closes #14 offer different strategies for model constraint violations

projects/emfular/src/lib/referencing/referencable/container/link/re-link-container.ts

@@ -2,18 +2,19 @@ import {Referencable} from "../../referenceable";
 import { ReContainer } from "../re-container";
 import {SerializationContext} from "../../../../serialization/serialization-context";
 import {Ref} from "../../../ref/ref";
+import { DeletionMode } from "../../../../utils/deletion-mode";
 
 export interface ReLinkContainer<
     T extends Referencable<any>,
     P extends Referencable<any>
 > extends ReContainer<T,P> {
 
-    /*protected constructor(parent: P, referenceName: string, inverseName?: string) {
-        super(parent, referenceName, inverseName);
+    /*protected constructor(parent: P, referenceName: string, isRequired: boolean, inverseName?: string) {
+        super(parent, referenceName, isRequired, inverseName);
         this._parent.$otherReferences.push(this)
     }*/
 
-    removeFromInverse(item: T): boolean;
+    removeFromInverse(item: T, mode?: DeletionMode): boolean;
 
     toJson(ctx: SerializationContext): Ref[] | Ref | undefined
 }

projects/emfular/src/lib/referencing/referencable/container/link/re-link-list-container.ts

@@ -5,6 +5,7 @@ import {ReLinkContainer} from "./re-link-container";
 import {ListUpdater} from "../../../../utils/list-updater";
 import {ReListContainer} from "../re-list-container";
 import {ReferenceMeta} from "../../../../binding/model-definition";
+import {DeletionMode} from "../../../../utils/deletion-mode";
 
 export class ReLinkListContainer<
     T extends Referencable<any>,
@@ -33,24 +34,24 @@ implements ReLinkContainer<T, P> {
         return this._instance.map(i => ctx.get(i))
     }
 
-    override remove(item: T): boolean {
+    override remove(item: T, mode: DeletionMode = DeletionMode.RELAXED): boolean {
         const res =  ListUpdater.removeFromList(item, this._instance)
         if (res) {
             if(this.inverseName !== undefined) {
-                item.removeFromReferencableContainer(this.inverseName, this._parent)
+                item.removeFromReferencableContainer(this.inverseName, this._parent, mode)
             }
         }
         return res; //todo behaviour of flag different to add??
     }
 
-    override delete() {
-        ListUpdater.destructAllFromChangingList(this._instance)
+    override delete(mode: DeletionMode = DeletionMode.RELAXED) {
+        ListUpdater.destructAllFromChangingList(this._instance, mode)
     }
 
-    removeFromInverse(item: T): boolean {
+    removeFromInverse(item: T, mode: DeletionMode = DeletionMode.RELAXED): boolean {
         if(this.inverseName !== undefined) {
             for (const child of [...this._instance]) {
-                child.removeFromReferencableContainer(this.inverseName, item)
+                child.removeFromReferencableContainer(this.inverseName, item, mode)
             }
             return true; // todo - refine?
         }

projects/emfular/src/lib/referencing/referencable/container/link/re-link-single-container.spec.ts

@@ -4,6 +4,6 @@ import {ReferencableTester, refTesterRef} from "../../../test/referencable-teste
 describe('ReLinkSingleContainer', () => {
   it('should create an instance', () => {
     let tester = new ReferencableTester()
-    expect(new ReLinkSingleContainer(tester, 'refName',  refTesterRef.references.test)).toBeTruthy();
+    expect(new ReLinkSingleContainer(tester, 'refName', refTesterRef.references.test)).toBeTruthy();
   });
 });

projects/emfular/src/lib/referencing/referencable/container/link/re-link-single-container.ts

@@ -4,6 +4,7 @@ import {SerializationContext} from "../../../../serialization/serialization-cont
 import {ReLinkContainer} from "./re-link-container";
 import {ReSingleContainer} from "../re-single-container";
 import {ReferenceMeta} from "../../../../binding/model-definition";
+import { DeletionMode } from "../../../../utils/deletion-mode";
 
 export class ReLinkSingleContainer<
     T extends Referencable<any>,
@@ -18,7 +19,7 @@ implements ReLinkContainer<T, P> {
 
     protected set(instance: T): void {
         if(this.inverseName !== undefined) {
-            this._instance?.removeFromReferencableContainer(this.inverseName, this._parent)
+            this._instance?.removeFromReferencableContainer(this.inverseName, this._parent, DeletionMode.RELAXED)
             this._instance = instance;
             instance.addToReferencableContainer(this.inverseName, this._parent)
         } else {
@@ -35,10 +36,10 @@ implements ReLinkContainer<T, P> {
         }
     }
 
