Encountering an error where the property '$options' is being attempted to be read from an undefined source while creating an external JavaScript

Question

Encountering an error where the property '$options' is being attempted to be read from an undefined source while creating an external JavaScript

I am in the process of configuring a global head setup in Nuxt for my application, which will be customized by some subpages. The content within this global head needs to be translated.

To achieve this, I have created a file called seoHead.js with the following code:

import Vue from "vue";

export const $t = (sign) => Vue.prototype.$nuxt.$options.i18n.t(sign);

export default {
  title: $t("seoGlobal.title"),
  meta: [
    { charset: "utf-8" },
    { name: "viewport", content: "width=device-width, initial-scale=1" },
    {
      hid: "description",
      name: "description",
      content: $t("seoGlobal.description"),
    },
    {
      hid: "ogSiteName",
      name: "og:site_name",
      content: "Test Page",
    },
    {
      hid: "ogTitle",
      name: "og:title",
      content: $t("seoGlobal.ogTitle"),
    },
    (...)
  ],
};

I then import and utilize this data in my index.vue and other pages like so:

import seoHead from "~/constants/seoHead";

export default {
  head() {
    const metaI18n = this.$nuxtI18nSeo();
    const currentPath = process.env.LP_URL + this.$router.currentRoute.fullPath;
    return {
      ...seoHead,
      meta: [
        {
          hid: "ogLocale",
          name: "og:locale",
          content: metaI18n.meta[0].content,
        },
        {
          hid: "ogLocaleAlternate",
          name: "og:locale:alternate",
          content: metaI18n.meta[1].content,
        },
        {
          hid: "ogUrl",
          name: "og:url",
          content: currentPath,
        },
      ],
    };
  },
(...)

However, I have encountered an issue with the error message

Cannot read property '$options' of undefined

. This is puzzling to me as I have already used the code

export const $t = (sign) => Vue.prototype.$nuxt.$options.i18n.t(sign);

in another JavaScript file. Does anyone have insights on why this error is occurring? Is there a better approach to translating global head options?

javascript vue.js nuxt.js nuxt-i18n

Answer 1

Answer №1

After some discussion in the comments, it appears that there is a timing issue related to the Nuxt lifecycle and your component. When your component seoHead.js is imported, Nuxt has not yet injected its $nuxt object into Vue. To work around this issue, one solution is to delay the execution of your $t function (which accesses $nuxt):

Modify your component to export a function that returns the object instead of directly exporting the object:

export default function() {
  return {
    title: $t("seoGlobal.title"),
    // ...
  }
}

In index.vue, update your head function to call seoHead when spreading it:

return {
  ...seoHead(),
  // ...

This way, the code that accesses $nuxt will be executed later – not during the import of seoHead, but only when the head function is executed. By then, hopefully, the Nuxt lifecycle has completed its initialization work and the necessary object is available.

It's important to note that this workaround is temporary; if you were to call head immediately in index.vue, the same error would occur. If integrating properly into the Nuxt lifecycle proves challenging, I recommend adding a safety measure to your translation function:

const $t = (sign) => Vue.prototype.$nuxt 
  ? Vue.prototype.$nuxt.$options.i18n.t(sign)
  : sign

This function will return the i18n key if the necessary infrastructure is not yet available. It may not be ideal, but it's better than causing an exception ;)

Alternatively, consider importing your i18n functionality directly without relying on Nuxt at all. This eliminates any dependencies on the infrastructure altogether, which is a much cleaner approach.

Answer 2

After some discussion in the comments, it appears that there is a timing issue related to the Nuxt lifecycle and your component. When your component seoHead.js is imported, Nuxt has not yet injected its $nuxt object into Vue. To work around this issue, one solution is to delay the execution of your $t function (which accesses $nuxt):

Modify your component to export a function that returns the object instead of directly exporting the object:

export default function() {
  return {
    title: $t("seoGlobal.title"),
    // ...
  }
}

In index.vue, update your head function to call seoHead when spreading it:

return {
  ...seoHead(),
  // ...

This way, the code that accesses $nuxt will be executed later – not during the import of seoHead, but only when the head function is executed. By then, hopefully, the Nuxt lifecycle has completed its initialization work and the necessary object is available.

It's important to note that this workaround is temporary; if you were to call head immediately in index.vue, the same error would occur. If integrating properly into the Nuxt lifecycle proves challenging, I recommend adding a safety measure to your translation function:

const $t = (sign) => Vue.prototype.$nuxt 
  ? Vue.prototype.$nuxt.$options.i18n.t(sign)
  : sign

This function will return the i18n key if the necessary infrastructure is not yet available. It may not be ideal, but it's better than causing an exception ;)

Alternatively, consider importing your i18n functionality directly without relying on Nuxt at all. This eliminates any dependencies on the infrastructure altogether, which is a much cleaner approach.

Answer 3

Answer №2

It sounds like incorporating a mixin would be beneficial in this situation.

export default {
  title: $t("seoGlobal.title"),
  meta: this.computedMeta,
  computed:{
    computedMeta(){
      return [....] // an array of objects is stored in 'meta'
   }
  }
  methods:{
   yourMethod(sign){
     return this.$nuxt.$options.i18n.t(sign);
   }
  }
};

Simply import it as a mixin into the necessary file.

Answer 4

It sounds like incorporating a mixin would be beneficial in this situation.

export default {
  title: $t("seoGlobal.title"),
  meta: this.computedMeta,
  computed:{
    computedMeta(){
      return [....] // an array of objects is stored in 'meta'
   }
  }
  methods:{
   yourMethod(sign){
     return this.$nuxt.$options.i18n.t(sign);
   }
  }
};

Simply import it as a mixin into the necessary file.

Encountering an error where the property '$options' is being attempted to be read from an undefined source while creating an external JavaScript

Answer №1

Answer №2

Similar questions

Reverting changes in three.js colors do not retroactively affect the instanceColor setting

Having trouble executing node commands in the terminal

Send input values to a JavaScript function from an onchange event

Facing an issue where WordPress AJAX is not showing the expected content

When incorporating babel-plugin-styled-components, Nextjs may encounter a mismatch error with classnames

Creating PropTypes from TypeScript

Suggestions on how to refactor redundant code in various peer AngularJS controllers for handling $intervals

When combining AJAX with PHP and HTML, one limitation to note is that PHP alone cannot generate or create the file

The SVG animation initiates without any manual intervention

Tips for updating iframe source without refreshing the iframe?

Utilizing `getElementById( x )` to assign `someFunction` to an onclick

Having trouble getting JavaScript to show a variable in an HTML document

The suggestions generated by the Google Books API do not align with what I was looking

The issue persists with the JavaScript window.location script constantly refreshing

Refreshing information on a custom component in a Bootstrap table using Vue

nested distinct apartment in js

Troubleshooting: Issue with jQuery not retrieving the value of input:nth-child(n)

Retrieve the ID from either a search query or an insertion operation in MongoDB

Creating a streamlined process for developing a library that is compatible with various languages and platforms

The AngularJS $resource is taking the entire object and embedding it into the URL