From 93b3b54cac111db5eb95675a4d87ed660631b9e9 Mon Sep 17 00:00:00 2001
From: djhi <1122076+djhi@users.noreply.github.com>
Date: Mon, 6 Jan 2020 12:44:07 +0100
Subject: [PATCH 1/2] Ensure resource data in redux store is initialized
 bebfore using it. Fixes #4196

---
 packages/ra-core/src/controller/useListController.ts  | 8 +++++---
 packages/ra-core/src/controller/useListParams.ts      | 5 ++++-
 packages/ra-core/src/controller/useRecordSelection.ts | 4 +++-
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/packages/ra-core/src/controller/useListController.ts b/packages/ra-core/src/controller/useListController.ts
index ab2f3a29c48..bf15d90f715 100644
--- a/packages/ra-core/src/controller/useListController.ts
+++ b/packages/ra-core/src/controller/useListController.ts
@@ -171,7 +171,7 @@ const useListController = (props: ListProps): ListControllerProps => {
         (state: ReduxState) =>
             state.admin.resources[resource]
                 ? state.admin.resources[resource].data
-                : null,
+                : {},
         shallowEqual
     );
 
@@ -209,7 +209,8 @@ const useListController = (props: ListProps): ListControllerProps => {
         displayedFilters: query.displayedFilters,
         filterValues: query.filterValues,
         hasCreate,
-        ids,
+        // ids might be null if the resource has not been initialized yet (custom routes for example)
+        ids: ids || [],
         loading,
         loaded,
         onSelect: selectionModifiers.select,
@@ -225,7 +226,8 @@ const useListController = (props: ListProps): ListControllerProps => {
         setPage: queryModifiers.setPage,
         setPerPage: queryModifiers.setPerPage,
         setSort: queryModifiers.setSort,
-        total,
+        // total might be null if the resource has not been initialized yet (custom routes for example)
+        total: total != undefined ? total : 0, // eslint-disable-line eqeqeq
         version,
     };
 };
diff --git a/packages/ra-core/src/controller/useListParams.ts b/packages/ra-core/src/controller/useListParams.ts
index 3086fa63103..b50a87f9d8d 100644
--- a/packages/ra-core/src/controller/useListParams.ts
+++ b/packages/ra-core/src/controller/useListParams.ts
@@ -114,7 +114,10 @@ const useListParams = ({
     const history = useHistory();
 
     const { params } = useSelector(
-        (reduxState: ReduxState) => reduxState.admin.resources[resource].list,
+        (reduxState: ReduxState) =>
+            reduxState.admin.resources[resource]
+                ? reduxState.admin.resources[resource].list
+                : {},
         shallowEqual
     );
 
diff --git a/packages/ra-core/src/controller/useRecordSelection.ts b/packages/ra-core/src/controller/useRecordSelection.ts
index f88cdf2b30d..1e4a7609857 100644
--- a/packages/ra-core/src/controller/useRecordSelection.ts
+++ b/packages/ra-core/src/controller/useRecordSelection.ts
@@ -14,7 +14,9 @@ const useSelectItems = (resource: string) => {
     const dispatch = useDispatch();
     const selectedIds = useSelector(
         (reduxState: ReduxState) =>
-            reduxState.admin.resources[resource].list.selectedIds,
+            reduxState.admin.resources[resource]
+                ? reduxState.admin.resources[resource].list.selectedIds
+                : [],
         shallowEqual
     );
     const selectionModifiers = {

From 58553db31cd6d7fa848e1a72f49c9790789e91d3 Mon Sep 17 00:00:00 2001
From: djhi <1122076+djhi@users.noreply.github.com>
Date: Mon, 6 Jan 2020 16:51:28 +0100
Subject: [PATCH 2/2] Review

---
 packages/ra-core/src/controller/useListController.ts  | 4 +++-
 packages/ra-core/src/controller/useListParams.ts      | 4 +++-
 packages/ra-core/src/controller/useRecordSelection.ts | 4 +++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/ra-core/src/controller/useListController.ts b/packages/ra-core/src/controller/useListController.ts
index bf15d90f715..d08377bd15f 100644
--- a/packages/ra-core/src/controller/useListController.ts
+++ b/packages/ra-core/src/controller/useListController.ts
@@ -41,6 +41,8 @@ const defaultSort = {
     order: SORT_ASC,
 };
 
+const defaultData = {};
+
 export interface ListControllerProps {
     basePath: string;
     currentSort: Sort;
@@ -171,7 +173,7 @@ const useListController = (props: ListProps): ListControllerProps => {
         (state: ReduxState) =>
             state.admin.resources[resource]
                 ? state.admin.resources[resource].data
-                : {},
+                : defaultData,
         shallowEqual
     );
 
diff --git a/packages/ra-core/src/controller/useListParams.ts b/packages/ra-core/src/controller/useListParams.ts
index b50a87f9d8d..36705352e55 100644
--- a/packages/ra-core/src/controller/useListParams.ts
+++ b/packages/ra-core/src/controller/useListParams.ts
@@ -52,6 +52,8 @@ const defaultSort = {
     order: SORT_ASC,
 };
 
+const defaultParams = {};
+
 /**
  * Get the list parameters (page, sort, filters) and modifiers.
  *
@@ -117,7 +119,7 @@ const useListParams = ({
         (reduxState: ReduxState) =>
             reduxState.admin.resources[resource]
                 ? reduxState.admin.resources[resource].list
-                : {},
+                : defaultParams,
         shallowEqual
     );
 
diff --git a/packages/ra-core/src/controller/useRecordSelection.ts b/packages/ra-core/src/controller/useRecordSelection.ts
index 1e4a7609857..106909a7578 100644
--- a/packages/ra-core/src/controller/useRecordSelection.ts
+++ b/packages/ra-core/src/controller/useRecordSelection.ts
@@ -3,6 +3,8 @@ import { useSelector, useDispatch, shallowEqual } from 'react-redux';
 import { setListSelectedIds, toggleListItem } from '../actions/listActions';
 import { Identifier, ReduxState } from '../types';
 
+const defaultRecords = [];
+
 /**
  * Get the list of selected items for a resource, and callbacks to change the selection
  *
@@ -16,7 +18,7 @@ const useSelectItems = (resource: string) => {
         (reduxState: ReduxState) =>
             reduxState.admin.resources[resource]
                 ? reduxState.admin.resources[resource].list.selectedIds
-                : [],
+                : defaultRecords,
         shallowEqual
     );
     const selectionModifiers = {