-    remove(item: T): boolean {
+    remove(item: T, mode: DeletionMode = DeletionMode.RELAXED): boolean {
         if(this._instance == item) {
             if (this.inverseName != undefined) {
-                item.removeFromReferencableContainer(this.inverseName, this._parent)
+                item.removeFromReferencableContainer(this.inverseName, this._parent, mode)
             }
             this._instance = undefined;
             return true;
@@ -47,13 +48,13 @@ implements ReLinkContainer<T, P> {
         }
     }
 
-    override delete() {
-        this._instance?.destruct()
+    override delete(mode: DeletionMode = DeletionMode.RELAXED) {
+        this._instance?.destruct(mode)
     }
 
-    removeFromInverse(item: T): boolean {
+    removeFromInverse(item: T, mode: DeletionMode = DeletionMode.RELAXED): boolean {
         if(this.inverseName !== undefined) {
-            this._instance?.removeFromReferencableContainer(this.inverseName, item)
+            this._instance?.removeFromReferencableContainer(this.inverseName, item, mode)
             return true; // todo refine?
         }
         return false;

projects/emfular/src/lib/referencing/referencable/container/re-container.ts

@@ -2,6 +2,7 @@ import {Referencable} from "../referenceable";
 import {SerializationContext} from "../../../serialization/serialization-context";
 import {ReferenceMeta} from "../../../binding/model-definition";
 import {ModelRegistry} from "../../../binding/model-registry";
+import {DeletionMode} from "../../../utils/deletion-mode";
 
 export abstract class ReContainer<
     T extends Referencable<any>,
@@ -11,11 +12,13 @@ export abstract class ReContainer<
     readonly meta: ReferenceMeta;
     readonly referenceName: string;
     readonly inverseName?: string;
+    readonly isRequired: boolean;
 
     protected constructor(parent: P, referenceName: string, refMeta: ReferenceMeta) {
         this._parent = parent;
         this.meta = refMeta;
         this.referenceName = referenceName;
+        this.isRequired = this.meta.min != undefined && this.meta.min > 0;
         this.inverseName = refMeta.opposite;
     }
 
@@ -43,10 +46,10 @@ export abstract class ReContainer<
         return this.isAcceptableItem( new srcConstr()) //todo
     }
 
-    abstract remove(item: T): boolean;
+    abstract remove(item: T, mode?: DeletionMode): boolean;
 
     //called to destruct all elements in the container (e.g. when destroying a parent
-    abstract delete(): void
+    abstract delete(mode?: DeletionMode): void
 
     abstract toJson(ctx: SerializationContext): any
 }

projects/emfular/src/lib/referencing/referencable/container/re-list-container.ts

@@ -5,6 +5,7 @@ import {ModelList} from "./hide/model-list";
 import {createListProxy} from "./hide/list-proxy";
 import {ReListInterface} from "./re-list-interface";
 import {ReferenceMeta} from "../../../binding/model-definition";
+import {DeletionMode} from "../../../utils/deletion-mode";
 
 
 export abstract class ReListContainer<
@@ -32,8 +33,8 @@ implements ReListInterface<T, P>{
         return this._proxy;
     }
 
-    override delete() {
-        ListUpdater.destructAllFromChangingList(this._instance)
+    override delete(mode: DeletionMode = DeletionMode.RELAXED) {
+        ListUpdater.destructAllFromChangingList(this._instance, mode)
     }
 
     move(from: number, to: number) {

projects/emfular/src/lib/referencing/referencable/container/re-single-container.ts

@@ -11,7 +11,7 @@ implements ReSingleInterface<T, P>{
 
     protected _instance?: T ;
 
-    protected constructor(parent: P, referenceName: string, refMeta: ReferenceMeta ) {
+    protected constructor(parent: P, referenceName: string, refMeta: ReferenceMeta) {
         super(parent, referenceName, refMeta);
     }
 

projects/emfular/src/lib/referencing/referencable/container/shallow/re-derived-list-container.ts

@@ -22,7 +22,7 @@ export class ReDerivedListContainer<
         parent: P,
         computeOrSymbol: ((owner: P) => T[]) | symbol,
         referenceName: string,
-        refMeta: ReferenceMeta,
+        refMeta: ReferenceMeta
     ) {
         super(parent, referenceName, refMeta);
         this.resolver = new ReDerivationResolver(computeOrSymbol);

projects/emfular/src/lib/referencing/referencable/container/shallow/re-tree-parent-container.ts

@@ -4,6 +4,7 @@ import {ReContainer} from "../re-container";
 import {ReSingleInterface} from "../re-single-interface";
 import {ReShallowInterface} from "./re-shallow-interface";
 import {ReferenceMeta} from "../../../../binding/model-definition";
+import { DeletionMode } from "../../../../utils/deletion-mode";
 
 export class ReTreeParentContainer<T extends Referencable<any>>
     extends ReContainer<T["ParentType"],T>
@@ -23,13 +24,13 @@ implements ReSingleInterface<T["ParentType"], T>,
         let me: T = this._parent
         const currentParentCont = this._parent.parent
         if(currentParentCont != undefined) {
-            currentParentCont.remove(this._parent as T["ParentType"])
+            currentParentCont.remove(this._parent as T["ParentType"], DeletionMode.RELAXED)
         }
         return item.addToReferencableContainer(this.inverseName, me)
     }
 
