Where to put utility functions in a React-Redux application?

Question

In a React-Redux application, I've got a state like this:

state = {
    items: [
        { id: 1, first_name: "John", last_name: "Smith", country: "us" },
        { id: 2, first_name: "Jinping", last_name: "Xi", country: "cn" },
    ]
}

which I render using a React component.

Now I need a function that gives me the "full name" of a person. So it's not just "first_name + last_name" but it depends on the country (for example, it would be "last_name + first_name" in China), so there's some relatively complex logic, which I would like to wrap in a function usable from any React component.

In OOP I would create a Person::getFullName() method that would give me this information. However the state object is a "dumb" one where sub-objects don't have any specialized methods.

So what is the recommended way to manage this in React-Redux in general? All I can think of is create a global function such as user_getFullName(user) which would take a user and return the full name, but that's not very elegant. Any suggestion?

Answer 1

I follow the approach of creating libraries for cases like this in my applications, and so far this works pretty well for me.

In this case, I would create a new module, e.g. {ComponentRoot}/lib/user.js which exports a function getFullName(user) or possibly getFullName(firstName, lastName, country), depending the circumstances.

Now it is just a matter of importing the module where you require the functionality, no global functions needed:

import React from 'react'
import {getFullName} from '../lib/user'

const Title = ({user}) =>
    <div>
        {getFullName(user)}
    </div>

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We place our library folder on the same level as the components folder etc., but whatever works best for you should do.