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< h1 id = "enums" > < a class = "header" href = "#enums" > Enums< / a > < / h1 >
< blockquote >
< p > < a href = "https://spec.graphql.org/October2021#sec-Enums" > GraphQL enum< / a > types, like < a href = "https://spec.graphql.org/October2021#sec-Scalars" > scalar< / a > types, also represent leaf values in a GraphQL type system. However < a href = "https://spec.graphql.org/October2021#sec-Enums" > enum< / a > types describe the set of possible values.< / p >
< p > < a href = "https://spec.graphql.org/October2021#sec-Enums" > Enums< / a > are not references for a numeric value, but are unique values in their own right. They may serialize as a string: the name of the represented value.< / p >
< / blockquote >
2024-03-20 11:39:21 -05:00
< p > With < a href = "https://docs.rs/juniper" > Juniper< / a > a < a href = "https://spec.graphql.org/October2021#sec-Enums" > GraphQL enum< / a > may be defined by using the < a href = "https://docs.rs/juniper/0.16.0/juniper/derive.GraphQLEnum.html" > < code > #[derive(GraphQLEnum)]< / code > < / a > attribute on a < a href = "https://doc.rust-lang.org/reference/items/enumerations.html" > Rust enum< / a > as long as its variants do not have any fields:< / p >
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< pre > < pre class = "playground" > < code class = "language-rust edition2021" > < span class = "boring" > extern crate juniper;
< / span > < span class = "boring" > use juniper::GraphQLEnum;
< / span > < span class = "boring" >
< / span > #[derive(GraphQLEnum)]
enum Episode {
NewHope,
Empire,
Jedi,
}
< span class = "boring" >
< / span > < span class = "boring" > fn main() {}< / span > < / code > < / pre > < / pre >
< h3 id = "renaming" > < a class = "header" href = "#renaming" > Renaming< / a > < / h3 >
< p > By default, < a href = "https://doc.rust-lang.org/reference/items/enumerations.html" > enum< / a > variants are converted from < a href = "https://www.rust-lang.org" > Rust< / a > 's standard < code > PascalCase< / code > naming convention into < a href = "https://graphql.org" > GraphQL< / a > 's < code > SCREAMING_SNAKE_CASE< / code > convention:< / p >
< pre > < pre class = "playground" > < code class = "language-rust edition2021" > < span class = "boring" > extern crate juniper;
< / span > < span class = "boring" > use juniper::GraphQLEnum;
< / span > < span class = "boring" >
< / span > #[derive(GraphQLEnum)]
enum Episode {
NewHope, // exposed as `NEW_HOPE` in GraphQL schema
Empire, // exposed as `EMPIRE` in GraphQL schema
Jedi, // exposed as `JEDI` in GraphQL schema
}
< span class = "boring" >
< / span > < span class = "boring" > fn main() {}< / span > < / code > < / pre > < / pre >
< p > We can override the name by using the < code > #[graphql(name = "...")]< / code > attribute:< / p >
< pre > < pre class = "playground" > < code class = "language-rust edition2021" > < span class = "boring" > extern crate juniper;
< / span > < span class = "boring" > use juniper::GraphQLEnum;
< / span > < span class = "boring" >
< / span > #[derive(GraphQLEnum)]
#[graphql(name = "WrongEpisode")] // now exposed as `WrongEpisode` in GraphQL schema
enum Episode {
#[graphql(name = "LAST_HOPE")]
NewHope, // exposed as `LAST_HOPE` in GraphQL schema
Empire,
Jedi,
}
< span class = "boring" >
< / span > < span class = "boring" > fn main() {}< / span > < / code > < / pre > < / pre >
< p > Or provide a different renaming policy for all the < a href = "https://doc.rust-lang.org/reference/items/enumerations.html" > enum< / a > variants:< / p >
< pre > < pre class = "playground" > < code class = "language-rust edition2021" > < span class = "boring" > extern crate juniper;
< / span > < span class = "boring" > use juniper::GraphQLEnum;
< / span > < span class = "boring" >
< / span > #[derive(GraphQLEnum)]
#[graphql(rename_all = "none")] // disables any renaming
enum Episode {
NewHope, // exposed as `NewHope` in GraphQL schema
Empire, // exposed as `Empire` in GraphQL schema
Jedi, // exposed as `Jedi` in GraphQL schema
}
< span class = "boring" >
< / span > < span class = "boring" > fn main() {}< / span > < / code > < / pre > < / pre >
