Expand description
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.
- Cargo crate
- API Reference
- Book: Guides and Examples
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.
Re-exports
pub use crate::executor::Context;
pub use crate::executor::ExecutionError;
pub use crate::executor::ExecutionResult;
pub use crate::executor::Executor;
pub use crate::executor::FieldError;
pub use crate::executor::FieldResult;
pub use crate::executor::FromContext;
pub use crate::executor::IntoFieldError;
pub use crate::executor::IntoResolvable;
pub use crate::executor::Registry;
pub use crate::executor::ValuesStream;
pub use crate::executor::Variables;
Modules
Resolve the document to values
Utilities for building HTTP endpoints in a library-agnostic manner
Provides GraphQLType implementations for some external types
Marker traits for GraphQL types.
Types used to describe a GraphQL
schema
Query parser and language utilities
Query validation related methods and data structures
Macros
Construct JSON-like values by using JSON syntax
Structs
Field argument container
Utility type to define read-only schemas
Utillity type to define read-only schemas
Represents the result of executing a GraphQL operation (after parsing and validating has been done).
An ID as defined by the GraphQL specification
An argument passed into the query
A selection performed by a query
A Object value
Root query node of a schema
Query validation error
Metadata for a schema
Data structure used to wrap items with start and end markers in the input source
Enums
An enum that describes if a field is available in all types of the interface or only in a certain subtype
The default scalar value representation in juniper
An error that prevented query execution
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.
The desired GraphQL introspection format for the canonical query (https://github.com/graphql/graphql-js/blob/8c96dc8276f2de27b8af9ffbd71a4597d483523f/src/utilities/introspectionQuery.js#L21)
A JSON-like value that can is used as argument in the query execution
Nullable
can be used in situations where you need to distinguish between an implicitly and
explicitly null input value.
Error while parsing a GraphQL query
Entry in a GraphQL selection set
A type literal in the syntax tree
GraphQL type kind
Serializable value returned from query and field execution.
Traits
Conversion of a GraphQLValue
to its trait object.
This trait is used in juniper::graphql_subscription
macro to get stream’s
item type that implements GraphQLValue
from type alias provided
by user.
Parse an unstructured input value into a Rust data type.
Maker trait for GraphQL interfaces.
Extension of GraphQLType
trait with asynchronous subscription execution logic.
Extension of GraphQLValue
trait with asynchronous subscription execution logic.
It should be used with GraphQLValue
in order to implement subscription resolvers on
GraphQL objects.
Primary trait used to expose Rust types in a GraphQL schema.
Extension of GraphQLType
trait with asynchronous queries/mutations resolvers.
Maker trait for GraphQL unions.
Primary trait used to resolve GraphQL values.
Extension of GraphQLValue
trait with asynchronous queries/mutations resolvers.
Set of common methods for ConcreteLookAheadSelection
and LookAheadSelection
.
A trait used to convert a ScalarToken
into a certain scalar value type
A trait marking a type that could be used as internal representation of scalar values in juniper
Single subscription connection.
Global subscription coordinator trait.
Losslessly clones a Rust data type into an InputValue.
Functions
Execute a query in a provided schema
Execute a query synchronously in a provided schema
Execute the reference introspection query in the provided schema
Resolve subscription into ValuesStream
Type Definitions
An owned dynamically typed Future
for use in cases where you can’t
statically type your result or need to add some indirection.
Helper alias for naming trait objects of GraphQLValue
.
Helper alias for naming trait objects of GraphQLValueAsync
.
BoxFuture
, but without the Send
requirement.
The result of converting a string into a scalar value
Attribute Macros
#[graphql_interface]
macro for generating a GraphQL interface implementation for traits
and its implementers.
The object
proc macro is the primary way of defining GraphQL resolvers
that can not be implemented with the GraphQLObject derive.
Expose GraphQL scalars
A proc macro for defining a GraphQL subscription.
#[graphql_union]
macro for deriving a GraphQL union implementation for traits.
Derive Macros
This custom derive macro implements the #[derive(GraphQLScalarValue)] derive.
#[derive(GraphQLUnion)]
macro for deriving a GraphQL union implementation for enums and
structs.