Please explain more about use case of redux thunk

[mschwarzmueller]

Please explain more about use case of redux thunk

[datntvn]

I had figured out

So, normally, action —> reducer (i.e, action is dispatched directly to reducer).

From the code that I mentioned above, it originally returned an object

		return {
			type: "SET_NAME",  
			payload: name. 
		}

Then we returned a function

return dispatch => {
	setTimeout(() => { 
		dispatch({ 
			type: "SET_NAME",  
			payload: name 
		});  
	}, 2000);  
};

This “return” means we return a fat-arrow function which received a parameter “dispatch”, similar to

return function(dispatch) { setTimeout(….) }

Then, another things came in. Normally, redux only accept “action” with type “object”, it does not accept “action” with type “function”. That’s why we use thunk.

So that, now, the follow becomes: action --> thunk --> reducer

Thunk is a middleware that it check type of the “action” (I believed), to know whether it is type “object” or type “function”. If the type is a “function” it execute the function.

That’s why our setTime function is executed. Then , after the timeOut event occurred, another function “dispatch” is executed.