[2.x] fix(core): refresh user count and list after user creation (#4687)

* fix(core): refresh user count and list after user creation

* fix(core): type user

* whoops

Author: DavideIadeluca

framework/core/js/src/admin/components/CreateUserModal.tsx

@@ -8,13 +8,15 @@ import type Mithril from 'mithril';
 import Switch from '../../common/components/Switch';
 import { generateRandomString } from '../../common/utils/string';
 import Form from '../../common/components/Form';
+import type User from '../../common/models/User';
 
 export interface ICreateUserModalAttrs extends IFormModalAttrs {
   username?: string;
   email?: string;
   password?: string;
   token?: string;
   provided?: string[];
+  onCreated?: (user: User) => void;
 }
 
 export type SignupBody = {
@@ -208,17 +210,17 @@ export default class CreateUserModal<CustomAttrs extends ICreateUserModalAttrs =
     this.loading = true;
 
     app.store
-      .createRecord('users', {})
+      .createRecord<User>('users', {})
       .save(this.submitData(), {
         errorHandler: this.onerror.bind(this),
       })
-      .then(() => {
+      .then((createdUser) => {
         if (this.bulkAdd()) {
           this.resetData();
         } else {
           this.hide();
         }
-
+        this.attrs.onCreated?.(createdUser);
         this.alertAttrs = null;
       })
       .finally(() => {

framework/core/js/src/admin/components/UserListPage.tsx

@@ -62,15 +62,13 @@ export default class UserListPage extends AdminPage {
    * data provided by `AdminPayload.php`, or `flarum/statistics`
    * if installed.
    */
-  readonly userCount: number = app.data.modelStatistics.users.total;
+  private userCount: number = app.data.modelStatistics.users.total;
 
   /**
    * Get total number of user pages.
    */
   private getTotalPageCount(): number {
-    if (this.userCount === -1) return 0;
-
-    return Math.ceil(this.userCount / this.numPerPage);
+    return Math.max(1, Math.ceil(Math.max(0, this.userCount) / this.numPerPage));
   }
 
   /**
@@ -207,7 +205,22 @@ export default class UserListPage extends AdminPage {
 
     items.add(
       'createUser',
-      <Button className="Button UserListPage-createUserBtn" icon="fas fa-user-plus" onclick={() => app.modal.show(CreateUserModal)}>
+      <Button
+        className="Button UserListPage-createUserBtn"
+        icon="fas fa-user-plus"
+        onclick={() =>
+          app.modal.show(CreateUserModal, {
+            onCreated: (user: User) => {
+              this.userCount++;
+              if (app.data?.modelStatistics?.users) {
+                app.data.modelStatistics.users.total = this.userCount;
+              }
+              this.isLoadingPage = true;
+              this.loadPage(this.pageNumber);
+            },
+          })
+        }
+      >
         {app.translator.trans('core.admin.users.create_user_button')}
       </Button>,
       100