-side resource options against a pre-parsed
quality-marked list of client-side preferences. A result of Nothing means
that nothing matched (which should indicate a 406 error). If two or more
results arise with the same quality level and specificity, then the first
one in the server list is chosen.
The use of the Accept type class allows the application of either
MediaType for the standard Accept header or ByteString for any other
Accept header which can be marked with a quality value.
matchQuality ["text/html", "application/json"] <$> parseQuality header
For more information on the matching process see RFC 2616, section 14.1-4.
Arguments
| :: Accept a | |
| => [(a, b)] | The map of server-side preferences to values |
| -> [Quality a] | The client-side header value |
| -> Maybe b |
The equivalent of matchQuality above, except the resulting choice is
mapped to another value. Convenient for specifying how to translate the
resource into each of its available formats.
parseQuality header >>= maybe render406Error renderResource . mapQuality
[ ("text" // "html", asHtml)
, ("application" // "json", asJson)
]Accept
class Show a => Accept a where Source #
Defines methods for a type whose values can be matched against each other in terms of an HTTP Accept-* header.
This allows functions to work on both the standard Accept header and others such as Accept-Language that still may use quality values.
Minimal complete definition
Methods
parseAccept :: ByteString -> Maybe a Source #
Specifies how to parse an Accept-* header after quality has been handled.
matches :: a -> a -> Bool Source #
Evaluates whether either the left argument matches the right one.
This relation must be a total order, where more specific terms on the left can produce a match, but a less specific term on the left can never produce a match. For instance, when matching against media types it is important that if the client asks for a general type then we can choose a more specific offering from the server, but if a client asks for a specific type and the server only offers a more general form, then we cannot generalise. In this case, the server types will be the left argument, and the client types the right.
For types with no concept of specificity, this operation is just equality.
moreSpecificThan :: a -> a -> Bool Source #
Evaluates whether the left argument is more specific than the right.
This relation must be irreflexive and transitive. For types with no concept of specificity, this is the empty relation (always false).
hasExtensionParameters :: Proxy a -> Bool Source #
Indicates whether extension parameters are permitted after the weight parameter when this type appears in an Accept header. Defaults to false.
Rendering
class RenderHeader h where Source #
A class for header values, so they may be rendered to their ByteString
representation. Lists of header values and quality-marked header values
will render appropriately.
Minimal complete definition
Instances