feat(core): add semantic composed thing

packages/core/src/semantic-consumed-thing.ts

@@ -0,0 +1,89 @@
+/********************************************************************************
+ * Copyright (c) 2023 Contributors to the Eclipse Foundation
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the W3C Software Notice and
+ * Document License (2015-05-13) which is available at
+ * https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR W3C-20150513
+ ********************************************************************************/
+
+import * as WoT from "wot-typescript-definitions";
+
+import ConsumedThing from "./consumed-thing";
+
+/**
+ * Represents a semantic composed thing (i.e. helper wrapper around ConsumedThing) to allow interactions
+ * with a thing based on semantic types.
+ * @experimental
+ */
+export default class SemanticConsumedThing extends ConsumedThing implements WoT.ConsumedThing {
+    /**
+     * Read a property based on semantic type
+     */
+    // Open Questions
+    // - define semantic input as string and/or array
+    // - allow AND / OR combinations? e.g., @type must have XYZ but should not have CBA
+    // - do we want to make the selection on output type as well ?
+    async readSemanticProperty(semanticType: string, options?: WoT.InteractionOptions): Promise<WoT.InteractionOutput> {
+        // try to find property by semantic look-up
+        const propertyName = this.getSemanticPropertyName(semanticType);
+        if (propertyName != null) {
+            // found property -> hand over to core functionality
+            return this.readProperty(propertyName, options);
+        }
+        // no match found
+        throw new Error(
+            `SemanticConsumedThing '${this.title}' did not find suitable semantic property for ${semanticType}`
+        );
+    }
+
+    private getSemanticPropertyName(semanticType: string): string | undefined {
+        // walk over available properties and find (the) right one
+        // e.g., .read( {"@type": "iot:BinarySwitchData"}
+        for (const propertyName in this.properties) {
+            const property = this.properties[propertyName];
+            if (property["@type"] != null) {
+                if (typeof property["@type"] === "string") {
+                    if (property["@type"] === semanticType) {
+                        return propertyName;
+                    }
+                } else if (Array.isArray(property["@type"])) {
+                    const types = property["@type"];
+                    if (types.includes(semanticType)) {
+                        return propertyName;
+                    }
+                }
+            }
+        }
+        return undefined;
+    }
+
+    // Open Questions
+    // - is a method necessary to check for availability ?
+    public isSemanticPropertyAvailable(semanticType: string): boolean {
+        return this.getSemanticPropertyName(semanticType) != null;
+    }
+
+    /**
+     * Write a property based on semantic type
+     */
+    // Open Questions
+    // - how to know the input value up-front ?
+    // - how to select desired property based on input type?
+    async writeSemanticProperty(
+        propertyName: string,
+        value: WoT.InteractionInput,
+        options?: WoT.InteractionOptions
+    ): Promise<void> {
+        throw new Error(`Not implemented`);
+    }
+
+    // ..., invokeAction, readAllProperties, readMultipleProperties, ...
+    // w.r.t. interaction that need input and/or provide output we might want to know the input/output type as well
+}