Operation

An GraphQL operation is a query, mutation or subscription. When you create an operation using the GraphQL extension point, it creates a module. This module has the following module type:

module type Operation = {

include Definition;

module Raw: {

include Definition.Raw;

type t_variables;

};

type t_variables;

let makeVariables: (~exampleVariable: string, unit) => t_variables;

let serializeVariables: t_variables => Raw.t_variables;

}

It includes the Definition module type so everything in Definition is also part of the Operation module type.

Types

Type t_variables

This is the the type of the variables in ReasonML data types.

Data Types

Nullable

Nullable variable values are represented as option. When this types is serialized option's are converted to undefined. Because null is also a valid value, it is not representable in this data type. To set a value explicitly null you can use Raw.t_variables.

Input Objects

Input objects are represented as records. The type is named as t_variables_InputObjectName.

Other data types

Other data types are consistent with the types of t.

Type Raw.t_variables

This is the (no cost) type of the variables. It's a record if there are variables and it's () (unit), if there are no variables.

Data Types

Nullable

Nullable variable values are represented as Js.Nullable.t. It is important to note that there is a difference between Js.Nullable.null and Js.Nullable.undefined. null will be an explicit null, and undefined will act as a missing field. Both are different things in the GraphQL API.

Input Objects

Input objects are represented as records. The type is named as Raw.t_variables_InputObjectName.

Other data types

Other data types are consistent with the types of Raw.t.

Bindings

makeVariables

This is the creator function for Raw.t_variables. Often when you pass variables to a library, that library expects the Raw.t_variables type. You can make this using this function.

let variables = Query.makeVariables(~exampleVariable="something", ());

let result = Query.use(~variables, ())

serializeVariables

If you rather create the variables yourself, you can construct the t_variables record. Because most libraries expect Raw.t_variables, you can serialize the record using this function.

variablesToJson

This will convert Raw.t_variables to Js.Json.t (zero cost binding).