Documentation

Convert a type into Schema.

An example type and instance:

{-# LANGUAGE OverloadedStrings #-}   -- allows to write Text literals
{-# LANGUAGE OverloadedLists #-}     -- allows to write Map and HashMap as lists

import Control.Lens

data Coord = Coord { x :: Double, y :: Double }

instance ToSchema Coord where
  declareNamedSchema = pure (Just "Coord", schema)
   where
     schema = mempty
       & type_ .~ SwaggerObject
       & properties .~
           [ ("x", toSchemaRef (Proxy :: Proxy Double))
           , ("y", toSchemaRef (Proxy :: Proxy Double))
           ]
       & required .~ [ "x", "y" ]

Instead of manually writing your ToSchema instance you can use a default generic implementation of declareNamedSchema.

To do that, simply add deriving Generic clause to your datatype and declare a ToSchema instance for your datatype without giving definition for declareNamedSchema.

For instance, the previous example can be simplified into this:

{-# LANGUAGE DeriveGeneric #-}

import GHC.Generics (Generic)

data Coord = Coord { x :: Double, y :: Double } deriving Generic

instance ToSchema Coord

Convert a type into a schema and declare all used schema definitions.

Convert a type into an optionally named schema.

>>> toNamedSchema (Proxy :: Proxy String) ^. name
Nothing
>>> encode (toNamedSchema (Proxy :: Proxy String) ^. schema)
"{\"type\":\"string\"}"

>>> toNamedSchema (Proxy :: Proxy Day) ^. name
Just "Day"
>>> encode (toNamedSchema (Proxy :: Proxy Day) ^. schema)
"{\"format\":\"date\",\"type\":\"string\"}"

Get type's schema name according to its ToSchema instance.

>>> schemaName (Proxy :: Proxy Int)
Nothing

>>> schemaName (Proxy :: Proxy UTCTime)
Just "UTCTime"

Convert a type into a schema.

>>> encode $ toSchema (Proxy :: Proxy Int8)
"{\"maximum\":127,\"minimum\":-128,\"type\":\"integer\"}"

>>> encode $ toSchema (Proxy :: Proxy [Day])
"{\"items\":{\"$ref\":\"#/definitions/Day\"},\"type\":\"array\"}"

Convert a type into a referenced schema if possible. Only named schemas can be referenced, nameless schemas are inlined.

>>> encode $ toSchemaRef (Proxy :: Proxy Integer)
"{\"type\":\"integer\"}"

>>> encode $ toSchemaRef (Proxy :: Proxy Day)
"{\"$ref\":\"#/definitions/Day\"}"

Convert a type into a referenced schema if possible and declare all used schema definitions. Only named schemas can be referenced, nameless schemas are inlined.

Schema definitions are typically declared for every referenced schema. If declareSchemaRef returns a reference, a corresponding schema will be declared (regardless of whether it is recusive or not).

Inline any referenced schema if its name satisfies given predicate.

NOTE: if a referenced schema is not found in definitions the predicate is ignored and schema stays referenced.

WARNING: inlineSchemasWhen will produce infinite schemas when inlining recursive schemas.

Inline any referenced schema if its name is in the given list.

NOTE: if a referenced schema is not found in definitions it stays referenced even if it appears in the list of names.

WARNING: inlineSchemas will produce infinite schemas when inlining recursive schemas.

Inline all schema references for which the definition can be found in Definitions.

WARNING: inlineAllSchemas will produce infinite schemas when inlining recursive schemas.

Convert a type into a schema without references.

>>> encode $ toInlinedSchema (Proxy :: Proxy [Day])
"{\"items\":{\"format\":\"date\",\"type\":\"string\"},\"type\":\"array\"}"

WARNING: toInlinedSchema will produce infinite schema when inlining recursive schemas.

Inline all non-recursive schemas for which the definition can be found in Definitions.

Default schema for binary data (any sequence of octets).

