Create an Angular Front-End Application with a Document Viewer

• Mar 20, 2023
• 5 minutes to read

This document describes how to create a Reporting application with the Angular client part.

Note

You can use the DevExpress Angular SPA template to create an Angular Reporting application. For more information, refer to the following help topic: Use Visual Studio Templates to Create an Angular Application with a Document Viewer.

The project consists of the server and client parts.

Server (Back-End) Application

Review the following topics to create a back-end application:

• Document Viewer’s Server-Side Configuration (ASP.NET MVC)
• Document Viewer Server-Side Application (ASP.NET Core)

Client (Front-End) Application

Perform the following steps to create and configure the client part:

1. Make sure you have the current Node.js version with npm installed on your machine.

   node -v
   npm -v
   

2. Open the console window and install the Angular CLI globally.

   npm install -g @angular/cli
   

   When prompted for options, select default settings (press Enter).

3. Create a new folder to store client files. Navigate to the created folder and run the command to create a new project:

   ng new angular-example --strict=false
   

   Refer to the Angular documentation for information on the Angular application structure.

4. Change your current directory to the project root folder and install the following packages:

   • devextreme
   • @devexpress/analytics-core
   • devexpress-reporting-angular

   cd angular-report-designer
   npm install devextreme@23.1-stable @devexpress/analytics-core@23.1-stable devexpress-reporting-angular@23.1-stable
   

   Note

   Front-end and back-end applications should use the same version of DevExpress controls.

5. Replace the content of the angular-example\src\app\app.module.ts file with the following code:

   app.module.ts

   import { BrowserModule } from '@angular/platform-browser';
   import { NgModule } from '@angular/core';
   
   import { AppComponent } from './app.component';
   import { DxReportViewerModule } from 'devexpress-reporting-angular';
   
   @NgModule({
   declarations: [
       AppComponent
   ],
   imports: [
       BrowserModule,
       DxReportViewerModule
   ],
   providers: [],
   bootstrap: [AppComponent]
   })
   export class AppModule { }
   

6. Replace the content of the angular-example\src\app\app.component.html file with the following code that inserts the dx-report-viewer Angular component:

   app.component.html

   <dx-report-viewer [reportUrl]="reportUrl" height="800px">
   <dxrv-request-options [invokeAction]="invokeAction" [host]="hostUrl"></dxrv-request-options>
   </dx-report-viewer>
   

7. Replace the content of the angular-example\src\app\app.component.ts file with the following code:

   app.component.ts

   import { Component, ViewEncapsulation } from '@angular/core';
   
   @Component({
   selector: 'app-root',
   encapsulation: ViewEncapsulation.None,
   templateUrl: './app.component.html',
   styleUrls: [
       "../../node_modules/devextreme/dist/css/dx.light.css",
       "../../node_modules/@devexpress/analytics-core/dist/css/dx-analytics.common.css",
       "../../node_modules/@devexpress/analytics-core/dist/css/dx-analytics.light.css",
       "../../node_modules/devexpress-reporting/dist/css/dx-webdocumentviewer.css"
   ]
   })
   export class AppComponent {
   title = 'DXReportViewerSample';
   reportUrl: string = 'Products';
   hostUrl: string = 'https://localhost:54114/';
   // Use this line if you use an ASP.NET MVC backend
   //invokeAction: string = "/WebDocumentViewer/Invoke";
   // Use this line if you use an ASP.NET Core backend
   invokeAction: string = 'DXXRDV';
   }
   

   reportUrl

   A string that identifies a report. This string is passed to the server-side report name resolution services. You can create the ReportStorageWebExtension or IReportProvider descendant, and register it in your back-end application as a custom report name resolution service. For more information, review the following help topic: Open a Report in ASP.NET Core Application.

   invokeAction

   Specifies a route to the controller that handles requests in your back-end application. A controller with the DXXRDV route is an internal MVC controller that is added to the back-end application when the methods AddDevExpressControls and UseDevExpressControls are called in the Startup.cs file. You can implement a WebDocumentViewerController descendant and register it as a controller with a custom route. For the code sample, review the following help topic: ASP.NET Core Reporting Best Practices.

   hostUrl

   The back-end application’s URL.

   For more information on component options, review the following help topic: Document Viewer Client-Side Configuration in Angular Application.

8. Run the server-side project.

9. Use the command below to build and serve the application. You should run this command each time you make changes to the source files:

   ng serve
   

   Note

   For recent Angular versions (13 and later) you may have to compile the Angular project with the skipLibCheck option set to true, and increase the initial budget setting in the angular.json file up to 5mb to avoid compilation errors.

10. Open the http://localhost:4200/ location in the browser to see the test report.

Troubleshooting

Note

For recent Angular versions (13 and later) you may have to compile the Angular project with the skipLibCheck option set to true, and increase the initial budget setting in the angular.json file up to 5mb to avoid compilation errors.

When you start the application, you may encounter the following problems:

Page is blank

The Document Viewer page is blank. The following error message is displayed at the bottom of the page: The page is blank because the Document Viewer failed to load the report. Consult the developer for assistance. Use development mode for detailed information. If the page does not display the Document Viewer, press F12 to invoke DevTools and inspect the console messages.

Check the following:

• The backend application is up and running.
• The backend application runs on the port specified in the host setting of the Document Viewer component in your Angular project. Review the following help topic for more information: Determine the Host URL.
• The Angular application’s URI satisfies the CORS policy specified in your backend application. Review the following help topic for more information: Configure the Application.
• The Angular component’s reportName value matches an existing report. For the backend application it means that the Reports folder contains the reportName.repx file or the ReportsFactory.Reports dictionary contains the reportName entry (if backend application originated from the DevExpress template).
• The version of the DevExpress scripts (npm packages) should match the version of the server-side libraries (NuGet packages). You can enable Development Mode to check for library version mismatch on every request to the server. For more information, review the following help topic: Server-Side Libraries Version.

Review the following help topic for more information: Troubleshooting.