Maintainer | Nickolay Kudasov <nickolay@getshoptv.com> |
---|---|
Stability | experimental |
Safe Haskell | None |
Language | Haskell2010 |
Swagger™ is a project used to describe and document RESTful APIs.
The Swagger specification defines a set of files required to describe such an API. These files can then be used by the Swagger-UI project to display the API and Swagger-Codegen to generate clients in various languages. Additional utilities can also take advantage of the resulting files, such as testing tools.
- module Data.Swagger.Lens
- module Data.Swagger.Operation
- module Data.Swagger.ParamSchema
- module Data.Swagger.Schema
- module Data.Swagger.Schema.Validation
- data Swagger = Swagger {
- _swaggerInfo :: Info
- _swaggerHost :: Maybe Host
- _swaggerBasePath :: Maybe FilePath
- _swaggerSchemes :: Maybe [Scheme]
- _swaggerConsumes :: MimeList
- _swaggerProduces :: MimeList
- _swaggerPaths :: InsOrdHashMap FilePath PathItem
- _swaggerDefinitions :: Definitions Schema
- _swaggerParameters :: Definitions Param
- _swaggerResponses :: Definitions Response
- _swaggerSecurityDefinitions :: Definitions SecurityScheme
- _swaggerSecurity :: [SecurityRequirement]
- _swaggerTags :: Set Tag
- _swaggerExternalDocs :: Maybe ExternalDocs
- data Host = Host {}
- data Scheme
- data Info = Info {}
- data Contact = Contact {}
- data License = License {
- _licenseName :: Text
- _licenseUrl :: Maybe URL
- data PathItem = PathItem {}
- data Operation = Operation {
- _operationTags :: Set TagName
- _operationSummary :: Maybe Text
- _operationDescription :: Maybe Text
- _operationExternalDocs :: Maybe ExternalDocs
- _operationOperationId :: Maybe Text
- _operationConsumes :: Maybe MimeList
- _operationProduces :: Maybe MimeList
- _operationParameters :: [Referenced Param]
- _operationResponses :: Responses
- _operationSchemes :: Maybe [Scheme]
- _operationDeprecated :: Maybe Bool
- _operationSecurity :: [SecurityRequirement]
- data Tag = Tag {}
- type TagName = Text
- data SwaggerType t where
- type Format = Text
- type Definitions = InsOrdHashMap Text
- data CollectionFormat t where
- data Param = Param {}
- data ParamAnySchema
- data ParamOtherSchema = ParamOtherSchema {}
- data ParamLocation
- type ParamName = Text
- data Header = Header {}
- type HeaderName = Text
- data Example = Example {}
- data ParamSchema t = ParamSchema {
- _paramSchemaDefault :: Maybe Value
- _paramSchemaType :: SwaggerType t
- _paramSchemaFormat :: Maybe Format
- _paramSchemaItems :: Maybe (SwaggerItems t)
- _paramSchemaMaximum :: Maybe Scientific
- _paramSchemaExclusiveMaximum :: Maybe Bool
- _paramSchemaMinimum :: Maybe Scientific
- _paramSchemaExclusiveMinimum :: Maybe Bool
- _paramSchemaMaxLength :: Maybe Integer
- _paramSchemaMinLength :: Maybe Integer
- _paramSchemaPattern :: Maybe Pattern
- _paramSchemaMaxItems :: Maybe Integer
- _paramSchemaMinItems :: Maybe Integer
- _paramSchemaUniqueItems :: Maybe Bool
- _paramSchemaEnum :: Maybe [Value]
- _paramSchemaMultipleOf :: Maybe Scientific
- data Schema = Schema {
- _schemaTitle :: Maybe Text
- _schemaDescription :: Maybe Text
- _schemaRequired :: [ParamName]
- _schemaAllOf :: Maybe [Schema]
- _schemaProperties :: InsOrdHashMap Text (Referenced Schema)
- _schemaAdditionalProperties :: Maybe (Referenced Schema)
- _schemaDiscriminator :: Maybe Text
- _schemaReadOnly :: Maybe Bool
- _schemaXml :: Maybe Xml
- _schemaExternalDocs :: Maybe ExternalDocs
- _schemaExample :: Maybe Value
- _schemaMaxProperties :: Maybe Integer
- _schemaMinProperties :: Maybe Integer
- _schemaParamSchema :: ParamSchema SwaggerKindSchema
- data NamedSchema = NamedSchema {}
- data SwaggerItems t where
- data Xml = Xml {
- _xmlName :: Maybe Text
- _xmlNamespace :: Maybe Text
- _xmlPrefix :: Maybe Text
- _xmlAttribute :: Maybe Bool
- _xmlWrapped :: Maybe Bool
- type Pattern = Text
- data Responses = Responses {}
- data Response = Response {}
- type HttpStatusCode = Int
- data SecurityScheme = SecurityScheme {}
- data SecuritySchemeType
- newtype SecurityRequirement = SecurityRequirement {}
- data ApiKeyParams = ApiKeyParams {}
- data ApiKeyLocation
- data OAuth2Params = OAuth2Params {}
- data OAuth2Flow
- type AuthorizationURL = Text
- type TokenURL = Text
- data ExternalDocs = ExternalDocs {}
- newtype Reference = Reference {
- getReference :: Text
- data Referenced a
- newtype MimeList = MimeList {
- getMimeList :: [MediaType]
- newtype URL = URL {}
How to use this library
This section explains how to use this library to work with Swagger specification.
