Moved all objects to a single data store: the cache.

src/app/shared/demo-cache.service.ts

@@ -0,0 +1,88 @@
+import { Inject, Injectable, isDevMode } from '@angular/core';
+
+@Injectable()
+export class DemoCacheService {
+  static KEY = 'DemoCacheService';
+
+  constructor( @Inject('LRU') public _cache: Map<string, any>) {
+
+  }
+
+  /**
+   * check if there is a value in our store
+   */
+  has(key: string | number): boolean {
+    let _key = this.normalizeKey(key);
+    return this._cache.has(_key);
+  }
+
+  /**
+   * store our state
+   */
+  set(key: string | number, value: any): void {
+    let _key = this.normalizeKey(key);
+    this._cache.set(_key, value);
+  }
+
+  /**
+   * get our cached value
+   */
+  get(key: string | number): any {
+    let _key = this.normalizeKey(key);
+    return this._cache.get(_key);
+  }
+
+  /**
+   * release memory refs
+   */
+  clear(): void {
+    this._cache.clear();
+  }
+
+  /**
+   * convert to json for the client
+   */
+  dehydrate(): any {
+    let json = {};
+    this._cache.forEach((value: any, key: string) => json[key] = value);
+    return json;
+  }
+
+  /**
+   * convert server json into out initial state
+   */
+  rehydrate(json: any): void {
+    Object.keys(json).forEach((key: string) => {
+      let _key = this.normalizeKey(key);
+      let value = json[_key];
+      this._cache.set(_key, value);
+    });
+  }
+
+  /**
+   * allow JSON.stringify to work
+   */
+  toJSON(): any {
+    return this.dehydrate();
+  }
+
+  /**
+   * convert numbers into strings
+   */
+  normalizeKey(key: string | number): string {
+    if (isDevMode() && this._isInvalidValue(key)) {
+      throw new Error('Please provide a valid key to save in the DemoCacheService');
+    }
+
+    return key + '';
+  }
+
+  _isInvalidValue(key): boolean {
+    return key === null ||
+      key === undefined ||
+      key === 0 ||
+      key === '' ||
+      typeof key === 'boolean' ||
+      Number.isNaN(<number>key);
+  }
+}