caching for listAll methods

src-ui/src/app/services/rest/abstract-paperless-service.ts

@@ -1,5 +1,6 @@
 import { HttpClient, HttpParams } from '@angular/common/http'
-import { Observable } from 'rxjs'
+import { Observable, of, Subject } from 'rxjs'
+import { map, publishReplay, refCount } from 'rxjs/operators'
 import { ObjectWithId } from 'src/app/data/object-with-id'
 import { Results } from 'src/app/data/results'
 import { environment } from 'src/environments/environment'
@@ -51,8 +52,28 @@ export abstract class AbstractPaperlessService<T extends ObjectWithId> {
     return this.http.get<Results<T>>(this.getResourceUrl(), {params: httpParams})
   }
 
+  private _listAll: Observable<Results<T>>
+
   listAll(ordering?: string, extraParams?): Observable<Results<T>> {
-    return this.list(1, 100000, ordering, extraParams)
+    if (!this._listAll) {
+      this._listAll = this.list(1, 100000, ordering, extraParams).pipe(
+        publishReplay(1),
+        refCount()
+      )
+    }
+    return this._listAll
+  }
+
+  getCached(id: number): Observable<T> {
+    return this.listAll().pipe(
+      map(list => list.results.find(o => o.id == id))
+    )
+  }
+
+  getCachedMany(ids: number[]): Observable<T[]> {
+    return this.listAll().pipe(
+      map(list => ids.map(id => list.results.find(o => o.id == id)))
+    )
   }
 
   get(id: number): Observable<T> {
@@ -60,14 +81,17 @@ export abstract class AbstractPaperlessService<T extends ObjectWithId> {
   }
 
   create(o: T): Observable<T> {
+    this._listAll = null
     return this.http.post<T>(this.getResourceUrl(), o)
   }
 
   delete(o: T): Observable<any> {
+    this._listAll = null
     return this.http.delete(this.getResourceUrl(o.id))
   }
 
   update(o: T): Observable<T> {
+    this._listAll = null
     return this.http.put<T>(this.getResourceUrl(o.id), o)
   }
 }