Migrating from Alt

alt-ng is based in the original implementation of Alt, an open source project by Josh Perez. For existing Alt applications that are being migrated, these are the main differences that you should be aware of:


  • alt-ng requires importing specifically the files that you use (e.g. import Store from 'alt-ng/Store'). This avoids including AltContainer in your application if you are not using it.


  • flush, save and load have been removed from Alt. We encourage people to implement their own solutions adapted to their needs (see Store initial state).
  • The config argument of the Alt constructor has been removed.
  • alt.createAsyncActions and alt.generateActions hae been merged into a single alt.createActions method.


  • When an Action returns a Promise, it will run and the value resolved by the Promise will be dispatched to the Store handlers. The action method will still return the Promise, which can be chained for testing purposes.
  • Actions are not classes, but plain JSON objects.
  • The namespace is now required when creating Actions, and the order of arguments in alt.createActions is switched (namespace is now the first attribute).


  • The bootstrap feature has been replaced with a Store initial state pattern
  • Lifecycle events in Stores have been removed with no replacement (Store.on() has been removed). Specifically, error handlers used to be able to silently catch exceptions while dispatching.
  • Stores now must extend alt-ng/Store
  • The displayName is now required when creating Stores, and the syntax of arguments in alt.createStore has changed.
  • Stores are now instantiated manually before calling alt.createStore(), and all state must be stored in the state attribute.


  • alt-ng will inject Storage state directly as properties to child entities, where alt used to inject the stores themselves.
  • The original AltContainer implementation would detect if there is a single child, and generate no parent Element in this case. alt-ng will always generate a parent element.
  • Originally AltContainer would pass any properties to its children. This implementation will only pass Store state, and use the properties only on the parent Element.