Скачать или смотреть How to Retry Failed API Calls in a JavaScript for...of Loop Using Async Iteration

Learn how to handle and retry failed API calls with JavaScript's async iterators, especially when working with the Notion JS SDK.
---
This video is based on the question https://stackoverflow.com/q/75453504/ asked by the user 'linkyndy' ( https://stackoverflow.com/u/433940/ ) and on the answer https://stackoverflow.com/a/75454256/ provided by the user 'Moritz Ringler' ( https://stackoverflow.com/u/4883195/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Retry failed API call in for...of loop

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Handling Failed API Calls in JavaScript's Async Iterators

When working with APIs in JavaScript, encountering errors is common. These can range from connectivity issues to rate limiting by the API provider. This guide is dedicated to addressing a specific challenge: how to retry failed API calls within a for...of loop that utilizes async iteration.

The Problem

Imagine you are building an application using the Notion JS SDK, which requires you to iterate through paginated API responses. However, API calls can fail for various reasons, often leading to frustration when trying to implement error handling. As a developer transitioning from Ruby, you might be missing the familiar retry feature found in Ruby's rescue blocks.

Here's a pseudo example of your initial attempt:

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

In this code, catching errors inside the for await...of loop doesn't work as expected because the exception arises from the loop itself, not the body of the loop.

The Solution

To effectively manage errors and implement a retry mechanism, we can manipulate the async iterator directly and handle errors in a controlled manner.

Step-by-Step Breakdown

Manual Iterator Handling: Instead of relying on the for await...of loop to manage the flow, you can call Iterator.next() manually. This allows for better control over what to do during an error.

Error Handling and Retry Logic: Use try...catch blocks to catch errors. If an error occurs, handle it and optionally retry the call.

Here's a revised implementation:

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

Alternative Using for await...of

If you prefer the readability of the for await...of syntax, you can still implement retries effectively while keeping track of exceptions:

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

Conclusion

Handling failed API calls gracefully is crucial for developing robust applications. By manually controlling your async iteration with Iterator.next() or with structured retries using for await...of, you can ensure your application remains resilient against API errors.

Summary

Understand API failures and how to catch them effectively using JavaScript.

Utilize manual control over async iterators to enhance error handling and retries.

Implement structured retry logic in your loop to improve the reliability of your application.

By applying these techniques, you'll be able to create safer and more resilient API interactions in your JavaScript projects. Happy coding!