-    remove(item: T["ParentType"]): boolean {
-        return item.removeFromReferencableContainer(this.inverseName, this._parent)
+    remove(item: T["ParentType"], mode: DeletionMode = DeletionMode.RELAXED): boolean {
+        return item.removeFromReferencableContainer(this.inverseName, this._parent, mode)
     }
 
     delete(): void {}

projects/emfular/src/lib/referencing/referencable/container/tree/re-tree-list-container.ts

@@ -5,6 +5,7 @@ import {JsonOf} from "../../../../serialization/json-deserializable";
 import {SerializationContext} from "../../../../serialization/serialization-context";
 import {ReTreeChildrenContainer} from "./re-tree-children-container";
 import {ListUpdater} from "../../../../utils/list-updater";
+import { DeletionMode } from "../../../../utils/deletion-mode";
 import {ReListContainer} from "../re-list-container";
 import {ReferenceMeta} from "../../../../binding/model-definition";
 
@@ -54,8 +55,8 @@ implements ReTreeChildrenContainer<T> {
         return false;
     }
 
-    override delete() {
-        ListUpdater.destructAllFromChangingList(this._instance)
+    override delete(mode: DeletionMode = DeletionMode.RELAXED) {
+        ListUpdater.destructAllFromChangingList(this._instance, mode)
     }
 
     //creates one child level plus calls next createChildren

projects/emfular/src/lib/referencing/referencable/container/tree/re-tree-single-container.ts

@@ -6,6 +6,7 @@ import {SerializationContext} from "../../../../serialization/serialization-cont
 import {ReTreeChildrenContainer} from "./re-tree-children-container";
 import {ReSingleContainer} from "../re-single-container";
 import {ReferenceMeta} from "../../../../binding/model-definition";
+import { DeletionMode } from "../../../../utils/deletion-mode";
 
 export class ReTreeSingleContainer<T extends Referencable<any>>
     extends ReSingleContainer<T, T["ParentType"]>
@@ -46,8 +47,12 @@ implements ReTreeChildrenContainer<T> {
         return false;
     }
 
-    delete() {
-        this._instance?.destruct()
+    delete(mode: DeletionMode = DeletionMode.RELAXED) {
+        if (mode === DeletionMode.CASCADE) {
+            this._instance?.destruct(mode)
+        } else if (mode === DeletionMode.RELAXED) {
+            this._instance?.parent?.remove(this._instance, mode)
+        }
     }
 
     fromJson(formerPrefix: string, context: Deserializer, json: any) {

projects/emfular/src/lib/referencing/referencable/referenceable.ts

@@ -11,6 +11,7 @@ import {ReTreeChildrenContainer} from "./container/tree/re-tree-children-contain
 import {ReLinkContainer} from "./container/link/re-link-container";
 import {ModelRegistry} from "../../binding/model-registry";
 import {ClassMeta, ModelDefinition, ReferenceMeta} from "../../binding/model-definition";
+import { DeletionMode } from "../../utils/deletion-mode";
 
 /** base class for CORE models.
  *
@@ -74,13 +75,13 @@ export abstract class Referencable<
     }
   }
 
-  destruct() {
-    this.$parent?.remove(this)
+  destruct(mode: DeletionMode = DeletionMode.RELAXED) {
+    this.$parent?.remove(this, mode)
     this.$otherReferences.forEach(refContainer => {
-      refContainer.removeFromInverse(this)
+      refContainer.removeFromInverse(this, mode)
     })
     this.$treeChildren.forEach(child => {
-      child.delete()
+      child.delete(mode)
     })
   }
 
@@ -111,13 +112,20 @@ export abstract class Referencable<
     return container as ReContainer<T, Parent>;
   }
 
-
   public addToReferencableContainer<T extends Referencable<any>>(name: string, item: T): boolean {
     return this.getContainer<T>(name).add(item)
   }
 
-  public removeFromReferencableContainer<T extends Referencable<any>>(name: string, item: T): boolean {
-    return this.getContainer<T>(name).remove(item)
+  public removeFromReferencableContainer<T extends Referencable<any>>(name: string, item: T, mode: DeletionMode = DeletionMode.RELAXED): boolean {
+    let container = this.getContainer<T>(name)
+    let result = container.remove(item, mode)
+    if (result && mode == DeletionMode.CASCADE && container.isRequired) {
+        const instance = container.get()
+        if (instance == undefined || (Array.isArray(instance) && instance.length == 0)) {
+          container._parent.destruct(mode)
+        }
+      }
+    return result
   }
 
   toJson(ctxOPt?: SerializationContext): JsonOf<this> {