Best way to define common constants in Vue.js? [closed]

问题

I'm developing a couple of Vue apps using single file components. I find quite a few of my components require common config information, for example an object containing delivery methods which I might define like this:

const DeliveryMethods = {
  DELIVERY: "Delivery",
  CARRIER: "Carrier",
  COLLATION: "Collation",
  CASH_AND_CARRY: "Cash and carry"
}

What would be the neatest and simplest way to make that available to my components? At the moment, I have done it with a file 'config.js', as below:

export default {

  DeliveryMethods: {
    DELIVERY: "Delivery",
    CARRIER: "Carrier",
    COLLATION: "Collation",
    CASH_AND_CARRY: "Cash and carry"
  }

}

In my components where I need it, I have import config from 'src/config.js', and where I want to use one of these, I'll refer to e.g., config.DeliveryMethods.CASH_AND_CARRY. This seems to me rather long-winded and repetitive, though, and I'd prefer to be able to use just DeliveryMethods.CASH_AND_CARRY instead of config.DeliveryMethods.CASH_AND_CARRY. What do others use to accomplish this?

回答1:

delivery-methods/index.js

const DELIVERY = "Delivery"
const CARRIER = "Carrier"
const COLLATION = "Collation"
const CASH_AND_CARRY = "Cash and carry"

export default {
  DELIVERY: DELIVERY,
  CARRIER: CARRIER,
  COLLATION: COLLATION,
  CASH_AND_CARRY: CASH_AND_CARRY
}

Usage

import DeliveryMethods from './path/to/delivery-methods'

console.log(DeliveryMethods.CARRIER)

Or:

config.js

export default Object.freeze({
  DELIVERY: "Delivery",
  CARRIER: "Carrier",
  COLLATION: "Collation",
  CASH_AND_CARRY: "Cash and carry"
})

Usage:

import DeliveryMethods from './path/to/delivery-methods'

console.log(DeliveryMethods.CARRIER)

回答2:

Thanks, this and subhaze's comment pointed me in the right direction. DeliveryMethods isn't the only constant I'd want to use, so export default doesn't work if I want to have all my constants in a single file for ease of maintenance. What I've done is this:

export const DeliveryMethods = {
    DELIVERY: "Delivery",
    CARRIER: "Carrier",
    COLLATION: "Collation",
    CASH_AND_CARRY: "Cash and carry"
};

In my components I have import {DeliveryMethods} from 'src/config.js', which allows me to simply use e.g. DeliveryMethods.COLLATION. I can export/import any number of constants clearly and simply. Still feeling my way round Javascript modules!

LATER: Following WaldemarIce's suggestion, I have changed this to:

export const DeliveryMethods = Object.freeze({
    DELIVERY: "Delivery",
    CARRIER: "Carrier",
    COLLATION: "Collation",
    CASH_AND_CARRY: "Cash and carry"
});

That works better.

来源：https://stackoverflow.com/questions/47597384/best-way-to-define-common-constants-in-vue-js

标签

Vue.js