feat: remove CoAP subprotocol

lib/src/binding_coap/coap_client.dart

@@ -435,22 +435,14 @@ final class CoapClient extends ProtocolClient
       accept: form.accept,
     );
 
-    final subprotocol = form.coapSubprotocol ?? operationType.subprotocol;
-
     final coapClient = coap.CoapClient(
       form.resolvedHref,
       config: _InternalCoapConfig(_coapConfig ?? const CoapConfig()),
     );
 
-    if (subprotocol == CoapSubprotocol.observe) {
-      final observeClientRelation = await coapClient.observe(request);
-      observeClientRelation.listen(handleResponse);
-      return CoapSubscription(coapClient, observeClientRelation, complete);
-    }
-
-    final response = await coapClient.send(request);
-    handleResponse(response);
-    return CoapSubscription(coapClient, null, complete);
+    final observeClientRelation = await coapClient.observe(request);
+    observeClientRelation.listen(handleResponse);
+    return CoapSubscription(coapClient, observeClientRelation, complete);
   }
 
   @override

lib/src/binding_coap/coap_client_factory.dart

@@ -8,7 +8,6 @@ import "../../core.dart";
 
 import "coap_client.dart";
 import "coap_config.dart";
-import "coap_definitions.dart";
 
 /// A [ProtocolClientFactory] that produces CoAP clients.
 final class CoapClientFactory implements ProtocolClientFactory {
@@ -56,11 +55,6 @@ final class CoapClientFactory implements ProtocolClientFactory {
       OperationType.unsubscribeevent,
     ];
 
-    if (observeOperations.contains(operationType)) {
-      return CoapSubprotocol.tryParse(subprotocol ?? "") ==
-          CoapSubprotocol.observe;
-    }
-
-    return subprotocol == null;
+    return observeOperations.contains(operationType);
   }
 }

lib/src/binding_coap/coap_definitions.dart

@@ -50,20 +50,3 @@ enum CoapRequestMethod {
   static CoapRequestMethod? fromString(String stringValue) =>
       _registry[stringValue];
 }
-
-/// Enumeration of available CoAP subprotocols.
-enum CoapSubprotocol {
-  /// Subprotocol for observing CoAP resources.
-  observe,
-  ;
-
-  /// Tries to match the given [subprotocol] string to one of the known
-  /// [CoapSubprotocol.values].
-  static CoapSubprotocol? tryParse(String subprotocol) {
-    if (subprotocol == "cov:observe") {
-      return CoapSubprotocol.observe;
-    }
-
-    return null;
-  }
-}

lib/src/binding_coap/coap_extensions.dart

@@ -36,15 +36,6 @@ extension CoapFormExtension on AugmentedForm {
   bool get usesAutoScheme =>
       securityDefinitions.whereType<AutoSecurityScheme>().isNotEmpty;
 
-  /// Get the [CoapSubprotocol] for this [AugmentedForm], if one is set.
-  CoapSubprotocol? get coapSubprotocol {
-    if (subprotocol == coapPrefixMapping.expandCurieString("observe")) {
-      return CoapSubprotocol.observe;
-    }
-
-    return null;
-  }
-
   /// The Content-Format for CoAP request and response payloads.
   CoapMediaType get contentFormat {
     final formDefinition = _obtainVocabularyTerm<int>("contentFormat");
@@ -160,22 +151,6 @@ extension OperationTypeExtension on OperationType {
         return CoapRequestMethod.get;
     }
   }
-
-  /// Determines the [CoapSubprotocol] (if any) for this [OperationType].
-  ///
-  /// The only supported subprotocol at the moment is `observe`.
-  CoapSubprotocol? get subprotocol {
-    if ([
-      OperationType.subscribeevent,
-      OperationType.unsubscribeevent,
-      OperationType.observeproperty,
-      OperationType.unobserveproperty,
-    ].contains(this)) {
-      return CoapSubprotocol.observe;
-    }
-
-    return null;
-  }
 }
 
 /// Extension for easily extracting the [content] from a [CoapResponse].