Monoid
instances
Monoid
Virtually all types representing Swagger specification have
instances.
The Monoid
type class provides two methods — Monoid
and mempty
.mappend
In this library you can use
for a default/empty value. For instance:mempty
>>>
encode (mempty :: Swagger)
"{\"swagger\":\"2.0\",\"info\":{\"version\":\"\",\"title\":\"\"}}"
As you can see some spec properties (e.g. "version"
) are there even when the spec is empty.
That is because these properties are actually required ones.
You should always override the default (empty) value for these properties, although it is not strictly necessary:
>>>
encode mempty { _infoTitle = "Todo API", _infoVersion = "1.0" }
"{\"version\":\"1.0\",\"title\":\"Todo API\"}"
You can merge two values using
or its infix version mappend
(
:<>
)
>>>
encode $ mempty { _infoTitle = "Todo API" } <> mempty { _infoVersion = "1.0" }
"{\"version\":\"1.0\",\"title\":\"Todo API\"}"
This can be useful for combining specifications of endpoints into a whole API specification:
-- /account subAPI specification accountAPI :: Swagger -- /task subAPI specification taskAPI :: Swagger -- while API specification is just a combination -- of subAPIs' specifications api :: Swagger api = accountAPI <> taskAPI
Lenses and prisms
Since
has a fairly complex structure, lenses and prisms are used
to work comfortably with it. In combination with Swagger
instances, lenses
make it fairly simple to construct/modify any part of the specification:Monoid
>>>
:{
encode $ (mempty :: Swagger) & definitions .~ [ ("User", mempty & type_ .~ SwaggerString) ] & paths .~ [ ("/user", mempty & get ?~ (mempty & produces ?~ MimeList ["application/json"] & at 200 ?~ ("OK" & _Inline.schema ?~ Ref (Reference "User")) & at 404 ?~ "User info not found")) ] :} "{\"swagger\":\"2.0\",\"info\":{\"version\":\"\",\"title\":\"\"},\"paths\":{\"/user\":{\"get\":{\"produces\":[\"application/json\"],\"responses\":{\"404\":{\"description\":\"User info not found\"},\"200\":{\"schema\":{\"$ref\":\"#/definitions/User\"},\"description\":\"OK\"}}}}},\"definitions\":{\"User\":{\"type\":\"string\"}}}"
In the snippet above we declare an API with a single path /user
. This path provides method GET
which produces application/json
output. It should respond with code 200
and body specified
by schema User
which is defined in
property of swagger specification.
Alternatively it may respond with code definitions
404
meaning that user info is not found.
For convenience, swagger2
uses classy field lenses. It means that
field accessor names can be overloaded for different types. One such
common field is
. Many components of a Swagger specification
can have descriptions, and you can use the same name for them:description
>>>
encode $ (mempty :: Response) & description .~ "No content"
"{\"description\":\"No content\"}">>>
:{
encode $ (mempty :: Schema) & type_ .~ SwaggerBoolean & description ?~ "To be or not to be" :} "{\"description\":\"To be or not to be\",\"type\":\"boolean\"}"
is basically the base schema specification and many types contain it (see ParamSchema
).
