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<ol class="chapter"><li class="chapter-item expanded "><a href="../index.html"><strong aria-hidden="true">1.</strong> Introduction</a></li><li class="chapter-item expanded "><a href="../quickstart.html"><strong aria-hidden="true">2.</strong> Quickstart</a></li><li class="chapter-item expanded "><a href="../types/index.html"><strong aria-hidden="true">3.</strong> Type System</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../types/objects/defining_objects.html"><strong aria-hidden="true">3.1.</strong> Defining objects</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../types/objects/complex_fields.html"><strong aria-hidden="true">3.1.1.</strong> Complex fields</a></li><li class="chapter-item expanded "><a href="../types/objects/using_contexts.html"><strong aria-hidden="true">3.1.2.</strong> Using contexts</a></li><li class="chapter-item expanded "><a href="../types/objects/error_handling.html"><strong aria-hidden="true">3.1.3.</strong> Error handling</a></li></ol></li><li class="chapter-item expanded "><a href="../types/other-index.html"><strong aria-hidden="true">3.2.</strong> Other types</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../types/enums.html"><strong aria-hidden="true">3.2.1.</strong> Enums</a></li><li class="chapter-item expanded "><a href="../types/interfaces.html" class="active"><strong aria-hidden="true">3.2.2.</strong> Interfaces</a></li><li class="chapter-item expanded "><a href="../types/input_objects.html"><strong aria-hidden="true">3.2.3.</strong> Input objects</a></li><li class="chapter-item expanded "><a href="../types/scalars.html"><strong aria-hidden="true">3.2.4.</strong> Scalars</a></li><li class="chapter-item expanded "><a href="../types/unions.html"><strong aria-hidden="true">3.2.5.</strong> Unions</a></li></ol></li></ol></li><li class="chapter-item expanded "><a href="../schema/schemas_and_mutations.html"><strong aria-hidden="true">4.</strong> Schemas and mutations</a></li><li class="chapter-item expanded "><a href="../servers/index.html"><strong aria-hidden="true">5.</strong> Adding A Server</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../servers/official.html"><strong aria-hidden="true">5.1.</strong> Official Server Integrations</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../servers/warp.html"><strong aria-hidden="true">5.1.1.</strong> Warp</a></li><li class="chapter-item expanded "><a href="../servers/rocket.html"><strong aria-hidden="true">5.1.2.</strong> Rocket</a></li><li class="chapter-item expanded "><a href="../servers/hyper.html"><strong aria-hidden="true">5.1.3.</strong> Hyper</a></li></ol></li><li class="chapter-item expanded "><a href="../servers/third-party.html"><strong aria-hidden="true">5.2.</strong> Third Party Integrations</a></li></ol></li><li class="chapter-item expanded "><a href="../advanced/index.html"><strong aria-hidden="true">6.</strong> Advanced Topics</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../advanced/introspection.html"><strong aria-hidden="true">6.1.</strong> Introspection</a></li><li class="chapter-item expanded "><a href="../advanced/non_struct_objects.html"><strong aria-hidden="true">6.2.</strong> Non-struct objects</a></li><li class="chapter-item expanded "><a href="../advanced/implicit_and_explicit_null.html"><strong aria-hidden="true">6.3.</strong> Implicit and explicit null</a></li><li class="chapter-item expanded "><a href="../advanced/objects_and_generics.html"><strong aria-hidden="true">6.4.</strong> Objects and generics</a></li><li class="chapter-item expanded "><a href="../advanced/multiple_ops_per_request.html"><strong aria-hidden="true">6.5.</strong> Multiple operations per request</a></li><li class="chapter-item expanded "><a href="../advanced/dataloaders.html"><strong aria-hidden="true">6.6.</strong> Dataloaders</a></li><li class="chapter-item expanded "><a href="../advanced/subscriptions.html"><strong aria-hidden="true">6.7.</strong> Subscriptions</a></li></ol></li></ol>
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<h1 id="interfaces"><a class="header" href="#interfaces">Interfaces</a></h1>
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<p><a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interfaces</a> map well to interfaces known from common object-oriented languages such as Java or C#, but Rust, unfortunately, has no concept that maps perfectly to them. The nearest analogue of <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interfaces</a> are Rust traits, and the main difference is that in GraphQL an <a href="https://spec.graphql.org/October2021#sec-Interfaces">interface type</a> serves both as an <em>abstraction</em> and a <em>boxed value (downcastable to concrete implementers)</em>, while in Rust, a trait is an <em>abstraction only</em> and <em>to represent such a boxed value a separate type is required</em>, like enum or trait object, because Rust trait doesn't represent a type itself, and so can have no values. This difference imposes some unintuitive and non-obvious corner cases when we try to express <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interfaces</a> in Rust, but on the other hand gives you full control over which type is backing your interface, and how it's resolved.</p>
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<p>For implementing <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interfaces</a> Juniper provides the <code>#[graphql_interface]</code> macro.</p>
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<h2 id="traits"><a class="header" href="#traits">Traits</a></h2>
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<p>Defining a trait is mandatory for defining a <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interface</a>, because this is the <em>obvious</em> way we describe an <em>abstraction</em> in Rust. All <a href="https://spec.graphql.org/October2021#sec-Interfaces">interface</a> fields are defined as computed ones via trait methods.</p>
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<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
