up.layer up:layer:open

DOM event

This event is emitted before an overlay is opened.

The overlay is not yet part of the layer stack and has not yet been placed in the DOM. Listeners may prevent this event to prevent the overlay from opening.

The event is emitted on the document.

Changing layer options

Listeners may 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'
  }
})