API Network requests

module up.network

This package implements an optimized HTTP client that is used for all requests made through Unpoly.

The HTTP client offers many quality-of-life improvements, for example:

• Requests may be cached to re-use responses and enable preloading. Cached content is revalidated after rendering, so the user never sees stale content.
• You may handle network issues, such as disconnects, flaky connections or low bandwidth.
• A progress bar is shown when requests take too long to finish. You may also implement a custom loading indicator.
• When two requests target the same element, Unpoly will abort the earlier request.
• Requests send additional HTTP headers that the server may use to optimize its response. For example, when updating a fragment, the target selector is automatically sent as an X-Up-Target header. The server may choose to only render the targeted fragment.
• Useful events like up:request:loaded or up:network:late are emitted throughout the request/response lifecycle.
• When too many requests are sent concurrently, excessive requests are queued. This prevents exhausting the user's bandwidth and limits race conditions in end-to-end tests.

Unpoly's HTTP client is used automatically when rendering, e.g. when following a link or submitting a form. To use the client from your own JavaScripts, use up.request().