Crate juniper [] [src]

GraphQL

GraphQL is a data query language developed by Facebook intended to serve mobile and web application frontends.

Juniper makes it possible to write GraphQL servers in Rust that are type-safe and blazingly fast. We also try to make declaring and resolving GraphQL schemas as convenient as possible as Rust will allow.

Juniper does not include a web server - instead it provides building blocks to make integration with existing servers straightforward. It optionally provides a pre-built integration for the Iron and Rocket frameworks, including embedded Graphiql for easy debugging.

Getting Started

The best place to get started is the Juniper Book, which contains guides with plenty of examples, covering all features of Juniper.

To get started quickly and get a feel for Juniper, check out the Quickstart section.

For specific information about macros, types and the Juniper api, the API Reference is the best place to look.

You can also check out src/tests/schema.rs to see a complex schema including polymorphism with traits and interfaces. For an example of web framework integration, see the rocket and iron examples folders.

Features

Juniper supports the full GraphQL query language according to the specification, including interfaces, unions, schema introspection, and validations. It does not, however, support the schema language.

As an exception to other GraphQL libraries for other languages, Juniper builds non-null types by default. A field of type Vec<Episode> will be converted into [Episode!]!. The corresponding Rust type for e.g. [Episode] would be Option<Vec<Option<Episode>>>.

Integrations

Data types

Juniper has automatic integration with some very common Rust crates to make building schemas a breeze. The types from these crates will be usable in your Schemas automatically.

Web Frameworks

API Stability

Juniper has not reached 1.0 yet, thus some API instability should be expected.

Reexports

pub use http::graphiql;

Modules

http

Utilities for building HTTP endpoints in a library-agnostic manner

integrations

Provides GraphQLType implementations for some external types

meta

Types used to describe a GraphQL schema

parser

Query parser and language utilities

Macros

graphql_interface

Expose GraphQL interfaces

graphql_object

Expose GraphQL objects

graphql_scalar

Expose GraphQL scalars

graphql_union

Expose GraphQL unions

graphql_value

Construct JSON-like values by using JSON syntax

Structs

Arguments

Field argument container

EmptyMutation

Utility type to define read-only schemas

ExecutionError

Error type for errors that occur during query execution

Executor

Query execution engine

FieldError

Error type for errors that occur during field resolution

ID

An ID as defined by the GraphQL specification

Registry

A type registry used to build schemas

RootNode

Root query node of a schema

RuleError

Query validation error

Enums

GraphQLError

An error that prevented query execution

InputValue

A JSON-like value that can be passed into the query execution, either out-of-band, or in-band as default variable values. These are not constant and might contain variables.

Selection

Entry in a GraphQL selection set

Type

A type literal in the syntax tree

TypeKind

GraphQL type kind

Value

Serializable value returned from query and field execution.

Traits

Context

Marker trait for types that can act as context objects for GraphQL types.

FromContext

Conversion trait for context types

FromInputValue

Parse an unstructured input value into a Rust data type.

GraphQLType

Primary trait used to expose Rust types in a GraphQL schema

ToInputValue

Losslessly clones a Rust data type into an InputValue.

Functions

execute

Execute a query in a provided schema

Type Definitions

ExecutionResult

The result of resolving an unspecified field

FieldResult

The result of resolving the value of a field of type T

Variables

The map of variables used for substitution during query execution