Improve Agents preview page load when there are no agents

CHANGELOG.md

@@ -8,6 +8,10 @@ All notable changes to the Wazuh app project will be documented in this file.
 
 - Support for Wazuh 4.7.2
 
+### Fixed
+
+- Fixed Agents preview page load when there are no registered agents [#6185](https://github.com/wazuh/wazuh-dashboard-plugins/pull/6185)
+
 ## Wazuh v4.7.1 - OpenSearch Dashboards 2.8.0 - Revision 01
 
 ### Added

plugins/main/public/controllers/agent/components/agents-preview.js

@@ -23,6 +23,7 @@ import {
   EuiToolTip,
   EuiCard,
   EuiLink,
+  EuiProgress,
 } from '@elastic/eui';
 import { AgentsTable } from './agents-table';
 import { WzRequest } from '../../../react-services/wz-request';
@@ -219,6 +220,19 @@ export const AgentsPreview = compose(
     render() {
       const evolutionIsReady = this.props.resultState !== 'loading';
 
+      //This condition is because the angular template and the controller have a small delay to show the register agent component when there are no agents
+      //This condition must be removed when the controller is removed
+      if (
+        !this.state.agentStatusSummary.total ||
+        this.state.agentStatusSummary.total === '-'
+      ) {
+        return (
+          <div className='md-padding md-padding-top-16'>
+            <EuiProgress size='xs' color='primary' />
+          </div>
+        );
+      }
+
       return (
         <EuiPage className='flex-column'>
           <EuiFlexItem>

plugins/main/public/templates/agents-prev/agents-prev.html

@@ -59,7 +59,7 @@
     layout="column"
     layout-align="start space-around"
   >
-    <div class="registerAgent" ng-if="ctrl.addingNewAgent">
+    <div class="registerAgent" ng-show="ctrl.addingNewAgent">
       <react-component
         name="RegisterAgent"
         props="ctrl.registerAgentsProps"