progress july 11 - store/selection to object list

src/app/shared/object-list/selectable-list/selectable-list.service.ts

@@ -0,0 +1,94 @@
+import { Injectable } from '@angular/core';
+import { MemoizedSelector, select, Store } from '@ngrx/store';
+import { Observable } from 'rxjs';
+import { distinctUntilChanged, filter, map, startWith, tap } from 'rxjs/operators';
+import { SelectableListsState, SelectableListState } from './selectable-list.reducer';
+import { AppState, keySelector } from '../../../app.reducer';
+import { ListableObject } from '../../object-collection/shared/listable-object.model';
+import {
+  SelectableListDeselectAction, SelectableListDeselectAllAction,
+  SelectableListDeselectSingleAction, SelectableListSelectAction,
+  SelectableListSelectSingleAction
+} from './selectable-list.actions';
+import { hasNoValue, hasValue, isNotEmpty } from '../../empty.util';
+
+const selectableListsStateSelector = (state) => state.selectableLists;
+
+const menuByIDSelector = (id: string): MemoizedSelector<AppState, SelectableListState> => {
+  return keySelector<SelectableListState>(id, selectableListsStateSelector);
+};
+
+@Injectable()
+export class SelectableListService {
+
+  constructor(private store: Store<SelectableListsState>) {
+  }
+
+  /**
+   * Retrieve a selectable list's state by its ID
+   * @param {string} id ID of the requested Selectable list
+   * @returns {Observable<SelectableListState>} Observable that emits the current state of the requested selectable list
+   */
+  getSelectableList(id: string): Observable<SelectableListState> {
+    return this.store.pipe(select(menuByIDSelector(id)));
+  }
+
+  /**
+   * Select an object in a specific list in the store
+   * @param {string} id The id of the list on which the object should be selected
+   * @param {ListableObject} object The object to select
+   */
+  selectSingle(id: string, object: ListableObject, multipleSelectionsAllowed?) {
+    this.store.dispatch(new SelectableListSelectSingleAction(id, object, multipleSelectionsAllowed));
+  }
+
+  /**
+   * Select multiple objects in a specific list in the store
+   * @param {string} id The id of the list on which the objects should be selected
+   * @param {ListableObject[]} objects The objects to select
+   */
+  select(id: string, objects: ListableObject[]) {
+    this.store.dispatch(new SelectableListSelectAction(id, objects));
+  }
+
+  /**
+   * Deselect an object in a specific list in the store
+   * @param {string} id The id of the list on which the object should be deselected
+   * @param {ListableObject} object The object to deselect
+   */
+  deselectSingle(id: string, object: ListableObject) {
+    this.store.dispatch(new SelectableListDeselectSingleAction(id, object));
+  }
+
+  /**
+   * Deselect multiple objects in a specific list in the store
+   * @param {string} id The id of the list on which the objects should be deselected
+   * @param {ListableObject[]} objects The objects to deselect
+   */
+  deselect(id: string, objects: ListableObject[]) {
+    this.store.dispatch(new SelectableListDeselectAction(id, objects));
+  }
+
+  /**
+   * Deselect all objects in a specific list in the store
+   * @param {string} id The id of the list on which the objects should be deselected
+   */
+  deselectAll(id: string) {
+    this.store.dispatch(new SelectableListDeselectAllAction(id));
+  }
+
+  /**
+   * Check if a given object is selected in a specific list
+   * @param {string} id The ID of the selectable list the object should be selected in
+   * @param {ListableObject} object The object to check for if it's selected
+   * @returns {Observable<boolean>} Emits true if the given object is selected, emits false when it's deselected
+   */
+  isObjectSelected(id: string, object: ListableObject): Observable<boolean> {
+    return this.getSelectableList(id).pipe(
+      filter((state: SelectableListState) => hasValue(state)),
+      map((state: SelectableListState) => isNotEmpty(state.selection) && hasValue(state.selection.find((selected) => selected === object))),
+      startWith(false),
+      distinctUntilChanged()
+    );
+  }
+}