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</span>use juniper::graphql_interface;
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#[graphql_interface]
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trait Character {
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fn id(&self) -> &str;
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}
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<span class="boring">
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</span><span class="boring">fn main() {}</span></code></pre></pre>
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<p>However, to return values of such <a href="https://spec.graphql.org/October2021#sec-Interfaces">interface</a>, we should provide its implementers and the Rust type representing a <em>boxed value of this trait</em>. The last one can be represented in two flavors: enum and <a href="https://doc.rust-lang.org/reference/types/trait-object.html">trait object</a>.</p>
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<h3 id="enum-values-default"><a class="header" href="#enum-values-default">Enum values (default)</a></h3>
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<p>By default, Juniper generates an enum representing the values of the defined <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interface</a>, and names it straightforwardly, <code>{Interface}Value</code>.</p>
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<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
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</span>use juniper::{graphql_interface, GraphQLObject};
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#[graphql_interface(for = [Human, Droid])] // enumerating all implementers is mandatory
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trait Character {
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fn id(&self) -> &str;
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}
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#[derive(GraphQLObject)]
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#[graphql(impl = CharacterValue)] // notice enum name, NOT trait name
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struct Human {
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id: String,
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}
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#[derive(GraphQLObject)]
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#[graphql(impl = CharacterValue)]
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struct Droid {
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id: String,
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}
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<span class="boring">
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</span><span class="boring">fn main() {}</span></code></pre></pre>
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<p>Also, enum name can be specified explicitly, if desired.</p>
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<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
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</span>use juniper::{graphql_interface, GraphQLObject};
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#[graphql_interface(enum = CharacterInterface, for = Human)]
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trait Character {
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fn id(&self) -> &str;
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}
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#[derive(GraphQLObject)]
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#[graphql(impl = CharacterInterface)]
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struct Human {
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id: String,
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home_planet: String,
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}
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<span class="boring">
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</span><span class="boring">fn main() {}</span></code></pre></pre>
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<h3 id="interfaces-implementing-other-interfaces"><a class="header" href="#interfaces-implementing-other-interfaces">Interfaces implementing other interfaces</a></h3>
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<p>GraphQL allows implementing interfaces on other interfaces in addition to objects.</p>
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<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
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</span>use juniper::{graphql_interface, graphql_object, ID};
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#[graphql_interface(for = [HumanValue, Luke])]
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struct Node {
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id: ID,
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}
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#[graphql_interface(impl = NodeValue, for = Luke)]
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struct Human {
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id: ID,
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home_planet: String,
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}
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struct Luke {
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id: ID,
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}
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#[graphql_object(impl = [HumanValue, NodeValue])]
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impl Luke {
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fn id(&self) -> &ID {
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&self.id
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}
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// As `String` and `&str` aren't distinguished by
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// GraphQL spec, you can use them interchangeably.
