up.layer up:layer:open

DOM event

This event is emitted before an overlay is opened.

At emission time, the overlay is not yet part of the layer stack. The overlay's elements have not yet been placed in the DOM. Listeners can prevent this event to prevent the overlay from opening.

The event is emitted on the document.

Opening overlays

Changing layer options

Listeners can inspect and manipulate options for the overlay that is about to open.

For example, to give overlays the CSS class .warning if the initial URL contains the word "confirm":

up.on('up:layer:open', function(event) {
  if (event.layerOptions.url.includes('confirm')) {
    event.layerOptions.class = 'warning'
  }
})