Скачать или смотреть Displaying a Loading Spinner in Angular During API Requests

Learn how to implement a loading spinner in your Angular application to enhance user experience during API requests triggered by search terms.
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How to Show a Loading Spinner During API Requests in Angular

When developing an Angular application, ensuring that your users have a seamless experience during data retrieval can significantly enhance the usability of your application. One common scenario is showing a loading spinner when a user searches for data, allowing them to gauge that their request is being processed. In this guide, we’ll explore how to implement a loading spinner that appears whenever an API request is initiated upon entering search terms in a search bar.

The Problem

You have an input field for users to enter a search term. After the user inputs a search term, an API request is triggered to retrieve the corresponding data. However, currently, there is no visual feedback indicating that a request is being processed. This can lead to confusion as users may think that the application is unresponsive. Therefore, it’s important to implement a loading spinner that becomes visible during API requests.

A Step-by-Step Solution

Now that we’ve identified the problem, let’s dive into how we can show a loading spinner during these periods of data fetching. We have the following components in our Angular application:

TypeScript Code: This is where we define our component and implement logic for fetching data.

HTML Code: This is where we display our loading spinner, based on the state defined in TypeScript.

Updates to TypeScript Code

To begin with, we need to modify the component’s TypeScript file to control the visibility of the spinner. Here’s how this can be done:

[[See Video to Reveal this Text or Code Snippet]]

Important Changes Explained

this.showSpinner = true;: This line activates the loading spinner right before making the API request. This ensures that the spinner is displayed to users as soon as the search term changes.

this.showSpinner = false;: After retrieving the data from the API, we hide the spinner. This indicates to users that the data is now available.

Updates to HTML Code

Now, we need to update the HTML file to ensure the spinner is shown correctly based on the value of showSpinner. This can be achieved using Angular’s structural directives:

[[See Video to Reveal this Text or Code Snippet]]

HTML Structure Overview:

<ng-template # loading>: This is a template that contains the loading spinner component.

*ngIf="!showSpinner; else loading": This conditionally renders the main content. If showSpinner is false, the main content is displayed; if true, it renders the loading template.

Conclusion

Implementing a loading spinner in your Angular application is a fantastic way to enhance user experience during data fetching. By following the steps outlined above, you can easily manage the visibility of the spinner based on the application's state. Users will appreciate the feedback provided as they wait for their requests to be processed.

Enhancing your application’s UI with visual cues such as loading spinners not only improves usability but also engages users more effectively. So next time you build a search feature, ensure you include that loading indicator!