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// Same is applied for `Cow<'a, str>`.
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// ⌄⌄⌄⌄⌄⌄⌄⌄⌄⌄⌄⌄
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fn home_planet() -> &'static str {
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"Tatooine"
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}
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}
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<span class="boring">
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</span><span class="boring">fn main() {}</span></code></pre></pre>
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<blockquote>
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<p><strong>NOTE:</strong> Every interface has to specify all other interfaces/objects it implements or implemented for. Missing one of <code>for = </code> or <code>impl = </code> attributes is a compile-time error.</p>
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</blockquote>
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<pre><code class="language-compile_fail"># extern crate juniper;
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use juniper::{graphql_interface, GraphQLObject};
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#[derive(GraphQLObject)]
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pub struct ObjA {
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id: String,
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}
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#[graphql_interface(for = ObjA)]
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// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at
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// 'Failed to implement interface `Character` on `ObjA`: missing interface reference in implementer's `impl` attribute.'
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struct Character {
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id: String,
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}
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fn main() {}
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||
</code></pre>
|
||
<h3 id="graphql-subtyping-and-additional-nullable-fields"><a class="header" href="#graphql-subtyping-and-additional-nullable-fields">GraphQL subtyping and additional <code>null</code>able fields</a></h3>
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<p>GraphQL allows implementers (both objects and other interfaces) to return "subtypes" instead of an original value. Basically, this allows you to impose additional bounds on the implementation.</p>
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<p>Valid "subtypes" are:</p>
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<ul>
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<li>interface implementer instead of an interface itself:
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||
<ul>
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<li><code>I implements T</code> in place of a <code>T</code>;</li>
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<li><code>Vec<I implements T></code> in place of a <code>Vec<T></code>.</li>
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</ul>
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||
</li>
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<li>non-null value in place of a nullable:
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<ul>
|
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<li><code>T</code> in place of a <code>Option<T></code>;</li>
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<li><code>Vec<T></code> in place of a <code>Vec<Option<T>></code>.</li>
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</ul>
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||
</li>
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||
</ul>
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<p>These rules are recursively applied, so <code>Vec<Vec<I implements T>></code> is a valid "subtype" of a <code>Option<Vec<Option<Vec<Option<T>>>>></code>.</p>
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<p>Also, GraphQL allows implementers to add <code>null</code>able fields, which aren't present on an original interface.</p>
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||
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
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</span>use juniper::{graphql_interface, graphql_object, ID};
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|
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#[graphql_interface(for = [HumanValue, Luke])]
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struct Node {
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id: ID,
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}
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#[graphql_interface(for = HumanConnectionValue)]
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struct Connection {
|
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nodes: Vec<NodeValue>,
|
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}
|
||
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#[graphql_interface(impl = NodeValue, for = Luke)]
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struct Human {
|
||
id: ID,
|
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home_planet: String,
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||
}
|
||
|
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#[graphql_interface(impl = ConnectionValue)]
|
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struct HumanConnection {
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nodes: Vec<HumanValue>,
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// ^^^^^^^^^^ notice not `NodeValue`
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// This can happen, because every `Human` is a `Node` too, so we are just
|
||
// imposing additional bounds, which still can be resolved with
|
||
// `... on Connection { nodes }`.
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||
}
|
||
|
||
struct Luke {
|
||
id: ID,
|
||
}
|
||
|
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#[graphql_object(impl = [HumanValue, NodeValue])]
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impl Luke {
|
||
fn id(&self) -> &ID {
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&self.id
|
||
}
|
||
|
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fn home_planet(language: Option<String>) -> &'static str {
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// ^^^^^^^^^^^^^^
|
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// Notice additional `null`able field, which is missing on `Human`.
