Update documentation with updated interface handling

Including:
- [BC] Use `#[InterfaceType]` to define interfaces
- Allow defining interfaces on classes (optionally abstract)
- Allow cascading implemented and extended interfaces

docs/todo.md

@@ -9,7 +9,7 @@ This library is still work in progress:
 - ~~Inject autowiring services~~
 - ~~Connection, edge, nodes (see https://relay.dev/graphql/connections.htm)~~
 - ~~GraphQL interfaces, inheritance~~
+- ~~Interfaces extending interfaces (see https://graphql.org/learn/schema/#interface-types)~~
 - Subscriptions
-- Interfaces extending interfaces (see https://graphql.org/learn/schema/#interface-types)
 - Union types (see https://graphql.org/learn/schema/#union-types)
 - Directives (see https://graphql.org/learn/schema/#directives)

docs/usage.md

@@ -105,13 +105,14 @@ final readonly class YourType
 
 #### Inheritance and Interfaces
 
-GraphQL supports inheritance using interfaces. To configure an interface, simply add `#[Type]` to a PHP interface:
+GraphQL supports inheritance using interfaces. To configure an interface, simply add `#[InterfaceType]` to a PHP interface or (abstract) class:
 
 ```php
 use Jerowork\GraphqlAttributeSchema\Attribute\Field;
 use Jerowork\GraphqlAttributeSchema\Attribute\Type;
 
-#[Type]
+// Define an InterfaceType on interface
+#[InterfaceType]
 interface UserType
 {
     // With PHP 8.4, you can define fields using property hooks
@@ -122,6 +123,19 @@ interface UserType
     #[Field]
     public function getName(): ?string;
 }
+
+// Or define an InterfaceType on (abstract) class
+#[InterfaceType]
+abstract readonly class AbstractUserType
+{
+    public function __construct(
+        #[Field]
+        public string $id,
+    ) {}
+
+    #[Field]
+    abstract public function getName(): ?string;
+}
 ```
 
 Each implementation inherits all fields from the interface, in addition to its own fields:
@@ -147,6 +161,46 @@ final readonly class AgentType implements UserType
 }
 ```
 
+Other than a single `#[Type]` implementing one interface `#[InterfaceType]` as in the example above, 
+*GraphQL Attribute Schema* also supports multiple interfaces:
+
+```php
+use Jerowork\GraphqlAttributeSchema\Attribute\Field;
+use Jerowork\GraphqlAttributeSchema\Attribute\InterfaceType;
+
+#[InterfaceType]
+interface FooType 
+{
+    #[Field]
+    public function getFoo() : string;
+}
+
+#[InterfaceType]
+interface BarType extends FooType 
+{
+    #[Field]
+    public function getBar() : string;
+}
+
+#[InterfaceType]
+abstract readonly class AbstractBazType implements FooType 
+{
+    public function __construct(
+        #[Field]
+        public string $id,
+    ) {}
+
+    #[Field]
+    abstract public function getBaz() : string;
+}
+
+#[Type]
+final readonly class QuxType extends AbstractBazType
+{
+    // Implement all required logic from interfaces/extends 
+}
+```
+
 #### Automatic schema creation
 
 *GraphQL Attribute Schema* automatically reads the `__construct` signature and detects input arguments,