Retry the Image Loading

Managing the retry mechanism when an error happens during loading.

Overview

Use KingfisherOptionsInfoItem/retryStrategy(_:) along with a RetryStrategy implementation to easily set up a retry mechanism for image setting operations when an error occurs.

This combination allows you to define retry logic, including the number of retries and the conditions under which a retry should be attempted, ensuring a more resilient image loading process.

Built-in Retry Strategies

Kingfisher provides two built-in retry strategies to handle different scenarios:

DelayRetryStrategy

DelayRetryStrategy is a time-based retry strategy that allows you to specify the maxRetryCount and the retryInterval to easily configure retry behavior. This setup enables quick implementation of a retry mechanism:

let retry = DelayRetryStrategy(
  maxRetryCount: 5,
  retryInterval: .seconds(3)
)
imageView.kf.setImage(with: url, options: [.retryStrategy(retry)])

This implements a retry mechanism that attempts to reload the target URL up to 5 times, with a fixed 3-second interval between each try.

Other retry interval

For a more dynamic approach, you can also select .accumulated(3) as the retry interval results in progressively increasing delays between attempts, specifically 3 -> 6 -> 9 -> 12 -> 15 seconds for each subsequent retry. Additionally, for ultimate flexibility, .custom allows you to define a unique pattern for retry intervals, tailoring the retry logic to your specific requirements.

NetworkRetryStrategy

NetworkRetryStrategy is a network-aware retry strategy that handles network connectivity issues. It only retries when the network becomes available after a disconnection, this is suitable to handle unstable user connection.

// Basic usage - retries immediately when network becomes available
let networkRetry = NetworkRetryStrategy()
imageView.kf.setImage(with: url, options: [.retryStrategy(networkRetry)])

// With timeout - stops waiting after specified duration
let networkRetryWithTimeout = NetworkRetryStrategy(timeoutInterval: 30.0)
imageView.kf.setImage(with: url, options: [.retryStrategy(networkRetryWithTimeout)])

Custom Retry Strategies

If you need more control for the retry strategy, implement your own type that conforms to RetryStrategy.

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