Avoiding Angular Duplicate HTTP Requests with the RxJS shareReplay Operator

In modern web development, Angular has emerged as a powerful and popular framework for building dynamic and responsive applications. One of the common challenges faced by Angular developers is managing duplicate HTTP requests triggered by multiple subscribers. These duplicate requests can result in inefficient network usage and unnecessary server load. Fortunately, the RxJS library, which is an integral part of Angular, provides a solution to this problem through the <code>shareReplay</code> operator. In this article, we will explore how the <code>shareReplay</code> operator can help us avoid duplicate HTTP requests in Angular applications. <img alt="" src="https://miro.medium.com/v2/resize:fit:504/0*KadUWpk-4_v4glP-.jpg" style="height:381px; width:504px" /> Understanding the Problem: Angular services are often responsible for making HTTP requests to fetch data from APIs. In a typical scenario, multiple components may need the same data, leading to multiple subscriptions to the same service method. This situation can arise when components are initialized at different times or when the same component is used multiple times on a page. Consequently, each component triggers an individual HTTP request, even if the data is already available from a previous request. Duplicate requests not only consume additional network bandwidth but also result in redundant server-side processing. This can lead to slower application performance, increased latency, and potential API rate limits. To illustrate the problem, let’s consider an example. <a href="https://blog.bitsrc.io/avoiding-angular-duplicate-http-requests-with-the-rxjs-sharereplay-operator-773ba1b4ad5e">Click Here</a>