--- title: "Triggers and variables" description: "Make slides react - events, actions and conditions, variables for text, numbers and true/false, and where triggers live." canonical_url: "https://docs.ols.yonn.online/en/interact/triggers-and-variables" --- # Triggers and variables > Make slides react - events, actions and conditions, variables for text, numbers and true/false, and where triggers live. A **trigger** is a small rule that makes your course react: **when** something happens, **do** something. Example: when someone clicks the "Next" button, go to the next slide. You can add a condition (**if** the score is at least 8) and something to do **otherwise**. With triggers you build buttons, pop-ups, branching paths and little games, without writing any code. A **variable** is a named box that remembers a value while someone works through the course, for example their points, their name or whether a chapter is done. You work with these parts: - **Triggers tab**: the list of all triggers of the slide, its layers and the whole course. - **Trigger window**: where you set the action, the event and optional conditions. - **Variables window**: where you create and manage your variables. - **Built-in variables**: values the player fills in by itself, such as the score or the learner's name. ## Set up in 4 steps ### Open the Triggers tab In the properties panel on the right, click the lightning icon. That is the **Triggers** tab. It lists every trigger of the current slide. If you selected an object, you can also right-click it and choose **Add trigger**. ### Click Trigger Click the orange **Trigger** button at the top of the panel. The window **New trigger** opens. Under **Quick start** you can pick a ready-made template (for example **Button shows layer**), and all fields are filled in for you. More templates: [Trigger recipes](https://docs.ols.yonn.online/en/interact/trigger-recipes). ### Choose the action and the event Under **1 Action**, choose what should happen, for example **Show layer**. Under **2 Event**, choose when it happens (**When**, for example **User clicks**) and on which **Object**. Below every choice you see a short explanation with an example. ### Check the sentence and save At the top of the window, the trigger reads as a sentence, for example "Jump to the next slide when the user clicks Tile Networks". If it says what you want, click **Add trigger**. ![The Triggers tab of the sample slide Course menu: the slide on the left, the list of slide triggers with on/off switches on the right](https://docs.ols.yonn.online/screenshots/en/triggers-and-variables-panel.png) Press to play the current slide in the preview and click your button. Triggers work in the preview just like in the published course. ## The Triggers tab The tab groups triggers by where they are stored: **Slide triggers**, one group per layer (**Layer triggers**) and **Project triggers**. Inside a group, triggers are sorted by the object they belong to.
Element What it does
Trigger (orange button) Opens New trigger for the current slide or layer.
Filter icon Show only triggers of the selected objects . Handy on busy slides. Show all triggers again clears the filter.
Copy and paste icons Copy selected triggers and paste them into another slide or layer ( Paste triggers ).
Trash icon Delete selected triggers .
Plus in a group header Adds a trigger to exactly that group, for example to the project triggers.
Switch in front of a trigger Turns the trigger off without deleting it ( Turn trigger off (it is kept) ). Useful for testing.
Small heading above a trigger Your own Label , if you gave one.
Click on a trigger Selects it, for example to copy or delete it. A double-click opens Edit trigger .
Right-click or the small buttons on a trigger Edit trigger , Duplicate trigger , Delete trigger .
## The trigger window ![The New trigger window with Quick start, Action, Event, Conditions and Advanced](https://docs.ols.yonn.online/screenshots/en/triggers-and-variables-editor.png)
Element What it does
Sentence at the top Shows the whole trigger in plain words, so you can check it at a glance.
Quick start Six templates that fill in everything: Button shows layer , Go to the next slide , Change state on click , Count points (variable +1) , Close layer , Skip slide if variable is true .
1 Action What happens. Depending on the action, more fields appear, for example Layer , Slide or Variable .
2 Event When it happens, and for which Object .
3 Conditions Optional. The action only runs if the conditions are met. Condition adds one. Without conditions, the action always runs.
Advanced: Else action Something to do when the conditions are not met, for example show a "Wrong" layer instead of "Correct". Add a condition first.
Advanced: Label Your own name for the trigger list, for example "Navigation". Helps when a slide has many triggers.
Advanced: Save in Slide (only here), Layer (only while that layer is visible) or Project (on every slide).
Active Off: the trigger is saved but does nothing.
Add trigger / Save Saves the trigger. Cancel closes the window without changes.
