What is the best way to handle a global variable in Vue.js?

Question

What is the best way to handle a global variable in Vue.js?

I am facing an issue with a mobile webview where a global config object is being injected:

Vue.prototype.$configServer = {
  MODE: "DEBUG",
  isMobile: false,
  injected: false,
  version: -1,
  title:"App",
  user: null,
  host: "http://127.0.0.1:8080"
}

Subsequently, the WebView injects this updated configuration:

Vue.prototype.$configServer = {
  MODE: "DEBUG",
  title: "App",
  version: "2.0",
  isMobile: true,
  injected: true,
  host: "http://127.0.0.1:8081"
}

As I try to utilize this configuration in my component:

const HomePage = {
  key: 'HomePage',
  template: '#HomePage',
  components: { toolbar },
  data() {
    return {
      items: [
        {name:"Login", link:"login"},
      ]
    }
  },
  computed:{
    config() {
      return Vue.prototype.$configServer
    }
  },
};

Despite updating the config object, the page does not reflect these changes. How can I ensure the page reacts to the updated configuration?

P.D: I have confirmed that the object is updated using Safari debug tools and also tested it on a local HTML file.

javascript ios vue.js uiwebview

Answer 1

Answer №1

Instead of storing the configuration in the prototype of Vue, consider adding it as a data option within the main Vue instance. This approach ensures that all configuration properties remain reactive, as outlined in the documentation.

When passing a plain JavaScript object to a Vue instance as its data option, Vue will automatically convert each property into getter/setters using Object.defineProperty.

This means that any updates made to your configuration properties will be detected and reflected by Vue.

Now, let's take a look at how this can be implemented in code:

new Vue() {
    data: { // The only place where 'data' is not a function
        configServer: {
            MODE: "DEBUG",
            isMobile: false,
            injected: false,
            version: -1,
            title: "App",
            user: null,
            host: "http://127.0.0.1:8080"
        }
    }
}

Once configured, you can access your settings directly from any component using $root. For example, this.$root.configServer.

And there you have it!

I trust this information proves useful.

Answer 2

Instead of storing the configuration in the prototype of Vue, consider adding it as a data option within the main Vue instance. This approach ensures that all configuration properties remain reactive, as outlined in the documentation.

When passing a plain JavaScript object to a Vue instance as its data option, Vue will automatically convert each property into getter/setters using Object.defineProperty.

This means that any updates made to your configuration properties will be detected and reflected by Vue.

Now, let's take a look at how this can be implemented in code:

new Vue() {
    data: { // The only place where 'data' is not a function
        configServer: {
            MODE: "DEBUG",
            isMobile: false,
            injected: false,
            version: -1,
            title: "App",
            user: null,
            host: "http://127.0.0.1:8080"
        }
    }
}

Once configured, you can access your settings directly from any component using $root. For example, this.$root.configServer.

And there you have it!

I trust this information proves useful.

Answer 3

Answer №2

There are 3 methods to achieve your desired outcome

1- Ensure that you import Vue into your component

import 'Vue' from vue
...
...
...
 computed:{
    config() {
      return Vue.prototype.$configServer
    }

2- If importing Vue is not preferred, you can directly access the prototype using proto from any instance.

computed:{
        config() {
          return this.__proto__.$configServer
        }

3- By adding the config to the prototype, you can access it directly from the Vue instance using this

computed:{
    config() {
      return this.$configServer
    }
  },

Choose whichever approach suits your style best.

Personally, I recommend opting for the third method as accessing the prototype of an instance can be considered an anti-pattern.

I trust this information proves beneficial.

Answer 4

There are 3 methods to achieve your desired outcome

1- Ensure that you import Vue into your component

import 'Vue' from vue
...
...
...
 computed:{
    config() {
      return Vue.prototype.$configServer
    }

2- If importing Vue is not preferred, you can directly access the prototype using proto from any instance.

computed:{
        config() {
          return this.__proto__.$configServer
        }

3- By adding the config to the prototype, you can access it directly from the Vue instance using this

computed:{
    config() {
      return this.$configServer
    }
  },

Choose whichever approach suits your style best.

Personally, I recommend opting for the third method as accessing the prototype of an instance can be considered an anti-pattern.

I trust this information proves beneficial.

What is the best way to handle a global variable in Vue.js?

Answer №1

Answer №2

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