Call a Web API

Time to say Hello to an Omnia Fx Web API.

In this part of the tutorial, you will make a client-side component call to a Web API and then display a response message.

Note: The following example will build upon what we have done in Create an extension, so make sure you've been through it.

Sample Source Code

Step 1. Create a controller

Create a new folder called Controllers under ..\HelloOmniaFx.Web\.

Inside the newly created folder, create a new item of typ API Controller Class with the name TestController.

Add a GET method in the controller

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;

namespace HelloOmniaFx.Web.Controllers
    public class TestController : ControllerBase
        public string Hello(string name)
            return $"Hello {name}, nice to meet you. I am Omnia Fx Web API";

Step 2. Call the Web API

Open the file HelloOmniaFxComponent.tsx.

Inject a HttpClient instance

export default class HelloOmniaFxComponent extends VueComponentBase implements IWebComponentInstance, IHelloOmniaFxComponent {

    //Inject HttpClient
    @Inject<HttpClientConstructor>(HttpClient, {
        configPromise: HttpClient.createOmniaServiceRequestConfig('[web-service-id]')
    }) private httpClient: HttpClient;


Note: Replace [web-service-id] with the guid defined in registerManifest in the omnia.service.ts file.

Tip: Use the built-in Quick Actionsopen in new window in Visual Studio to automatically import required modules from omnia fx npm. Tip: If Quick Actions can't help you with the needed imports, you can always check the source code of the sample project.

Add new properties and function:

private name = '';
private responseMsg = '';
private waiting = false;

callWebAPI() {
    this.waiting = true;
    this.httpClient.get<string>('/api/test?name=' + => {
        this.waiting = false;
        this.responseMsg =

Update the render function:

render(h) {
    return (
        <div class={this.HelloOmniaFxComponentClasses.container}>
            <div class='text-xs-center'>
                <div><v-text-field label="Name" v-model={}></v-text-field></div>
                <div><v-btn flat loading={this.waiting} onClick={this.callWebAPI}>Send</v-btn></div>

Step 3. Test the result

Build and run the project.

Enter your name in the text box, and click the send button.

Wow, your solution has got a backend up and running!

Next Part