- add classes inside app/library for creting Tethys xml: Field.ts, Strategy.ts, XmlModel.ts

- added model DocumentXmlCache.ts
- npm updates
- changed all models inside app/Models to use corrected BaseModel.ts
- added extra extension class DatasetExtension.ts for app/dataset.ts for caching internal and external fields

app/Library/Field.ts

@@ -0,0 +1,69 @@
+export default class Field {
+    // private _multiplicity: number | string = 1;
+    private _hasMultipleValues: boolean = false;
+    private _valueModelClass: string | null = null;
+    private _linkModelClass: string | null = null;
+    // private _owningModelClass: string | null = null;
+    private _value: any;
+    private _name: string;
+
+    constructor(name: string) {
+        this._name = name;
+        this._value = null;
+    }
+
+    getValueModelClass(): any {
+        return this._valueModelClass;
+    }
+
+    setValueModelClass(classname: any): Field {
+        this._valueModelClass = classname;
+        return this;
+    }
+
+    getName(): string {
+        return this._name;
+    }
+
+    // setOwningModelClass(classname: string): Field {
+    //     this._owningModelClass = classname;
+    //     return this;
+    // }
+
+    public setValue(value: string | string[] | number | boolean): Field {
+        if (value === null || value === this._value) {
+            return this;
+        }
+
+        if (Array.isArray(value) && value.length === 0) {
+            value = [];
+        } else if (typeof value === 'boolean') {
+            value = value ? 1 : 0;
+        } else {
+            this._value = value;
+        }
+        return this;
+    }
+    public getValue() {
+        return this._value;
+    }
+
+    hasMultipleValues(): boolean {
+        return this._hasMultipleValues;
+    }
+
+    setMultiplicity(max: number | '*'): Field {
+        if (max !== '*') {
+            if (typeof max !== 'number' || max < 1) {
+                throw new Error('Only integer values > 1 or "*" allowed.');
+            }
+        }
+        // this._multiplicity = max;
+        this._hasMultipleValues = (typeof max == 'number' && max > 1) || max === '*';
+        return this;
+    }
+
+    getLinkModelClass(): string | null {
+        return this._linkModelClass;
+    }
+}