application/source/dom/customelement.mjs

@@ -26,7 +26,7 @@ import {
 } from "./constants.mjs";
 import {findDocumentTemplate, Template} from "./template.mjs";
 import {Updater} from "./updater.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {CustomElement, initMethodSymbol, assembleMethodSymbol, attributeObserverSymbol, registerCustomElement, assignUpdaterToElement, getSlottedElements}
 
 /**
@@ -195,6 +195,16 @@ class CustomElement extends HTMLElement {
         this[initMethodSymbol]();
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/custom-element");
+    }
+
+
     /**
      * This method determines which attributes are to be monitored by `attributeChangedCallback()`.
      *

application/source/dom/focusmanager.mjs

@@ -11,7 +11,7 @@ import {getGlobalObject} from "../types/global.mjs";
 import {isArray} from "../types/is.mjs";
 import {Stack} from "../types/stack.mjs";
 import {validateInstance, validateString} from "../types/validate.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {FocusManager}
 
 /**
@@ -57,6 +57,16 @@ const stackSymbol = Symbol('stack');
         this[stackSymbol] = new Stack();
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/focusmanager");
+    }
+
+
     /**
      * @property {HTMLDocument} document the document object into which the node is to be appended
      */

application/source/dom/resource.mjs

@@ -14,6 +14,7 @@ import {isString} from "../types/is.mjs";
 import {Observer} from "../types/observer.mjs";
 import {ProxyObserver} from "../types/proxyobserver.mjs";
 import {ATTRIBUTE_CLASS, ATTRIBUTE_ID, ATTRIBUTE_TITLE} from "./constants.mjs";
+import {instanceSymbol} from "../constants.mjs";
 
 export {Resource, KEY_DOCUMENT, KEY_QUERY, referenceSymbol}
 
@@ -191,6 +192,13 @@ class Resource extends BaseWithOptions {
         throw new Error("this method must be implemented by derived classes");
     }
     
+    /**
+     * @return {symbol}
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/resource");
+    }
+
 }
 
 

application/source/dom/resource/data.mjs

@@ -18,7 +18,7 @@ import {
     TAG_SCRIPT
 } from "../constants.mjs";
 import {KEY_DOCUMENT, KEY_QUERY, referenceSymbol, Resource} from "../resource.mjs";
-
+import {instanceSymbol} from '../../constants.mjs';
 export {Data}
 
 /**
@@ -70,6 +70,16 @@ class Data extends Resource {
         return this;
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/resource/data");
+    }
+
+
     /**
      * @return {string}
      */

application/source/dom/resource/link.mjs

@@ -15,7 +15,7 @@ import {
     TAG_LINK
 } from "../constants.mjs";
 import {KEY_DOCUMENT, referenceSymbol, Resource} from "../resource.mjs";
-
+import {instanceSymbol} from '../../constants.mjs';
 export {Link}
 
 /**
@@ -67,6 +67,16 @@ class Link extends Resource {
         })
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/resource/link");
+    }
+
+
     /**
      *
      * @return {Monster.DOM.Resource.Link}

application/source/dom/resource/link/stylesheet.mjs

@@ -7,7 +7,7 @@
 
 import {extend} from "../../../data/extend.mjs";
 import {Link} from "../link.mjs";
-
+import {instanceSymbol} from '../../../constants.mjs';
 export {Stylesheet}
 
 /**
@@ -31,5 +31,15 @@ class Stylesheet extends Link {
         })
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/resource/link/stylesheet")
+    }
+
+
 }
 

application/source/dom/resource/script.mjs

@@ -16,7 +16,7 @@ import {
     TAG_SCRIPT
 } from "../constants.mjs";
 import {KEY_DOCUMENT, referenceSymbol, Resource} from "../resource.mjs";
-
+import {instanceSymbol} from '../../constants.mjs';
 export {Script}
 
 /**
@@ -53,6 +53,15 @@ class Script extends Resource {
         })
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/resource/script");
+    }
+
     /**
      *
      * @return {Monster.DOM.Resource.Script}

application/source/dom/template.mjs

@@ -10,7 +10,7 @@ import {getGlobalFunction, getGlobalObject} from '../types/global.mjs';
 import {validateInstance, validateString} from "../types/validate.mjs";
 import {ATTRIBUTE_TEMPLATE_PREFIX} from "./constants.mjs";
 import {getDocumentTheme} from "./theme.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {Template}
 