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// Resolving `...on Human { homePlanet }` will provide `None` for this
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// argument.
|
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match language.as_deref() {
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None | Some("en") => "Tatooine",
|
||
Some("ko") => "타투인",
|
||
_ => todo!(),
|
||
}
|
||
}
|
||
}
|
||
<span class="boring">
|
||
</span><span class="boring">fn main() {}</span></code></pre></pre>
|
||
<p>Violating GraphQL "subtyping" or additional nullable field rules is a compile-time error.</p>
|
||
<pre><code class="language-compile_fail"># extern crate juniper;
|
||
use juniper::{graphql_interface, graphql_object};
|
||
|
||
pub struct ObjA {
|
||
id: String,
|
||
}
|
||
|
||
#[graphql_object(impl = CharacterValue)]
|
||
impl ObjA {
|
||
fn id(&self, is_present: bool) -> &str {
|
||
// ^^ the evaluated program panicked at
|
||
// 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!`
|
||
// isn't present on the interface and so has to be nullable.'
|
||
is_present.then_some(&self.id).unwrap_or("missing")
|
||
}
|
||
}
|
||
|
||
#[graphql_interface(for = ObjA)]
|
||
struct Character {
|
||
id: String,
|
||
}
|
||
#
|
||
# fn main() {}
|
||
</code></pre>
|
||
<pre><code class="language-compile_fail"># extern crate juniper;
|
||
use juniper::{graphql_interface, GraphQLObject};
|
||
|
||
#[derive(GraphQLObject)]
|
||
#[graphql(impl = CharacterValue)]
|
||
pub struct ObjA {
|
||
id: Vec<String>,
|
||
// ^^ the evaluated program panicked at
|
||
// 'Failed to implement interface `Character` on `ObjA`: Field `id`: implementer is expected to return a subtype of
|
||
// interface's return object: `[String!]!` is not a subtype of `String!`.'
|
||
}
|
||
|
||
#[graphql_interface(for = ObjA)]
|
||
struct Character {
|
||
id: String,
|
||
}
|
||
#
|
||
# fn main() {}
|
||
</code></pre>
|
||
<h3 id="ignoring-trait-methods"><a class="header" href="#ignoring-trait-methods">Ignoring trait methods</a></h3>
|
||
<p>We may want to omit some trait methods to be assumed as <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interface</a> fields and ignore them.</p>
|
||
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
|
||
</span>use juniper::{graphql_interface, GraphQLObject};
|
||
|
||
#[graphql_interface(for = Human)]
|
||
trait Character {
|
||
fn id(&self) -> &str;
|
||
|
||
#[graphql(ignore)] // or `#[graphql(skip)]`, your choice
|
||
fn ignored(&self) -> u32 { 0 }
|
||
}
|
||
|
||
#[derive(GraphQLObject)]
|
||
#[graphql(impl = CharacterValue)]
|
||
struct Human {
|
||
id: String,
|
||
}
|
||
<span class="boring">
|
||
</span><span class="boring">fn main() {}</span></code></pre></pre>
|
||
<h3 id="fields-arguments-and-interface-customization"><a class="header" href="#fields-arguments-and-interface-customization">Fields, arguments and interface customization</a></h3>
|
||
<p>Similarly to <a href="https://spec.graphql.org/October2021#sec-Objects">GraphQL objects</a> Juniper allows to fully customize <a href="https://spec.graphql.org/October2021#sec-Interfaces">interface</a> fields and their arguments.</p>
|
||
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(deprecated)]
|
||
</span><span class="boring">extern crate juniper;
|
||
</span>use juniper::graphql_interface;
|
||
|
||
// Renames the interface in GraphQL schema.
|
||
#[graphql_interface(name = "MyCharacter")]
|
||
// Describes the interface in GraphQL schema.
|
||
#[graphql_interface(description = "My own character.")]
|
||
// Usual Rust docs are supported too as GraphQL interface description,
|
||
// but `description` attribute argument takes precedence over them, if specified.
|
||
/// This doc is absent in GraphQL schema.
