{image && })
}
{riv && !image && }
{learnByExample ? "Learn by Example" : title}
{description && !learnByExample &&
{{description}
} {source && source.length > 0 &&{source.map((item, index) => { if (source.length == 1) { return <>Open the Rive file.; } if (index == 0) { return <>Open Rive file 1; } return <>, file {index + 1}; })}
}
{runtimesInOrder.map(currentRuntime => {
if (runtime && currentRuntime !== runtime) return;
return
}
## Listening for Changes to Inputs
The `update` function fires every time any input changes.
```lua theme={null}
function update(self: MyNode)
print('An update changed')
end
```
You can also listen for changes to specific properties:
```lua theme={null}
function handleMyStringChanged()
print('myString changed!')
end
function handleMyNumberChanged(myNumber: number)
print('myNumber changed!', myNumber)
end
function init(self: MyNode): boolean
-- handleMyStringChanged fires when self.myString changes
local myString = self.myString
myString:addListener(handleMyStringChanged)
-- Pass a parameter to the handleMyStringChanged callback
local myNumber = self.myNumber
myNumber:addListener(myNumber.value, handleMyNumberChanged)
return true
end
```
## View Model Inputs
View Model Inputs let your script read from and write to View Model properties. These properties can control any element in your Rive scene via (See [Data Binding](/editor/data-binding/overview)).
### Defining a View Model Input
Inside your script, declare a new input whose type matches the nested view model you want to reference (`Data.` + the name of your nested view model).
In this case, the Character view model type becomes `Data.Character`.
```lua theme={null}
type MyNode = {
-- This input expects a view model instance of type Character
character: Input
### Reading and Writing View Model Properties
Once connected, you can access the nested view model directly from your script:
```lua theme={null}
function moveCharacter(self: MyNode)
print('Current x: ', self.character.x.value)
self.character.x.value = 10
end
```
Because character is a view model instance, you can access all of its public properties:
```lua theme={null}
self.character.