Safe Haskell	None
Language	Haskell2010

GraphQL

Contents

Running queries
Preparing queries then running them

Description

Interface for GraphQL API.

Note: This module is highly subject to change. We're still figuring where to draw the lines and what to expose.

Synopsis

Running queries

interpretQuery Source #

Arguments

:: (Applicative m, HasResolver m api, HasObjectDefinition api)
=> Handler m api	Handler for the query. This links the query to the code you've written to handle it.
-> Text	The text of a query document. Will be parsed and then executed.
-> Maybe Name	An optional name for the operation within document to run. If `Nothing`, execute the only operation in the document. If `Just "something"`, execute the query or mutation named `"something"`.
-> VariableValues	Values for variables defined in the query document. A map of `Variable` to `Value`.
-> m Response	The outcome of running the query.

Interpet a GraphQL query.

Compiles then executes a GraphQL query.

interpretAnonymousQuery Source #

Arguments

:: (Applicative m, HasResolver m api, HasObjectDefinition api)
=> Handler m api	Handler for the anonymous query.
-> Text	The text of the anonymous query. Should defined only a single, unnamed query operation.
-> m Response	The result of running the query.

Interpret an anonymous GraphQL query.

Anonymous queries have no name and take no variables.

data Response Source #

GraphQL response.

A GraphQL response must:

be a map
have a "data" key iff the operation executed
have an "errors" key iff the operation encountered errors
not include "data" if operation failed before execution (e.g. syntax errors, validation errors, missing info)
not have keys other than "data", "errors", and "extensions"

Other interesting things:

Doesn't have to be JSON, but does have to have maps, strings, lists, and null
Can also support bool, int, enum, and float
Value of "extensions" must be a map

"data" must be null if an error was encountered during execution that prevented a valid response.

"errors"

must be a non-empty list
each error is a map with "message", optionally "locations" key with list of locations
locations are maps with 1-indexed "line" and "column" keys.

Constructors

Success Object
PreExecutionFailure Errors
ExecutionFailure Errors
PartialSuccess Object Errors

Instances

Eq Response Source #
Methods (==) :: Response -> Response -> Bool # (/=) :: Response -> Response -> Bool #
Ord Response Source #
Methods compare :: Response -> Response -> Ordering # (<) :: Response -> Response -> Bool # (<=) :: Response -> Response -> Bool # (>) :: Response -> Response -> Bool # (>=) :: Response -> Response -> Bool # max :: Response -> Response -> Response # min :: Response -> Response -> Response #
Show Response Source #
Methods showsPrec :: Int -> Response -> ShowS # show :: Response -> String # showList :: [Response] -> ShowS #
ToJSON Response Source #
Methods toJSON :: Response -> Value # toEncoding :: Response -> Encoding # toJSONList :: [Response] -> Value # toEncodingList :: [Response] -> Encoding #
ToValue Response Source #
Methods toValue :: Response -> Value' ConstScalar Source #

Preparing queries then running them

makeSchema :: forall api. HasObjectDefinition api => Either QueryError Schema Source #

Create a GraphQL schema.

compileQuery :: Schema -> Text -> Either QueryError (QueryDocument VariableValue) Source #

Turn some text into a valid query document.

executeQuery Source #

Arguments

:: (HasResolver m api, Applicative m, HasObjectDefinition api)
=> Handler m api	Handler for the query. This links the query to the code you've written to handle it.
-> QueryDocument VariableValue	A validated query document. Build one with `compileQuery`.
-> Maybe Name	An optional name. If `Nothing`, then executes the only operation in the query. If `Just "something"`, executes the query named @"something".
-> VariableValues	Values for variables defined in the query document. A map of `Variable` to `Value`.
-> m Response	The outcome of running the query.

Execute a GraphQL query.

data QueryError Source #

Errors that can happen while processing a query document.

Instances

Eq QueryError Source #
Methods (==) :: QueryError -> QueryError -> Bool # (/=) :: QueryError -> QueryError -> Bool #
Show QueryError Source #
Methods showsPrec :: Int -> QueryError -> ShowS # show :: QueryError -> String # showList :: [QueryError] -> ShowS #
GraphQLError QueryError Source #
Methods formatError :: QueryError -> Text Source # toError :: QueryError -> Error Source #

data Schema Source #

An entire GraphQL schema.

This is very much a work in progress. Currently, the only thing we provide is a dictionary mapping type names to their definitions.

Instances

Eq Schema Source #
Methods (==) :: Schema -> Schema -> Bool # (/=) :: Schema -> Schema -> Bool #
Ord Schema Source #
Methods compare :: Schema -> Schema -> Ordering # (<) :: Schema -> Schema -> Bool # (<=) :: Schema -> Schema -> Bool # (>) :: Schema -> Schema -> Bool # (>=) :: Schema -> Schema -> Bool # max :: Schema -> Schema -> Schema # min :: Schema -> Schema -> Schema #
Show Schema Source #
Methods showsPrec :: Int -> Schema -> ShowS # show :: Schema -> String # showList :: [Schema] -> ShowS #

type VariableValues = Map Variable Value Source #

A map of variables to their values.

In GraphQL the variable values are not part of the query itself, they are instead passed in through a separate channel. Create a VariableValues from this other channel and pass it to substituteVariables.

GraphQL allows the values of variables to be specified, but doesn't provide a way for doing so in the language.

type Value = Value' ConstScalar Source #

A GraphQL value which contains no variables.