Action Registry

The first step in adding Trrack to your application is to create a action registry using the Registry class.

const registry = Registry.create();

Now actions can be registered in the registry. Actions are the only way Trrack knows that something has happened and it has to update the provenance graph.

Action Types

There are two types of actions that can be registered.

State Action

State actions get the current state of the application as an argument and can modify it based on the payload, which is the second argument. This is similar to redux reducers (opens in a new tab).

// Action which updates the `count` key in the state by desired value.
const incrementAction = registry.register(
  'increment-action', // Action name
  // Action handler which receives the current state and a payload.
  (currentState: State, payload: number) => {
    currentState.count += payload;
  }
);

When state actions are executed, the changes to the state are stored in a new provenance node.

Trrack Action

The other type of action that is supported is called a Trrack action. These actions do not modify the application state, but execute any arbitrary side effect.

When trrack action is executed, Trrack keeps a record of execution and the payload of the action. You need to provide a undo counterpart to each action to allow Trrack to undo the action.

An trrack action can be set as undo for itself.

const arr = [1, 2, 3, 4];
 
registry.register('sort', (sortBy: 'asc' | 'dsc') => {
  if (sortBy === 'asc') arr.sort();
  if (sortBy === 'dsc') arr.sort().reverse();
 
  return {
    undo: {
      type: 'sort',
      payload: sortBy === 'asc' ? 'dsc' : 'asc',
      meta: {
        hasSideEffects: true,
      },
    },
  };
});