# JSONata
There are three functions added for JSONata expressions within the Home Assistant nodes.
$entity()returns the entity that triggered the node$prevEntity()returns the previous state entity if the node is an event node$entities()returns all entities in the cache$entities(entity_id)returns a single entity from cache matching passed in entity_id
Expose Lodash (opens new window) functions
$sampleSize(collection, [n=1])https://lodash.com/docs/#sampleSize (opens new window)Gets n random elements at unique keys from collection up to the size of collection.
$randomNumber([lower=0], [upper=1], [floating])https://lodash.com/docs/#random (opens new window)Produces a random number between the inclusive lower and upper bounds. If only one argument is provided a number between 0 and the given number is returned. If floating is true, or either lower or upper are floats, a floating-point number is returned instead of an integer.
When JSONata appears in the conditional dropdown it expects the expression to return a boolean, true or false.
When it is chosen with a conditional, not JSONata it will return a value of the evaluated expression that will be checked against the conditional chosen.
# Examples
- Increase lights brightness with remote
- Notification of lights left on when leaving home
- OR conditional for the events: state node
Also see: