Refactoring legacy AJAX code for mobile compatibility and performance
I'm writing unit tests and I'm relatively new to this, so bear with me... While refactoring a legacy application built with jQuery, I need to improve the AJAX handling to ensure better mobile compatibility. The current implementation is not optimized for performance, particularly on slower networks. Here's where I am: I'm using jQuery 3.5.1 for most of the AJAX calls, and I noticed that the existing setup lacks proper error handling and timeout configurations. My first approach involved wrapping the AJAX calls in a more modern pattern, but I’m still facing challenges with responsiveness. Here’s an example of the code I’m working with: ```javascript $.ajax({ url: '/api/data', method: 'GET', dataType: 'json', success: function(response) { // Process response console.log(response); }, error: function(xhr, status, error) { console.error('AJAX Error: ', status, error); } }); ``` To enhance the mobile experience, I’ve considered implementing a loading state to manage user expectations. However, I would like to avoid blocking the UI thread during the response wait time. Here’s an idea I’m exploring: ```javascript function fetchData() { $('#loading').show(); // Show loading indicator $.ajax({ url: '/api/data', method: 'GET', dataType: 'json', timeout: 5000, // Set a timeout of 5 seconds success: function(response) { $('#loading').hide(); // Handle response }, error: handleError }); } function handleError(xhr, status, error) { $('#loading').hide(); alert('Error: ' + error); } ``` In addition to this, I'm also looking for ways to manage caching more efficiently, especially since mobile users might navigate away and return frequently. I’ve heard about using `localStorage` for caching responses, but I’m unsure how to integrate that into the current flow without complicating the logic further. Also, performance tuning is critical. I’ve read about minimizing payload sizes and want to explore AJAX request optimizations such as only fetching necessary fields from the API. Any best practices or patterns that you can recommend for making AJAX more efficient in a mobile context? What strategies should I employ to ensure that my refactored code adheres to modern practices while still maintaining compatibility with older mobile devices? Any insights into leveraging modern JavaScript features, such as `async/await`, with jQuery would be greatly valued! For context: I'm using Javascript on macOS. Thanks in advance! This is part of a larger service I'm building. Any ideas what could be causing this? I'd love to hear your thoughts on this.