Merged submission module code

src/app/core/json-patch/selectors.ts

@@ -0,0 +1,34 @@
+// @TODO: Merge with keySelector function present in 'src/app/core/shared/selectors.ts'
+import { createSelector, MemoizedSelector, Selector } from '@ngrx/store';
+import { hasValue } from '../../shared/empty.util';
+import { coreSelector, CoreState } from '../core.reducers';
+import { JsonPatchOperationsEntry, JsonPatchOperationsResourceEntry } from './json-patch-operations.reducer';
+
+export function keySelector<T, V>(parentSelector: Selector<any, any>, subState: string, key: string): MemoizedSelector<T, V> {
+  return createSelector(parentSelector, (state: T) => {
+    if (hasValue(state[subState])) {
+      return state[subState][key];
+    } else {
+      return undefined;
+    }
+  });
+}
+
+export function subStateSelector<T, V>(parentSelector: Selector<any, any>, subState: string): MemoizedSelector<T, V> {
+  return createSelector(parentSelector, (state: T) => {
+    if (hasValue(state[subState])) {
+      return state[subState];
+    } else {
+      return undefined;
+    }
+  });
+}
+
+export function jsonPatchOperationsByResourceType(resourceType: string): MemoizedSelector<CoreState, JsonPatchOperationsResourceEntry> {
+  return keySelector<CoreState, JsonPatchOperationsResourceEntry>(coreSelector,'json/patch', resourceType);
+}
+
+export function jsonPatchOperationsByResourcId(resourceType: string, resourceId: string): MemoizedSelector<CoreState, JsonPatchOperationsEntry> {
+  const resourceTypeSelector  = jsonPatchOperationsByResourceType(resourceType);
+  return subStateSelector<CoreState, JsonPatchOperationsEntry>(resourceTypeSelector, resourceId);
+}