Storyline: How the Timeline-Starts Trigger Event Works

When you create a trigger based on the timeline-starts event for a slide, as shown below, the trigger repeats every time learners revisit the slide, even when you set it to resume its saved state.

For example, you might create triggers to disable the Next button when the slide's timeline starts and change the button to its Normal state when the timeline ends. You set the slide to resume to its saved state when revisited but find that the Next button constantly changes back to its disabled state when you view the slide again.

While this may seem unexpected, it's working as designed. In Storyline, the timeline-starts trigger event occurs every time the slide displays. So the timeline-starts trigger always executes when the learner revisits the slide, even if it resumes its saved state. Read on for ways to change this default behavior.

Changing the Default Behavior

There are ways to design a timeline-starts event that only occurs once. Check out the two suggestions below.

Use Restricted Navigation

Instead of using triggers to control the state of the Next button, use restricted navigation to initially lock the Next button. When learners revisit a slide, the Next button remains unlocked.

This option is ideal when you want to prevent learners from skipping to the next slide but don’t want them to get stuck when revisiting the previous slide.

Use a Conditional Trigger

Use trigger conditions to prevent the timeline-starts trigger from executing when the learner revisits the slide. Follow these steps:

1. Configure the slide to resume its saved state.
2. Create a new true/false variable with an initial value of False.
3. Add a condition to your timeline-starts trigger (e.g., change the state of an object or adjust the variable’s value) so that it only executes when the variable’s value is False.
4. Add another trigger that changes the variable's value to True when the timeline ends.

This option is ideal when you must use the timeline-starts trigger but don’t want the same event to repeat when learners revisit the slide.