 /**
@@ -37,6 +37,16 @@ class Template extends Base {
         this.template = template;
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/resource/template");
+    }
+
+
     /**
      *
      * @returns {HTMLTemplateElement}

application/source/dom/theme.mjs

@@ -9,7 +9,7 @@ import {Base} from '../types/base.mjs';
 import {getGlobalObject} from '../types/global.mjs';
 import {validateString} from "../types/validate.mjs";
 import {ATTRIBUTE_THEME_NAME, DEFAULT_THEME} from "./constants.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {Theme, getDocumentTheme}
 
 /**
@@ -35,6 +35,16 @@ class Theme extends Base {
         this.name = name;
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/dom/theme");
+    }
+
+
     /**
      *
      * @returns {string}

application/source/types/base.mjs

@@ -5,11 +5,30 @@
  * License text available at https://www.gnu.org/licenses/agpl-3.0.en.html
  */
 
+import {instanceSymbol} from "../constants.mjs";
+
 export {Base}
 
+
 /**
  * This is the base class from which all monster classes are derived.
  * 
+ * This class has besides a `toString` which returns the json representation of the object
+ * also a functionality to check if an object is an instance of a class.
+ * 
+ * Therefor the class has a static method ` [Symbol.hasInstance](that)` which returns true if the object 
+ * is an instance of the class. 
+ * F
+ * @see [https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/hasInstance](developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/hasInstance)
+ *
+ * Derived classes should implement a static getter `instanceSymbol` which returns a unique symbol.
+ * 
+ * ```javascript
+ * static get [instanceSymbol]() {
+ *    return Symbol.for("@schukai/monster/types/base");
+ * }
+ * ```
+ *
  * The class was formerly called Object.
  *
  * @license AGPLv3
@@ -27,5 +46,86 @@ class Base extends Object {
         return JSON.stringify(this);
     };
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/base");
+    }
+
+    /**
+     * This method is called by the `instanceof` operator.
+     * @param that
+     * @returns {boolean}
+     * @since 2.1.0
+     */
+    static [Symbol.hasInstance](that) {
+
+        if (that === undefined || that === null || (typeof that !== "object" && typeof that !== "function")) {
+            return false;
+        }
+
+        const thatClass = Object.getPrototypeOf(that)
+        if (thatClass === undefined || thatClass === null || (typeof thatClass !== "object" && typeof thatClass !== "function")) {
+            return false;
+        }
+
+        if (checkInstanceSymbol.apply(this, [thatClass]) === true) {
+            return true;
+        }
+
+
+        // this call the static method of the super class, if there is one
+        return super[Symbol.hasInstance](that);
+
+    }
+
+}
+
+/**
+ * this function checks if the class has a static getter `instanceSymbol` and if the value of this getter is equal to the
+ * 
+ * @private
+ * @param obj
+ * @returns {boolean|any|boolean}
+ * @since 2.1.0
+ */
+function checkInstanceSymbol(obj) {
+
+    if (this.hasOwnProperty(instanceSymbol) === false) {
+        return false;
+    }
+
+    const proto = obj?.constructor;
+    if (proto === undefined || proto === null || (typeof proto !== "object" && typeof proto !== "function")) {
+        return false;
+    }
+
+    if (proto.hasOwnProperty(instanceSymbol) !== true) {
+        return checkInstanceSymbol.apply(this, [obj.__proto__]);
+    }
+
+    const symbol = proto[instanceSymbol];
+    if (symbol === undefined) {
 
+        if (obj.__proto__) {
+            return checkInstanceSymbol(obj.__proto__);
+        } else {
+            return false;
         }
+
+    }
+
+    if (symbol === this[instanceSymbol]) {
+        return true;
+    }
+    
+    return checkInstanceSymbol.apply(this, [obj.__proto__]);
+
+
+}
+
+
+

application/source/types/dataurl.mjs

@@ -9,7 +9,7 @@ import {Base} from "./base.mjs";
 import {isString} from "./is.mjs";
 import {MediaType, parseMediaType} from "./mediatype.mjs";
 import {validateBoolean, validateInstance, validateString} from "./validate.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {DataUrl, parseDataURL}
 