< blockquote >
< p > < strong > TIP< / strong > : Supported policies are: < code > SCREAMING_SNAKE_CASE< / code > , < code > camelCase< / code > and < code > none< / code > (disables any renaming).< / p >
< / blockquote >
< h3 id = "documentation-and-deprecation" > < a class = "header" href = "#documentation-and-deprecation" > Documentation and deprecation< / a > < / h3 >
< p > Just like when < a href = "objects/index.html#documentation" > defining GraphQL objects< / a > , the < a href = "https://spec.graphql.org/October2021#sec-Enums" > GraphQL enum< / a > type and its values could be < a href = "https://spec.graphql.org/October2021#sec-Descriptions" > documented< / a > and < a href = "https://spec.graphql.org/October2021#sec--deprecated" > deprecated< / a > via < code > #[graphql(description = "...")]< / code > and < code > #[graphql(deprecated = "...")]< / code > /< a href = "https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-deprecated-attribute" > < code > #[deprecated]< / code > < / a > attributes:< / p >
< pre > < pre class = "playground" > < code class = "language-rust edition2021" > < span class = "boring" > extern crate juniper;
< / span > < span class = "boring" > use juniper::GraphQLEnum;
< / span > < span class = "boring" >
< / span > /// This doc comment is visible only in Rust API docs.
#[derive(GraphQLEnum)]
#[graphql(description = "An episode of Star Wars")]
enum StarWarsEpisode {
/// This doc comment is visible only in Rust API docs.
#[graphql(description = "This description is visible only in GraphQL schema.")]
NewHope,
/// This doc comment is visible only in Rust API docs.
#[graphql(desc = "Arguably the best one in the trilogy.")]
// ^^^^ shortcut for a `description` argument
Empire,
/// This doc comment is visible in both Rust API docs and GraphQL schema
/// descriptions.
Jedi,
#[deprecated(note = "Only visible in Rust.")]
#[graphql(deprecated = "We don't really talk about this one.")]
// ^^^^^^^^^^ takes precedence over Rust's `#[deprecated]` attribute
ThePhantomMenace, // has no description in GraphQL schema
}
< span class = "boring" >
< / span > < span class = "boring" > fn main() {}< / span > < / code > < / pre > < / pre >
< blockquote >
< p > < strong > NOTE< / strong > : Only < a href = "https://spec.graphql.org/October2021#sec-Objects" > GraphQL object< / a > /< a href = "https://spec.graphql.org/October2021#sec-Interfaces" > interface< / a > fields and < a href = "https://spec.graphql.org/October2021#sec-Enums" > GraphQL enum< / a > values can be < a href = "https://spec.graphql.org/October2021#sec--deprecated" > deprecated< / a > .< / p >
< / blockquote >
< h3 id = "ignoring" > < a class = "header" href = "#ignoring" > Ignoring< / a > < / h3 >
< p > By default, all < a href = "https://doc.rust-lang.org/reference/items/enumerations.html" > enum< / a > variants are included in the generated < a href = "https://spec.graphql.org/October2021#sec-Enums" > GraphQL enum< / a > type as values. To prevent including a specific variant, annotate it with the < code > #[graphql(ignore)]< / code > attribute:< / p >
< pre > < pre class = "playground" > < code class = "language-rust edition2021" > < span class = "boring" > #![allow(dead_code)]
< / span > < span class = "boring" > extern crate juniper;
< / span > < span class = "boring" > use juniper::GraphQLEnum;
< / span > < span class = "boring" >
< / span > #[derive(GraphQLEnum)]
enum Episode< T> {
NewHope,
Empire,
Jedi,
#[graphql(ignore)]
Legends(T), // cannot be queried from GraphQL
#[graphql(skip)]
// ^^^^ alternative naming, up to your preference
CloneWars(T), // cannot be queried from GraphQL
}
< span class = "boring" >
< / span > < span class = "boring" > fn main() {}< / span > < / code > < / pre > < / pre >
< blockquote >
2024-03-20 11:39:21 -05:00
< p > < strong > TIP< / strong > : See more available features in the API docs of the < a href = "https://docs.rs/juniper/0.16.0/juniper/derive.GraphQLEnum.html" > < code > #[derive(GraphQLEnum)]< / code > < / a > attribute.< / p >
2024-03-20 11:02:08 -05:00
< / blockquote >
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