Aborting the dispatch

You may override the action's abortDispatch() function to completely prevent running the action under certain conditions.

warning

This is a complex power feature that you may not need to learn. If you do, use it with caution.

In more detail, if function abortDispatch() returns true, the action will not be dispatched: before, reduce and after will not be called.

Example

class UpdateUserInfo extends Action {

  // If there is no user, the action will not run.
  abortDispatch() {
    return state.user === null;
  }

...

Creating a base action

You may modify your base action to make it easier to add this behavior to multiple actions:

export abstract class Action extends KissAction<State> {

  allowWhenLoggedOut = false;   
  
  abortDispatch() {
  
    // The action should abort if it's not allowed to run while 
    // the user is logged out, and the user is indeed logged out. 
    let shouldAbort = !allowWhenLoggedOut && (state.user === null);        
    
    if (shouldAbort) {      
      navigateToHomePage();              
      return true; // Abort the action.      
    }        
    else {           
      return false; // Don't abort the action.
    } 
  }  
}

Now, only actions with allowWhenLoggedOut = true will be able to run when the user is logged out.

// This action to log in the user should 
// be able to run when the user is logged out.
class LogIn extends Action {
  allowWhenLoggedOut = true;         
  async reduce() { ... }
}

// This action that allows the user to send a message 
// should NOT be able to run when there is no user.
class SendMessage extends Action {           
  async reduce() { ... }
}