 /**
@@ -52,6 +52,16 @@ class DataUrl extends Base {
 
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/data-url");
+    }
+
+
     get content() {
         return this[internal].base64 ? atob(this[internal].content) : this[internal].content;
     }

application/source/types/mediatype.mjs

@@ -8,7 +8,7 @@
 import {Base} from "./base.mjs";
 import {isString} from "./is.mjs";
 import {validateArray, validateString} from "./validate.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {MediaType, parseMediaType}
 
 /**
@@ -57,6 +57,16 @@ class MediaType extends Base {
 
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/media-type");
+    }
+
+
     /**
      * @return {String}
      */

application/source/types/node.mjs

@@ -9,7 +9,7 @@ import {Base} from './base.mjs';
 import {isPrimitive} from "./is.mjs";
 import {NodeList} from './nodelist.mjs';
 import {validateInstance} from './validate.mjs';
-
+import {instanceSymbol} from '../constants.mjs';
 export {Node}
 
 /**
@@ -52,6 +52,16 @@ class Node extends Base {
 
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/node");
+    }
+    
+
     /**
      * @property {*}
      */

application/source/types/nodelist.mjs

@@ -8,7 +8,7 @@
 import {isArray, isInstance} from "./is.mjs";
 import {Node} from "./node.mjs";
 import {validateInstance} from "./validate.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {NodeList}
 
 /**
@@ -44,6 +44,16 @@ class NodeList extends Set {
         }
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/node-list");
+    }
+    
+
     /**
      *
      * @param {Node} node

application/source/types/observer.mjs

@@ -9,7 +9,7 @@ import {Base} from './base.mjs';
 import {isObject} from './is.mjs';
 import {TokenList} from './tokenlist.mjs';
 import {UniqueQueue} from './uniquequeue.mjs';
-
+import {instanceSymbol} from '../constants.mjs';
 export {Observer}
 
 /**
@@ -64,6 +64,16 @@ class Observer extends Base {
         this.queue = new UniqueQueue();
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/observer");
+    }
+    
+    
     /**
      *
      * @param {string} tag

application/source/types/proxyobserver.mjs

@@ -11,7 +11,7 @@ import {Observer} from "./observer.mjs";
 import {ObserverList} from "./observerlist.mjs";
 import {validateObject} from "./validate.mjs";
 import {extend} from "../data/extend.mjs";
-
+import {instanceSymbol} from '../constants.mjs';
 export {ProxyObserver}
 
 /**
@@ -50,6 +50,16 @@ export {ProxyObserver}
         this.observers = new ObserverList;
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/proxy-observer");
+    }
+
+
     /**
      * get the real object
      *

application/source/types/queue.mjs

@@ -6,7 +6,7 @@
  */
 
 import {Base} from './base.mjs';
-
+import {instanceSymbol} from '../constants.mjs';
 export {Queue}
 
 /**
@@ -29,6 +29,16 @@ class Queue extends Base {
         this.data = [];
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/queue");
+    }
+
+
 
     /**
      * @return {boolean}

application/source/types/stack.mjs

@@ -6,7 +6,7 @@
  */
 
 import {Base} from './base.mjs';
-
+import {instanceSymbol} from '../constants.mjs';
 export {Stack}
 
 /**
@@ -27,6 +27,15 @@ class Stack extends Base {
         this.data = [];
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/stack");
+    }
+
 
     /**
      * @return {boolean}

application/source/types/version.mjs

@@ -6,9 +6,11 @@
  */
 
 import {Base} from './base.mjs';
+import {instanceSymbol} from '../constants.mjs';
 
 export {Version, getMonsterVersion}
 
+
 /**
  * The version object contains a semantic version number
  *
@@ -72,6 +74,16 @@ class Version extends Base {
 
     }
 
+    /**
+     * This method is called by the `instanceof` operator.
+     * @returns {symbol}
+     * @since 2.1.0
+     */
+    static get [instanceSymbol]() {
+        return Symbol.for("@schukai/monster/types/version");
+    }
+
+
     /**
      *
      * @returns {string}
@@ -137,7 +149,7 @@ function getMonsterVersion() {
     }
 
     /** don't touch, replaced by make with package.json version */
-    monsterVersion = new Version('2.0.15')
+    monsterVersion = new Version('2.0.16')
 
     return monsterVersion;
 

development/package.json

 {
   "name": "monster",
-  "version": "2.0.15",
+  "version": "2.0.16",
   "description": "monster",
   "repository": {
     "type": "git",