FAQ¶

Why lifecycle callbacks are not called on iOS (or any other non-Android platform)?¶

On non-Android platforms the Lifecycle should usually be controlled manually. This can be done by creating an instance of LifecycleRegistry, passing it to DefaultComponentContext, and then controlling the LifecycleRegistry based on platform-specific lifecycle events. Please refer to the sample project to learn about platform integrations.

However, there are convenient APIs for some platforms.

Lifecycle on iOS¶

If the root component lives in the application scope (i.e. Decompose is used in the entire application, not partially in one screen), then ApplicationLifecycle API from Essenty can be used. ApplicationLifecycle can be destroyed manually if needed, e.g. when the root component is created in a UIViewController and the screen is closed.

Lifecycle on Compose for Desktop (JVM)¶

There is the LifecycleController API available on Compose for Desktop.

Error "Another supplier is already registered with the key"¶

This exception is thrown by StateKeeper when its register method is called second time with the same key.

• If you are using Compose, make sure that you create the root component context and component outside Compose. See the docs. Otherwise, a second instance can be created if the root Composable function re-composes.
• Don't use get() = for navigation properties (such as val stack: Value<ChildStack<...>>), just assign the value to the property.

  - val stack: Value<ChildStack<...>> get() = childStack(...)
  + val stack: Value<ChildStack<...>> = childStack(...)
  

• If you are using more than one childStack in one component (or more than one navigation model of the same kind in one component), then please supply the key argument for every such function.

  val stack1: Value<ChildStack<...>> = childStack(key = "stack1", ...)
  val stack2: Value<ChildStack<...>> = childStack(key = "stack2", ...)
  

Error "Configurations must be unique"¶

This exception is thrown when duplicated component configurations are detected by a navigation model (e.g. Child Stack). Duplicates are checked according to the equals method, which all configurations must be properly implementing. See the docs for more information.

• Prefer pushNew function instead of push when showing a component on a button click, it will properly handle accidental double clicks.
• Prefer pushToFront to prevent duplicated components with the same data (configurations) in the stack.