So for convenience, all HasParamSchema
fields are transitively made fields of the type that has it.
For example, you can use ParamSchema
to access type_
of SwaggerType
schema without having to use Header
:paramSchema
>>>
encode $ (mempty :: Header) & type_ .~ SwaggerNumber
"{\"type\":\"number\"}"
Additionally, to simplify working with
, both Response
and Operation
have direct access to it via Responses
. Example:at
code
>>>
:{
encode $ (mempty :: Operation) & at 404 ?~ "Not found" :} "{\"responses\":{\"404\":{\"description\":\"Not found\"}}}"
You might've noticed that
has an extra underscore in its name
compared to, say, type_
field accessor.
This is because description
type
is a keyword in Haskell.
A few other field accessors are modified in this way:
Schema specification
and ParamSchema
are the two core types for data model specification.Schema
specifies all the common properties, available for every data schema.
The ParamSchema
tt
parameter imposes some restrictions on type
and items
properties (see
and SwaggerType
).SwaggerItems
is used for request and response bodies and allows specifying objects
with properties in addition to what Schema
provides.ParamSchema
In most cases you will have a Haskell data type for which you would like to
define a corresponding schema. To facilitate this use case
swagger2
provides two classes for schema encoding.
Both these classes provide means to encode types as Swagger schemas.
is intended to be used for primitive API endpoint parameters,
such as query parameters, headers and URL path pieces.
Its corresponding value-encoding class is ToParamSchema
(from ToHttpApiData
http-api-data
package).
is used for request and response bodies and mostly differ from
primitive parameters by allowing objects/mappings in addition to primitive types and arrays.
Its corresponding value-encoding class is ToSchema
(from ToJSON
aeson
package).
While lenses and prisms make it easy to define schemas, it might be that you don't need to:
and ToSchema
classes both have default ToParamSchema
-based implementations!Generic
default implementation is also aligned with ToSchema
default implementation with
the only difference being for sum encoding. ToJSON
defaults sum encoding to ToJSON
,
while defaultTaggedObject
defaults to something which corresponds to ToSchema
. This is due to
ObjectWithSingleField
behavior being hard to specify in Swagger.defaultTaggedObject
Here's an example showing
–ToJSON
correspondance:ToSchema
>>>
data Person = Person { name :: String, age :: Integer } deriving Generic
>>>
instance ToJSON Person
>>>
instance ToSchema Person
>>>
encode (Person "David" 28)
"{\"age\":28,\"name\":\"David\"}">>>
encode $ toSchema (Proxy :: Proxy Person)
"{\"required\":[\"name\",\"age\"],\"properties\":{\"name\":{\"type\":\"string\"},\"age\":{\"type\":\"integer\"}},\"type\":\"object\"}"
Please note that not all valid Haskell data types will have a proper swagger schema. For example while we can derive a schema for basic enums like
>>>
data SampleEnum = ChoiceOne | ChoiceTwo deriving Generic
>>>
instance ToSchema SampleEnum
>>>
instance ToJSON SampleEnum
and for sum types that have constructors with values
>>>
data SampleSumType = ChoiceInt Int | ChoiceString String deriving Generic
>>>
instance ToSchema SampleSumType
>>>
instance ToJSON SampleSumType
we can not derive a valid schema for a mix of the above. The following will result in a bad schema
>>>
data BadMixedType = ChoiceBool Bool | JustTag deriving Generic
>>>
instance ToSchema BadMixedType
>>>
instance ToJSON BadMixedType
This is due to the fact that
encodes empty constructors with an empty list which can not be described in a swagger schema.ToJSON
Manipulation
Sometimes you have to work with an imported or generated
.
For instance, http://hackage.haskell.org/package/servant-swagger generates basic Swagger
for a type-level servant API.Swagger
Lenses and prisms can be used to manipulate such specification to add additional information, tags, extra responses, etc.
To facilitate common needs, Data.Swagger.Operation
module provides useful helpers.
