Different ways to call dispatch in Alt.js? - flux

Question

I have seen three different patterns for this and the alt docs do not make the distinction clear. If I have an action, how should I go about calling dispatch? Here are the three ways I have seen:
1. The action returns a function, which `dispatch` is passed into.
addPayment(args) {
return (dispatch) => {
dispatch();
// other action code
};
}
2. The action calls this.dispatch.
addPayment(args) {
this.dispatch();
// other action code
}
3. The action does not call dispatch.
addPayment(args) {
// other action code
}
It is not clear to me what difference there is between these three options, and it is especially unclear to me whether option #3 calls dispatch at all.
The bindActions method seems to associate actions with action handlers, so it would kind of make sense that a given action handler should be called automatically when the associated action is called, which would result in code that looked like option #3. But then, why would we ever need to explicitly call dispatch?
There is no tag for alt, so....yeah. Tagging it flux since that's the closest match.

Answer 1

Okay, as I understand things, approach #2 was patched out in later releases of alt and will now cause an error.
Approach #1 works fine when you want to trigger dispatch before your action completes. It's generally used when you have a handler that initiates a loading state in the UI, so you want to set things to loading while your action completes. Then you have separate success/failure actions (often just generated via alt's generateActions) with their own handlers which take care of what happens after the action completes.
Approach #3 is for when you want to trigger dispatch after your action completes. Here's a key bit from the alt docs that I missed:
You can also simply return a value from an action to dispatch.
So simply returning a value will call dispatch, and thus your action completes first. The docs also hasten to add:
There are two exceptions to this, however:
Returning false or undefined (or omitting return altogether) will not dispatch the action
Returning a Promise will not dispatch the action
So that bit provides a way to avoid triggering dispatch at all.