How to pass Parameters in a nested Function in Javascript

Question

Our code currently has a function that calls a toast message popup while saving an object to the database.

export function addAnimal(animalObject) {
  return function(dispatch) {
    showToastNotification(() => {
      return addAnimal(animalObject);
    }, dispatch);
  };
}


function showToastNotification(handleToastSave, dispatch) {    
  return handleToastSave()
    .then(() => {
      showMessage("this was a success")(dispatch);
    })
    .catch(() => {
      showMessage("Something went wrong!")(dispatch);
    })
    .finally(() => {
      saveMode(false)(dispatch);
    });
}

My question is I want to pass a message string as a parameter to the showToastNotification like this:

export function addAnimal(animalObject) {
  return function(dispatch) {
    showToastNotification(("successfully added animal") => {
      return addAnimal(animalObject);
    }, dispatch);
  };
}

function showToastNotification(message, handleToastSave, dispatch) {    
  return handleToastSave()
    .then(() => {
      showMessage(message)(dispatch);
    })
    .catch(() => {
      showMessage("Something went wrong!")(dispatch);
    })
    .finally(() => {
      saveMode(false)(dispatch);
    });
}

This doesn't work. I'm not super familiar with how the fat arrow in this function works. Would it be possible to pass a prop to showToastNotification?

IceMetalPunk · Accepted Answer · 2019-10-03 20:35:52Z

2

You're putting the string where the parameters of the callback would be, instead of as the first argument to the actual showToastNotification function. Just move it to the right place:

showToastNotification("successfully added animal", () => {
  return addAnimal(animalObject);
}, dispatch);

answered Oct 3, 2019 at 20:35

IceMetalPunk

5,6074 gold badges21 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

lost9123193 Over a year ago

do you know where's the best place I can find resources about fat arrow functions like this? I still don't 100% understand the syntax

IceMetalPunk Over a year ago

If you Google "ES6 arrow function" you can find plenty. But it's fairly simple. Where you would previously create an anonymous function by doing function(param1, param2, param3) { /* Code here */ } you can now write it like (param1, param2, param3) => { /* Code here */ } Instead. If you just want the function to be a single line that returns the result of that line, you can remove the {} and the word "return" if you like; (p1, p2, p3) => p1+p2+p3 will add the parameters and return the sum, for instance. In arrow functions, this refers to the outer scope instead of the function scope.

Collectives™ on Stack Overflow

How to pass Parameters in a nested Function in Javascript

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related