55946: Refactored item-select to object-select to allow for easier implementation of collection-select

src/app/shared/object-select/object-select.service.ts

@@ -0,0 +1,119 @@
+import { Injectable } from '@angular/core';
+import { createSelector, MemoizedSelector, Store } from '@ngrx/store';
+import { ObjectSelectionsState, ObjectSelectionState } from './object-select.reducer';
+import {
+  ObjectSelectionDeselectAction,
+  ObjectSelectionInitialDeselectAction,
+  ObjectSelectionInitialSelectAction, ObjectSelectionResetAction,
+  ObjectSelectionSelectAction, ObjectSelectionSwitchAction
+} from './object-select.actions';
+import { Observable } from 'rxjs/Observable';
+import { hasValue } from '../empty.util';
+import { map } from 'rxjs/operators';
+import { AppState } from '../../app.reducer';
+
+const selectionStateSelector = (state: ObjectSelectionsState) => state.objectSelection;
+const objectSelectionsStateSelector = (state: AppState) => state.objectSelection;
+
+/**
+ * Service that takes care of selecting and deselecting objects
+ */
+@Injectable()
+export class ObjectSelectService {
+
+  constructor(
+    private store: Store<ObjectSelectionsState>,
+    private appStore: Store<AppState>
+  ) {
+  }
+
+  /**
+   * Request the current selection of a given object
+   * @param {string} id The UUID of the object
+   * @returns {Observable<boolean>} Emits the current selection state of the given object, if it's unavailable, return false
+   */
+  getSelected(id: string): Observable<boolean> {
+    return this.store.select(selectionByIdSelector(id)).pipe(
+      map((object: ObjectSelectionState) => {
+        if (object) {
+          return object.checked;
+        } else {
+          return false;
+        }
+      })
+    );
+  }
+
+  /**
+   * Request the current selection of a given object
+   * @param {string} id The UUID of the object
+   * @returns {Observable<boolean>} Emits the current selection state of the given object, if it's unavailable, return false
+   */
+  getAllSelected(): Observable<string[]> {
+    return this.appStore.select(objectSelectionsStateSelector).pipe(
+      map((state: ObjectSelectionsState) => Object.keys(state).filter((key) => state[key].checked))
+    );
+  }
+
+  /**
+   * Dispatches an initial select action to the store for a given object
+   * @param {string} id The UUID of the object to select
+   */
+  public initialSelect(id: string): void {
+    this.store.dispatch(new ObjectSelectionInitialSelectAction(id));
+  }
+
+  /**
+   * Dispatches an initial deselect action to the store for a given object
+   * @param {string} id The UUID of the object to deselect
+   */
+  public initialDeselect(id: string): void {
+    this.store.dispatch(new ObjectSelectionInitialDeselectAction(id));
+  }
+
+  /**
+   * Dispatches a select action to the store for a given object
+   * @param {string} id The UUID of the object to select
+   */
+  public select(id: string): void {
+    this.store.dispatch(new ObjectSelectionSelectAction(id));
+  }
+
+  /**
+   * Dispatches a deselect action to the store for a given object
+   * @param {string} id The UUID of the object to deselect
+   */
+  public deselect(id: string): void {
+    this.store.dispatch(new ObjectSelectionDeselectAction(id));
+  }
+
+  /**
+   * Dispatches a switch action to the store for a given object
+   * @param {string} id The UUID of the object to select
+   */
+  public switch(id: string): void {
+    this.store.dispatch(new ObjectSelectionSwitchAction(id));
+  }
+
+  /**
+   * Dispatches a reset action to the store for all objects
+   */
+  public reset(): void {
+    this.store.dispatch(new ObjectSelectionResetAction(null));
+  }
+
+}
+
+function selectionByIdSelector(id: string): MemoizedSelector<ObjectSelectionsState, ObjectSelectionState> {
+  return keySelector<ObjectSelectionState>(id);
+}
+
+export function keySelector<T>(key: string): MemoizedSelector<ObjectSelectionsState, T> {
+  return createSelector(selectionStateSelector, (state: ObjectSelectionState) => {
+    if (hasValue(state)) {
+      return state[key];
+    } else {
+      return undefined;
+    }
+  });
+}