A Ulysses object triggers events as you move through steps, and you can listen to these to keep other parts of your interface in sync. Some steps receive additional data, which a callback can use.
Note that both the next and previous events fire before any actions are triggered. Use step for callbacks that should fire after the step completes.
start: Fires before the first step. No additional data is included.
next (step, feature): Fires each time story.next() is called, before actually moving to the next step. The included event has two members:
step: the index of current step (before changing)feature: the GeoJSON feature associated with the current step
previous (step, feature): Fires each time story.previous() is called, before actually moving to the previous step. The included event has two members:
step: the index of current step (before changing)feature: the GeoJSON feature associated with the current step
step (step, feature): Fires each time story.step(n) is called, after the step and associated action have fired (though not necessarily after all map updates have completed). The included event has two members:
step: the index of the current step (after changing)feature: the GeoJSON feature associated with the current step
end: Fires after the last step. No additional data is included.
destroy: Fires when story.destroy() method is called, just before removing event listers and running plugin cleanup functions. No additional data is included.
It's possible to define custom events. For example, an action might trigger a custom event to signal that it's finished, and a callback can listen for it.
let success = false;
story.on("success", e => {
success = e.success;
});
story.trigger("success", { success: true });