|
||
trait Character {
|
||
// Renames the field in GraphQL schema.
|
||
#[graphql(name = "myId")]
|
||
// Deprecates the field in GraphQL schema.
|
||
// Usual Rust `#[deprecated]` attribute is supported too as field deprecation,
|
||
// but `deprecated` attribute argument takes precedence over it, if specified.
|
||
#[graphql(deprecated = "Do not use it.")]
|
||
// Describes the field in GraphQL schema.
|
||
#[graphql(description = "ID of my own character.")]
|
||
// Usual Rust docs are supported too as field description,
|
||
// but `description` attribute argument takes precedence over them, if specified.
|
||
/// This description is absent in GraphQL schema.
|
||
fn id(
|
||
&self,
|
||
// Renames the argument in GraphQL schema.
|
||
#[graphql(name = "myNum")]
|
||
// Describes the argument in GraphQL schema.
|
||
#[graphql(description = "ID number of my own character.")]
|
||
// Specifies the default value for the argument.
|
||
// The concrete value may be omitted, and the `Default::default` one
|
||
// will be used in such case.
|
||
#[graphql(default = 5)]
|
||
num: i32,
|
||
) -> &str;
|
||
}
|
||
<span class="boring">
|
||
</span><span class="boring">fn main() {}</span></code></pre></pre>
|
||
<p>Renaming policies for all <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interface</a> fields and arguments are supported as well:</p>
|
||
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(deprecated)]
|
||
</span><span class="boring">extern crate juniper;
|
||
</span>use juniper::graphql_interface;
|
||
|
||
#[graphql_interface(rename_all = "none")] // disables any renaming
|
||
trait Character {
|
||
// Now exposed as `my_id` and `my_num` in the schema
|
||
fn my_id(&self, my_num: i32) -> &str;
|
||
}
|
||
<span class="boring">
|
||
</span><span class="boring">fn main() {}</span></code></pre></pre>
|
||
<h3 id="custom-context"><a class="header" href="#custom-context">Custom context</a></h3>
|
||
<p>If a <a href="https://docs.rs/juniper/0.14.2/juniper/trait.Context.html"><code>Context</code></a> is required in a trait method to resolve a <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interface</a> field, specify it as an argument.</p>
|
||
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
|
||
</span><span class="boring">use std::collections::HashMap;
|
||
</span>use juniper::{graphql_interface, GraphQLObject};
|
||
|
||
struct Database {
|
||
humans: HashMap<String, Human>,
|
||
}
|
||
impl juniper::Context for Database {}
|
||
|
||
#[graphql_interface(for = Human)] // look, ma, context type is inferred! ＼(^o^)／
|
||
trait Character { // while still can be specified via `Context = ...` attribute argument
|
||
// If a field argument is named `context` or `ctx`, it's automatically assumed
|
||
// as a context argument.
|
||
fn id(&self, context: &Database) -> Option<&str>;
|
||
|
||
// Otherwise, you may mark it explicitly as a context argument.
|
||
fn name(&self, #[graphql(context)] db: &Database) -> Option<&str>;
|
||
}
|
||
|
||
#[derive(GraphQLObject)]
|
||
#[graphql(impl = CharacterValue, Context = Database)]
|
||
struct Human {
|
||
id: String,
|
||
name: String,
|
||
}
|
||
<span class="boring">
|
||
</span><span class="boring">fn main() {}</span></code></pre></pre>
|
||
<h3 id="using-executor-and-explicit-generic-scalar"><a class="header" href="#using-executor-and-explicit-generic-scalar">Using executor and explicit generic scalar</a></h3>
|
||
<p>If an <a href="https://docs.rs/juniper/latest/juniper/struct.Executor.html"><code>Executor</code></a> is required in a trait method to resolve a <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interface</a> field, specify it as an argument.</p>
|
||
<p>This requires to explicitly parametrize over <a href="https://docs.rs/juniper/latest/juniper/trait.ScalarValue.html"><code>ScalarValue</code></a>, as <a href="https://docs.rs/juniper/latest/juniper/struct.Executor.html"><code>Executor</code></a> does so.</p>
|
||
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
|
||
</span>use juniper::{graphql_interface, graphql_object, Executor, ScalarValue};
|
||
|
||
#[graphql_interface(for = Human, Scalar = S)] // notice specifying `ScalarValue` as existing type parameter
|
||
trait Character<S: ScalarValue> {
|
||
// If a field argument is named `executor`, it's automatically assumed
|
||
// as an executor argument.
