API Aborting requests

When two requests target the same element, Unpoly will abort the earlier request.

This is to non-deterministic updates when two requests race to render the same fragment. Note that responses may or may not arrive in the same order as they were requested.

Controlling what's aborted

To control which requests are aborted, you may pass an { abort } option to rendering functions like up.follow(), up.submit() or up.render(). In your HTML you may use an [up-abort] attribute with the same values.

Don't abort anything

Pass { abort: false } to not abort any request.

If two requests would target the same fragment with { abort: false }, they will be rendered in the order of their response. If the first response removes the fragment targeted by the second request, it may cause the second request to fail or update a fallback target.

Aborting all requests

Pass { abort: 'all' } to abort all requests targeting any fragment on any layer.

Aborting requests on your layer

Pass { abort: 'layer' } to abort all requests targeting a fragment on the same layer as you.

Aborting conflicting requests

The default is { abort: 'target' }, which aborts earlier requests targeting fragments within your targeted fragments. Requests targeting other fragments are not aborted.

To visualize the effects of { abort: 'target' }, observe the layout below. The screen is split into a sidebar (#side) and a content area (#main). Contained within #main is a smaller fragment #box.

In this layout rendering with { abort: 'target' } has the following effect:

• Concurrent requests targeting #side and #main will not abort each other.
• When two requests target #main, the first request will be aborted by the second request.
• Rendering #main will abort an earlier request targeting #box.
• Rendering #box will not abort an earlier request targeting #main.

Preventing requests from being aborted

In some cases you may want to protect a request from being aborted through { abort }.
You may do so by passing an { abortable: false } option.

Aborting imperatively

To imperatively abort requests targeting a fragment or layer, use the up.fragment.abort() function.

There is also a low-level up.network.abort() function, which aborts requests matching arbitrary conditions.

Reacting to aborted requests

When aborting requests using the { abort } option or through up.fragment.abort(), the events up:fragment:aborted and up:request:aborted are emitted.

To simplify the registration of code when a fragment or its ancestor is aborted, use up.fragment.onAborted().

Aborting rules in layers

The following rules apply when opening or closing overlays:

• A request to open a new overlay will abort existing requests targeting the base layer's main element or its descendants.
• When two requests attempt to open a new overlay over the same base layer, the first request will be aborted by the second request.
• A request to open a new overlay is aborted when the base layer's main element is targeted by a second request.
• When a layer is closed, all pending requests targeting that layer are aborted. This is regardless of the { abort } option used.

Destroyed fragments are aborted

When a fragment is removed from the DOM (by rendering or explicit destroying), any request targeting this fragment (or its descendants) is aborted.

This is regardless of the { abort } option used for the render pass.