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::util::to_camel_case;
pub use crate::ast::Definition;
pub use crate::ast::Document;
pub use crate::executor::Applies;
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::LookAheadArgument;
pub use crate::executor::LookAheadMethods;
pub use crate::executor::LookAheadSelection;
pub use crate::executor::LookAheadValue;
pub use crate::executor::OwnedExecutor;
pub use crate::executor::Registry;
pub use crate::executor::ValuesStream;
pub use crate::executor::Variables;
pub use crate::parser::ParseError;
pub use crate::parser::Spanning;
pub use crate::validation::RuleError;
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
- A Object value
- Root query node of a schema
- Metadata for a schema
Enums
- 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)
Nullable
can be used in situations where you need to distinguish between an implicitly and explicitly null input value.- 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 implementsGraphQLValue
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 withGraphQLValue
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. - 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 Aliases
- 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 theSend
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.