Attribute Macro async_graphql::Subscription[][src]

#[Subscription]
Expand description

Define a GraphQL subscription

See also the Book.

The field function is a synchronization function that performs filtering. When true is returned, the message is pushed to the client. The second parameter is the type of the field. Starting with the third parameter is one or more filtering conditions, The filter condition is the parameter of the field. The filter function should be synchronous.

Macro parameters

AttributedescriptionTypeOptional
nameObject namestringY
rename_fieldsRename all the fields according to the given case convention. The possible values are “lowercase”, “UPPERCASE”, “PascalCase”, “camelCase”, “snake_case”, “SCREAMING_SNAKE_CASE”.stringY
rename_argsRename all the arguments according to the given case convention. The possible values are “lowercase”, “UPPERCASE”, “PascalCase”, “camelCase”, “snake_case”, “SCREAMING_SNAKE_CASE”.stringY
extendsAdd fields to an entity that’s defined in another serviceboolY
use_type_descriptionSpecifies that the description of the type is on the type declaration. Description(derive.Description.html)boolY

Field parameters

AttributedescriptionTypeOptional
nameField namestringY
deprecationField deprecatedboolY
deprecationField deprecation reasonstringY
guardField of guardGuardY
visibleIf false, it will not be displayed in introspection. See also the Book.boolY
visibleCall the specified function. If the return value is false, it will not be displayed in introspection.stringY
secretMark this field as a secret, it will not output the actual value in the log.boolY

Field argument parameters

AttributedescriptionTypeOptional
nameArgument namestringY
descArgument descriptionstringY
defaultUse Default::default for default valuenoneY
defaultArgument default valueliteralY
default_withExpression to generate default valuecode stringY
validatorInput value validatorInputValueValidatorY
visibleIf false, it will not be displayed in introspection. See also the Book.boolY
visibleCall the specified function. If the return value is false, it will not be displayed in introspection.stringY

Examples

use async_graphql::*;
use futures_util::stream::{Stream, StreamExt};

struct SubscriptionRoot;

#[Subscription]
impl SubscriptionRoot {
    async fn value(&self, condition: i32) -> impl Stream<Item = i32> {
        // Returns the number from 0 to `condition`.
        futures_util::stream::iter(0..condition)
    }
}