fix(core): update

ts/smartstate.classes.statepart.ts

@@ -6,9 +6,9 @@ import { startWith, takeUntil, map } from 'rxjs/operators';
 import { StateAction, IActionDef } from './smartstate.classes.stateaction';
 
 export class StatePart<TStatePartName, TStatePayload> {
-  name: TStatePartName;
-  state = new Subject<TStatePayload>();
-  stateStore: TStatePayload;
+  public name: TStatePartName;
+  public state = new Subject<TStatePayload>();
+  public stateStore: TStatePayload;
 
   constructor(nameArg: TStatePartName) {
     this.name = nameArg;
@@ -17,7 +17,7 @@ export class StatePart<TStatePartName, TStatePayload> {
   /**
    * gets the state from the state store
    */
-  getState(): TStatePayload {
+  public getState(): TStatePayload {
     return this.stateStore;
   }
 
@@ -25,7 +25,7 @@ export class StatePart<TStatePartName, TStatePayload> {
    * sets the stateStore to the new state
    * @param newStateArg
    */
-  setState(newStateArg: TStatePayload) {
+  public setState(newStateArg: TStatePayload) {
     this.stateStore = newStateArg;
     this.notifyChange();
   }
@@ -33,21 +33,27 @@ export class StatePart<TStatePartName, TStatePayload> {
   /**
    * notifies of a change on the state
    */
-  notifyChange() {
+  public notifyChange() {
     this.state.next(this.stateStore);
   }
 
   /**
    * selects a state or a substate
    */
-  select<T = TStatePayload>(selectorFn?: (state: TStatePayload) => T): Observable<T> {
+  public select<T = TStatePayload>(selectorFn?: (state: TStatePayload) => T): Observable<T> {
     if (!selectorFn) {
       selectorFn = (state: TStatePayload) => <T>(<any>state);
     }
 
     const mapped = this.state.pipe(
       startWith(this.getState()),
-      map(selectorFn)
+      map((stateArg) => {
+        try {
+          return selectorFn(stateArg);
+        } catch (e) {
+          // Nothing here
+        }
+      })
     );
 
     return mapped;
@@ -56,17 +62,33 @@ export class StatePart<TStatePartName, TStatePayload> {
   /**
    * creates an action capable of modifying the state
    */
-  createAction<TActionPayload>(
+  public createAction<TActionPayload>(
     actionDef: IActionDef<TStatePayload, TActionPayload>
   ): StateAction<TStatePayload, TActionPayload> {
-    return new StateAction(actionDef);
+    return new StateAction(this, actionDef);
   }
 
   /**
    * dispatches an action on the statepart level
    */
-  async dispatchAction<T>(stateAction: StateAction<TStatePayload, T>, actionPayload: T) {
+  public async dispatchAction<T>(stateAction: StateAction<TStatePayload, T>, actionPayload: T) {
     const newState = await stateAction.actionDef(this, actionPayload);
     this.setState(newState);
   }
+
+  /**
+   * waits until a certain part of the state becomes available
+   * @param selectorFn
+   */
+  public async waitUntilPresent<T = TStatePayload>(selectorFn?: (state: TStatePayload) => T): Promise<T> {
+    const done = plugins.smartpromise.defer<T>();
+    const selectedObservable = this.select(selectorFn);
+    const subscription = selectedObservable.subscribe(value => {
+      if (value) {
+        subscription.unsubscribe();
+        done.resolve(value);
+      }
+    });
+    return await done.promise;
+  }
 }