Validation
While
and ToParamSchema
provide means to easily obtain schemas for Haskell types,
there is no static mechanism to ensure those instances correspond to the ToSchema
or ToHttpApiData
instances.ToJSON
Data.Swagger.Schema.Validation
addresses
/ToJSON
validation.ToSchema
Re-exports
module Data.Swagger.Lens
module Data.Swagger.Operation
module Data.Swagger.ParamSchema
module Data.Swagger.Schema
Swagger specification
This is the root document object for the API specification.
Swagger | |
|
The host (name or ip) serving the API. It MAY include a port.
The transfer protocol of the API.
Info types
The object provides metadata about the API. The metadata can be used by the clients if needed, and can be presented in the Swagger-UI for convenience.
Info | |
|
Contact information for the exposed API.
Contact | |
|
License information for the exposed API.
License | |
|
PathItem
Describes the operations available on a single path.
A
may be empty, due to ACL constraints.
The path itself is still exposed to the documentation viewer
but they will not know which operations and parameters are available.PathItem
PathItem | |
|
Operations
Describes a single API operation on a path.
Operation | |
|
Allows adding meta data to a single tag that is used by Operation
.
It is not mandatory to have a Tag
per tag used there.
Tag | |
|
Eq Tag Source # | |
Data Tag Source # | |
Ord Tag Source # | |
Show Tag Source # | |
IsString Tag Source # | |
Generic Tag Source # | |
ToJSON Tag Source # | |
FromJSON Tag Source # | |
HasName Tag TagName Source # | |
HasTags Swagger (Set Tag) Source # | |
HasExternalDocs Tag (Maybe ExternalDocs) Source # | |
HasDescription Tag (Maybe Text) Source # | |
type Rep Tag Source # | |
Types and formats
data SwaggerType t where Source #
HasType Header (SwaggerType (SwaggerKindNormal * Header)) Source # | |
HasType NamedSchema (SwaggerType (SwaggerKindSchema *)) Source # | |
HasType Schema (SwaggerType (SwaggerKindSchema *)) Source # | |
HasType ParamOtherSchema (SwaggerType (SwaggerKindParamOtherSchema *)) Source # | |
Eq (SwaggerType t) Source # | |
Typeable * t => Data (SwaggerType (SwaggerKindNormal * t)) Source # | |
Data (SwaggerType (SwaggerKindParamOtherSchema *)) Source # | |
Data (SwaggerType (SwaggerKindSchema *)) Source # | |
Show (SwaggerType t) Source # | |
ToJSON (SwaggerType t) Source # | |
FromJSON (SwaggerType (SwaggerKindNormal * t)) Source # | |
FromJSON (SwaggerType (SwaggerKindParamOtherSchema *)) Source # | |
FromJSON (SwaggerType (SwaggerKindSchema *)) Source # | |
SwaggerMonoid (SwaggerType t) Source # | |
AesonDefaultValue (SwaggerType a) Source # | |
HasType (ParamSchema t0) (SwaggerType t0) Source # | |
type Definitions = InsOrdHashMap Text Source #
A list of definitions that can be used in references.
data CollectionFormat t where Source #
Determines the format of the array.
Parameters
Describes a single operation parameter. A unique parameter is defined by a combination of a name and location.
Param | |
|
data ParamAnySchema Source #
data ParamOtherSchema Source #
ParamOtherSchema | |
|
data ParamLocation Source #
ParamQuery | Parameters that are appended to the URL.
For example, in |
ParamHeader | Custom headers that are expected as part of the request. |
ParamPath | Used together with Path Templating, where the parameter value is actually part of the operation's URL.
This does not include the host or base path of the API.
For example, in |
ParamFormData | Used to describe the payload of an HTTP request when either |
Header | |
|
type HeaderName = Text Source #
Schemas
data ParamSchema t Source #
ParamSchema | |
|
data NamedSchema Source #
A
with an optional name.
This name can be used in references.Schema
data SwaggerItems t where Source #
Items for
schemas.SwaggerArray
should be used only for query params, headers and path pieces.
The SwaggerItemsPrimitive
parameter specifies how elements of an array should be displayed.
Note that CollectionFormat
tfmt
in
specifies format for elements of type SwaggerItemsPrimitive
fmt schemaschema
.
