Attribute Macro async_graphql::ComplexObject

#[ComplexObject]

Define a complex GraphQL object for SimpleObject’s complex field resolver.

See also the Book.

Sometimes most of the fields of a GraphQL object simply return the value of the structure member, but a few fields are calculated. Usually we use the Object macro to define such a GraphQL object.

But this can be done more beautifully with the ComplexObject macro. We can use the SimpleObject macro to define some simple fields, and use the ComplexObject macro to define some other fields that need to be calculated.

Macro parameters

Attribute	description	Type	Optional
name	Object name	string	Y
rename_fields	Rename all the fields according to the given case convention. The possible values are “lowercase”, “UPPERCASE”, “PascalCase”, “camelCase”, “snake_case”, “SCREAMING_SNAKE_CASE”.	string	Y
rename_args	Rename all the arguments according to the given case convention. The possible values are “lowercase”, “UPPERCASE”, “PascalCase”, “camelCase”, “snake_case”, “SCREAMING_SNAKE_CASE”.	string	Y

Field parameters

Attribute	description	Type	Optional
skip	Skip this field	bool	Y
name	Field name	string	Y
deprecation	Field deprecated	bool	Y
deprecation	Field deprecation reason	string	Y
cache_control	Field cache control	CacheControl	Y
external	Mark a field as owned by another service. This allows service A to use fields from service B while also knowing at runtime the types of that field.	bool	Y
provides	Annotate the expected returned fieldset from a field on a base type that is guaranteed to be selectable by the gateway.	string	Y
requires	Annotate the required input fieldset from a base type for a resolver. It is used to develop a query plan where the required fields may not be needed by the client, but the service may need additional information from other services.	string	Y
guard	Field of guard	Guard	Y
visible	If false, it will not be displayed in introspection. See also the Book.	bool	Y
visible	Call the specified function. If the return value is false, it will not be displayed in introspection.	string	Y

Examples

use async_graphql::*;

#[derive(SimpleObject)]
#[graphql(complex)] // NOTE: If you want the `ComplexObject` macro to take effect, this `complex` attribute is required.
struct MyObj {
    a: i32,
    b: i32,
}

#[ComplexObject]
impl MyObj {
    async fn c(&self) -> i32 {
        self.a + self.b     
    }
}

struct QueryRoot;

#[Object]
impl QueryRoot {
    async fn obj(&self) -> MyObj {
        MyObj { a: 10, b: 20 }
    }
}

tokio::runtime::Runtime::new().unwrap().block_on(async move {
    let schema = Schema::new(QueryRoot, EmptyMutation, EmptySubscription);
    let res = schema.execute("{ obj { a b c } }").await.into_result().unwrap().data;
    assert_eq!(res, value!({
        "obj": {
            "a": 10,
            "b": 20,
            "c": 30,
        },
    }));
});