Glossary A–ZLetter R
Rule-based playlist
A rule-based playlist only plays content when defined rules are met, for example a data value, a device group, a sensor status or the weather.
The player checks the conditions itself and skips entries whose rule does not currently apply.
A café, for instance, shows iced coffee above 25 degrees and hot chocolate when it rains, without anyone switching over. A chain uses a single list for all branches and shows or hides content based on attributes such as region, format or product range. Conditions can be combined with and and or. SMIL has its own conditional expressions for this, which the player evaluates at run time.
Operators should make sure that there is always something to show: if none of the conditions apply at the same time, the screen otherwise stays blank, so every list needs a fallback. The more rules there are, the harder it is to predict what a particular screen is currently showing; a preview per device helps. If data for a condition is unavailable, it should be decided whether the entry is then shown or skipped.