This is different from the original Swagger's Items Object.
should be used to specify homogenous array SwaggerItemsObject
s.Schema
should be used to specify tuple SwaggerItemsArray
s.Schema
HasParamSchema s (ParamSchema t) => HasItems s (Maybe (SwaggerItems t)) Source # | |
Eq (SwaggerItems t) Source # | |
Data t => Data (SwaggerItems (SwaggerKindNormal * t)) Source # | |
Data (SwaggerItems (SwaggerKindParamOtherSchema *)) Source # | |
Data (SwaggerItems (SwaggerKindSchema *)) Source # | |
Show (SwaggerItems t) Source # | |
ToJSON (ParamSchema t) => ToJSON (SwaggerItems t) Source # | |
(FromJSON (CollectionFormat (SwaggerKindNormal * t)), FromJSON (ParamSchema (SwaggerKindNormal * t))) => FromJSON (SwaggerItems (SwaggerKindNormal * t)) Source # | |
FromJSON (SwaggerItems (SwaggerKindParamOtherSchema *)) Source # | |
FromJSON (SwaggerItems (SwaggerKindSchema *)) Source # | |
HasItems (ParamSchema t0) (Maybe (SwaggerItems t0)) Source # | |
Xml | |
|
Eq Xml Source # | |
Data Xml Source # | |
Show Xml Source # | |
Generic Xml Source # | |
ToJSON Xml Source # | |
FromJSON Xml Source # | |
HasName Xml (Maybe Text) Source # | |
HasXml Schema (Maybe Xml) Source # | |
HasWrapped Xml (Maybe Bool) Source # | |
HasPrefix Xml (Maybe Text) Source # | |
HasNamespace Xml (Maybe Text) Source # | |
HasAttribute Xml (Maybe Bool) Source # | |
type Rep Xml Source # | |
Responses
A container for the expected responses of an operation. The container maps a HTTP response code to the expected response. It is not expected from the documentation to necessarily cover all possible HTTP response codes, since they may not be known in advance. However, it is expected from the documentation to cover a successful operation response and any known errors.
Responses | |
|
Describes a single response from an API Operation.
Response | |
|
type HttpStatusCode = Int Source #
Security
data SecurityScheme Source #
SecurityScheme | |
|
data SecuritySchemeType Source #
newtype SecurityRequirement Source #
Lists the required security schemes to execute this operation. The object can have multiple security schemes declared in it which are all required (that is, there is a logical AND between the schemes).
API key
data ApiKeyParams Source #
ApiKeyParams | |
|
data ApiKeyLocation Source #
The location of the API key.
OAuth2
data OAuth2Params Source #
OAuth2Params | |
|
data OAuth2Flow Source #
type AuthorizationURL = Text Source #
The authorization URL to be used for OAuth2 flow. This SHOULD be in the form of a URL.
The token URL to be used for OAuth2 flow. This SHOULD be in the form of a URL.
External documentation
data ExternalDocs Source #
Allows referencing an external resource for extended documentation.
ExternalDocs | |
|
References
A simple object to allow referencing other definitions in the specification. It can be used to reference parameters and responses that are defined at the top level for reuse.
data Referenced a Source #
Functor Referenced Source # | |
HasParameters Operation [Referenced Param] Source # | |
HasParameters PathItem [Referenced Param] Source # | |
HasSchema Response (Maybe (Referenced Schema)) Source # | |
HasAdditionalProperties Schema (Maybe (Referenced Schema)) Source # | |
HasDefault Responses (Maybe (Referenced Response)) Source # | |
HasResponses Responses (InsOrdHashMap HttpStatusCode (Referenced Response)) Source # | |
HasProperties Schema (InsOrdHashMap Text (Referenced Schema)) Source # | |
Eq a => Eq (Referenced a) Source # | |
Data a => Data (Referenced a) Source # | |
Show a => Show (Referenced a) Source # | |
IsString a => IsString (Referenced a) Source # | |
ToJSON (Referenced Response) Source # | |
ToJSON (Referenced Schema) Source # | |
ToJSON (Referenced Param) Source # | |
FromJSON (Referenced Response) Source # | |
FromJSON (Referenced Schema) Source # | |
FromJSON (Referenced Param) Source # | |
Monoid a => SwaggerMonoid (Referenced a) Source # | |
Miscellaneous
MimeList | |
|