Triggers using widgets

This functionality allows a user to interact with a widget embedded in an iframe to trigger playback content dynamically in different regions of the playlist. The widget communicates with the SMIL player using CustomEvent interface and dispatchEvent function.

Trigger setup

<triggers>
    <trigger id="trigger1" condition="or">
        <condition origin="widget" data="data_trigger_1"/>
    </trigger>
    <trigger id="trigger2" condition="or">
        <condition origin="widget" data="data_trigger_2"/>
    </trigger>
    <trigger id="trigger3" condition="or">
        <condition origin="widget" data="data_trigger_3"/>
    </trigger>
</triggers>

• id = unique identifier for the trigger, used to reference the trigger in the playlist
• condition = logical operator to combine multiple conditions
• origin = marks trigger as a widget trigger to use sync widget functionality
• data = trigger identifier sent from the widget

For sub-region setup see Sub-regions, for trigger duration (dur/repeatCount) see Trigger duration, and for cancellation (end) see Cross-trigger cancellation.

Define content triggered by the widget trigger

<par>
    <seq begin="trigger1" repeatCount="indefinite">
        <img src="https://demo.signageos.io/smil/zones/files/img_1.jpg"
             dur="5s" region="video">
        </img>
        <img src="https://demo.signageos.io/smil/zones/files/img_3.jpg"
             dur="5s" region="video">
        </img>
    </seq>
</par>

Function to send information from the widget to the SMIL player

• The widget sends the trigger data identifier to the SMIL player using the CustomEvent interface and dispatchEvent function. Using the name of the event sosEvent is mandatory.

function sendMessage(data) {
	// data has to be one of the data fields defined in the SMIL file in triggers definition,
	// for example "data_trigger_1"
	const event = new CustomEvent('sosEvent', {
		detail: data,
	});
	window.parent.dispatchEvent(event);
}

The detail value must be a plain string matching one of the data values declared in <triggers> — object payloads are ignored. Repeated events for a trigger that is already playing are idempotent (they extend the trigger's dur countdown rather than starting a second copy).