|
||
fn id<'a>(&self, executor: &'a Executor<'_, '_, (), S>) -> &'a str;
|
||
|
||
// Otherwise, you may mark it explicitly as an executor argument.
|
||
fn name<'b>(
|
||
&'b self,
|
||
#[graphql(executor)] another: &Executor<'_, '_, (), S>,
|
||
) -> &'b str;
|
||
|
||
fn home_planet(&self) -> &str;
|
||
}
|
||
|
||
struct Human {
|
||
id: String,
|
||
name: String,
|
||
home_planet: String,
|
||
}
|
||
#[graphql_object(scalar = S: ScalarValue, impl = CharacterValue<S>)]
|
||
impl Human {
|
||
async fn id<'a, S>(&self, executor: &'a Executor<'_, '_, (), S>) -> &'a str
|
||
where
|
||
S: ScalarValue,
|
||
{
|
||
executor.look_ahead().field_name()
|
||
}
|
||
|
||
async fn name<'b, S>(&'b self, #[graphql(executor)] _: &Executor<'_, '_, (), S>) -> &'b str {
|
||
&self.name
|
||
}
|
||
|
||
fn home_planet<'c, S>(&'c self, #[graphql(executor)] _: &Executor<'_, '_, (), S>) -> &'c str {
|
||
// Executor may not be present on the trait method ^^^^^^^^^^^^^^^^^^^^^^^^
|
||
&self.home_planet
|
||
}
|
||
}
|
||
<span class="boring">
|
||
</span><span class="boring">fn main() {}</span></code></pre></pre>
|
||
<h2 id="scalarvalue-considerations"><a class="header" href="#scalarvalue-considerations"><code>ScalarValue</code> considerations</a></h2>
|
||
<p>By default, <code>#[graphql_interface]</code> macro generates code, which is generic over a <a href="https://docs.rs/juniper/latest/juniper/trait.ScalarValue.html"><code>ScalarValue</code></a> type. This may introduce a problem when at least one of <a href="https://spec.graphql.org/October2021#sec-Interfaces">GraphQL interface</a> implementers is restricted to a concrete <a href="https://docs.rs/juniper/latest/juniper/trait.ScalarValue.html"><code>ScalarValue</code></a> type in its implementation. To resolve such problem, a concrete <a href="https://docs.rs/juniper/latest/juniper/trait.ScalarValue.html"><code>ScalarValue</code></a> type should be specified.</p>
|
||
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">extern crate juniper;
|
||
</span>use juniper::{graphql_interface, DefaultScalarValue, GraphQLObject};
|
||
|
||
#[graphql_interface(for = [Human, Droid])]
|
||
#[graphql_interface(scalar = DefaultScalarValue)] // removing this line will fail compilation
|
||
trait Character {
|
||
fn id(&self) -> &str;
|
||
}
|
||
|
||
#[derive(GraphQLObject)]
|
||
#[graphql(impl = CharacterValue, Scalar = DefaultScalarValue)]
|
||
struct Human {
|
||
id: String,
|
||
home_planet: String,
|
||
}
|
||
|
||
#[derive(GraphQLObject)]
|
||
#[graphql(impl = CharacterValue, Scalar = DefaultScalarValue)]
|
||
struct Droid {
|
||
id: String,
|
||
primary_function: String,
|
||
}
|
||
<span class="boring">
|
||
</span><span class="boring">fn main() {}</span></code></pre></pre>
|
||
|
||
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