Default schema for binary data (base64 encoded).

Default schema for password string. "password" format is used to hint UIs the input needs to be obscured.

Make an unrestrictive sketch of a Schema based on a ToJSON instance. Produced schema can be used for further refinement.

>>> encode $ sketchSchema "hello"
"{\"example\":\"hello\",\"type\":\"string\"}"

>>> encode $ sketchSchema (1, 2, 3)
"{\"example\":[1,2,3],\"items\":{\"type\":\"number\"},\"type\":\"array\"}"

>>> encode $ sketchSchema ("Jack", 25)
"{\"example\":[\"Jack\",25],\"items\":[{\"type\":\"string\"},{\"type\":\"number\"}],\"type\":\"array\"}"

>>> data Person = Person { name :: String, age :: Int } deriving (Generic)
>>> instance ToJSON Person
>>> encode $ sketchSchema (Person "Jack" 25)
"{\"example\":{\"age\":25,\"name\":\"Jack\"},\"required\":[\"age\",\"name\"],\"type\":\"object\",\"properties\":{\"age\":{\"type\":\"number\"},\"name\":{\"type\":\"string\"}}}"

Make a restrictive sketch of a Schema based on a ToJSON instance. Produced schema uses as much constraints as possible.

>>> encode $ sketchStrictSchema "hello"
"{\"maxLength\":5,\"pattern\":\"hello\",\"minLength\":5,\"type\":\"string\",\"enum\":[\"hello\"]}"

>>> encode $ sketchStrictSchema (1, 2, 3)
"{\"minItems\":3,\"uniqueItems\":true,\"items\":[{\"maximum\":1,\"minimum\":1,\"multipleOf\":1,\"type\":\"number\",\"enum\":[1]},{\"maximum\":2,\"minimum\":2,\"multipleOf\":2,\"type\":\"number\",\"enum\":[2]},{\"maximum\":3,\"minimum\":3,\"multipleOf\":3,\"type\":\"number\",\"enum\":[3]}],\"maxItems\":3,\"type\":\"array\",\"enum\":[[1,2,3]]}"

>>> encode $ sketchStrictSchema ("Jack", 25)
"{\"minItems\":2,\"uniqueItems\":true,\"items\":[{\"maxLength\":4,\"pattern\":\"Jack\",\"minLength\":4,\"type\":\"string\",\"enum\":[\"Jack\"]},{\"maximum\":25,\"minimum\":25,\"multipleOf\":25,\"type\":\"number\",\"enum\":[25]}],\"maxItems\":2,\"type\":\"array\",\"enum\":[[\"Jack\",25]]}"

>>> data Person = Person { name :: String, age :: Int } deriving (Generic)
>>> instance ToJSON Person
>>> encode $ sketchStrictSchema (Person "Jack" 25)
"{\"minProperties\":2,\"required\":[\"age\",\"name\"],\"maxProperties\":2,\"type\":\"object\",\"enum\":[{\"age\":25,\"name\":\"Jack\"}],\"properties\":{\"age\":{\"maximum\":25,\"minimum\":25,\"multipleOf\":25,\"type\":\"number\",\"enum\":[25]},\"name\":{\"maxLength\":4,\"pattern\":\"Jack\",\"minLength\":4,\"type\":\"string\",\"enum\":[\"Jack\"]}}}"

Default schema for Bounded, Integral types.

>>> encode $ toSchemaBoundedIntegral (Proxy :: Proxy Int16)
"{\"maximum\":32767,\"minimum\":-32768,\"type\":\"integer\"}"

Default generic named schema for Bounded, Integral types.

A configurable generic Schema creator.

A configurable generic NamedSchema creator. This function applied to defaultSchemaOptions is used as the default for declareNamedSchema when the type is an instance of Generic.

Lift a plain ParamSchema into a model NamedSchema.

Lift a plain ParamSchema into a model Schema.