## Actions An action is what the trigger does. In the window they are sorted into groups:
Group Actions
General Change state, Show layer, Hide layer, Show object, Hide object, Toggle visibility, Set focus, Play emphasis, Adjust variable, Start motion path
Navigation Next slide, Previous slide, Jump to slide, Jump to scene, Slide as lightbox, Close lightbox
Media Play media, Pause media, Stop media, Pause timeline, Resume timeline, Restart timeline, Jump on timeline
Background audio Play background audio, Pause background audio, Stop background audio, Set background audio
Project / results Submit interaction, Submit results, Review results, Reset results, Retry quiz, Print results, Exit course, Restart course, Complete course
More Open URL / file, Send email, Execute JavaScript
A **layer** is an extra level on top of a slide, for example a pop-up or a feedback message. A **lightbox** opens another slide as a window on top of the current one. ## Events An event is the moment the trigger starts.
Group Events
Mouse User clicks, User double-clicks, User right-clicks, Mouse hovers over, Mouse enters, Mouse leaves
Timeline Timeline starts, Timeline ends, Timeline reaches (a point in time or a cue point)
Objects and variables Media completes, State changes, Variable changes, Focus lost, Animation completes
Drag and drop Object dropped on, Object dragged over
Keyboard and gestures Key pressed, User swipes
Motion Object intersects, Intersection ends, Object enters the slide, Object leaves the slide
"Timeline starts" fires as soon as a slide or layer opens. Use it for things that should happen by themselves. ## Conditions
Condition What it checks Example
Variable The value of a variable: equals, does not equal, is less than, is less than or equal to, is greater than, is greater than or equal to, contains, does not contain, is empty, is not empty "Points" is greater than or equal to 8
Object state Whether an object is (or is not) in a state The checkbox is "Selected"
Intersection Whether two objects overlap The puzzle piece lies on the field
Window width How wide the learner's player window is, with presets for iPhone, iPad, laptop and large screens Narrower than 600 px: show a simpler layer
Several conditions are combined with **AND** (all must be true) or **OR** (one is enough). ## Variables Open to manage your variables. You can also create a new one right inside the trigger window: open the variable list and choose **New variable**.
Element What it does
Templates Ready-made variables: Count points , Save name , Chapter done , Count attempts .
New variable Creates an empty variable.
Name Letters, digits and _ , no spaces, not starting with a digit.
Type Number (points, attempts), Text (a name, an answer) or True/false (like a switch: chapter done or not).
Initial value The value at the start of the course.
Description A note for you: what is the variable for?
Used How often the variable is used in the course.
Built-in variables Read-only values from the player (see below).
To change a variable while the course runs, use the action **Adjust variable**. It can **Assign (=)**, **Add (+)**, **Subtract (-)**, **Multiply (*)**, **Divide (/)**, **Modulo (%)**, **Toggle (true/false)**, pick a **Random number** or **Append (text)**. To show a variable in a text box, write its name between percent signs: `%Name%`. Example: "Well done, %Name%!" ### Built-in variables The player fills these values by itself. You can show them in texts and use them in conditions, but you cannot change them. Examples: `Project.SlideNumber`, `Project.TotalSlides`, `Project.ProgressPercent`, `Slide.Title`, `Results.ScorePercent`, `Results.Passed`, `Learner.Name` and `Date.Today`. In the variable list of the trigger window you find all of them under **Built-in (read-only)**. `%Learner.Name%` shows the name Moodle reports, for example "Hello %Learner.Name%, you scored %Results.ScorePercent% percent." ## Project triggers Project triggers apply on every slide. Example from the sample course: when the H key is pressed, jump to the "Course menu" slide. Create one with the plus next to **Project triggers**, or choose **Project** under **Advanced: Save in**. ## JavaScript triggers The action **Execute JavaScript** runs your own code. You only need it for very special cases. JavaScript only runs when **Allow JavaScript** is on in , and only in the published package, never in the preview. After every import the switch is off again. An AI can never switch it on. ## If something doesn't work - **Nothing happens on click**: check the switch in front of the trigger (it must be on) and the **Object** under **Event**. Is the trigger stored on the right layer? - **The trigger fires on the wrong slide**: under **Advanced: Save in**, check whether it is a slide, layer or project trigger. - **The condition never matches**: open the preview with and click **Variables**. There you watch every value change live. - **The else action can't be switched on**: it needs at least one condition first. - **JavaScript does nothing**: it never runs in the preview. Publish the course and turn on **Allow JavaScript**. ## Sitemap See the full [sitemap](https://docs.ols.yonn.online/sitemap.md) for all pages.