Скачать или смотреть Resolving Multiple API Calls in React Redux Saga

Learn how to fix the issue of multiple API calls in React Redux Saga. This guide provides a step-by-step solution and key insights to streamline your API interactions while preventing infinite loops.
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Resolving Multiple API Calls in React Redux Saga: A Complete Guide

When building applications with React and Redux, managing API calls effectively is crucial for optimal performance and user experience. One common issue developers face is the infinite API calls that occur when using the useEffect hook. This guide dives into this problem and provides a clear solution to prevent multiple invocations of API calls in your Redux Saga setup.

The Problem

Imagine you're trying to fetch a doctor's profile data using Redux Saga, and you find that the action is being called in a loop multiple times. This leads to infinite API calls, causing performance issues and potentially ruining the user experience. Here’s the scenario that often leads to this problem:

You call an action from useEffect, but the conditions for the effect are not correctly set, leading to the action being dispatched repeatedly without any termination condition.

Your Initial Setup

In the provided code sample, we see a few key pieces:

Reducer: It manages the state of the doctor profile.

Actions: These are dispatched to indicate the start and end of the API call.

Saga: It handles the asynchronous logic of fetching the doctor profile.

Component: This uses useEffect to trigger the API fetch.

The Solution

To solve the issue of infinite API calls, you need to refine the conditions within your useEffect hook. Here’s a breakdown of the solution:

Step 1: Update the useEffect Hook

You want to check if the API call has already been made or if a call is currently pending. This helps to ensure that you only fetch the data once the necessary conditions are met. Modify your useEffect like this:

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

Condition Explained:

!props.doctorProfile: This checks if the doctor profile has not been fetched yet.

!props.pending: This checks if the fetching is currently not in process.

Dependency Array: The array [props.doctorProfile, props.pending] ensures that the effect only runs when there’s a change in either of these properties.

Step 2: Ensure Correct State Mapping

Another critical aspect to look out for is the correct mapping of state to props. In your mapStateToProps, you should ensure that you are using the correct property names.

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

Summary of Changes

Add Conditional Logic: Implement a condition in the useEffect to prevent repeated API calls.

Correct Mapping: Ensure that you are mapping the state properties correctly from the reducer to avoid confusion between pending and isLoading.

By making these changes, you can ensure that your API calls are more controlled and that you're avoiding potential performance pitfalls caused by unbounded re-renders or unnecessary API requests.

Conclusion

Managing side effects, especially when dealing with API calls in a React-Redux application, requires clear logic and careful state tracking. By refining your useEffect conditions and ensuring proper state mapping, you can resolve issues of multiple API calls caused by unintended infinite loops. Implementing these best practices will not only enhance your application's performance but will also lead to a much smoother user experience.

If you have any more questions about Redux Saga or need further assistance, feel free to drop your queries in the comments below!