Exploring the way to reference 'this' within props validation

Question

Exploring the way to reference 'this' within props validation

Currently, I am engaged in a project using nuxt.js where I am implementing a function into the application context as advised by the official documentation.

https://nuxtjs.org/guide/plugins/#inject-in-root-amp-context

However, I encountered an issue when trying to invoke the function within a props validation process.

/plugins/check-props.js

import Vue from 'vue'

Vue.prototype.$checkProps = function(value, arr) {
  return arr.indexOf(value) !== -1
}

This is happening within a Vue component:

export default {
  props: {
    color: {
      type: String,
      validator: function (value, context) {
        this.$checkProps(value, ['success', 'danger'])
      }
  }
}

ERROR: Cannot read property '$checkProps' of undefined

I am seeking guidance on how to access "this" within the validation process.

Your help will be much appreciated. Thank you!

javascript vue.js nuxt.js

Answer 1

Answer №1

Validation of props occurs prior to the initialization of the component, which means that accessing this while extending Vue.prototype is not possible.

According to their official documentation:

Keep in mind that props are checked before a component instance is generated, so properties like data and computed will not be accessible within default or validator functions.

If you only need to verify the values of these props using $checkProps, it might be more efficient to utilize a helper function instead.

// array.helpers.js
export function containsValue(arr, val) {
  return arr.indexOf(value) !== -1
}

// component
import { containsValue } from 'path/to/helpers/array.helpers';
props: {
    foo: {
       //
       validator(value) {
          return containsValue(['foo', 'bar'], value);
       }
    }
}

Update

In response to your feedback, if you wish to avoid importing the same function repeatedly, consider utilizing Array.prototype.includes as an alternative. You can consult the documentation for more information.

// component
props: {
    color: {
       //
       validator(value) {
          return ['success', 'danger'].includes(value);
       }
    }
}

Answer 2

Validation of props occurs prior to the initialization of the component, which means that accessing this while extending Vue.prototype is not possible.

According to their official documentation:

Keep in mind that props are checked before a component instance is generated, so properties like data and computed will not be accessible within default or validator functions.

If you only need to verify the values of these props using $checkProps, it might be more efficient to utilize a helper function instead.

// array.helpers.js
export function containsValue(arr, val) {
  return arr.indexOf(value) !== -1
}

// component
import { containsValue } from 'path/to/helpers/array.helpers';
props: {
    foo: {
       //
       validator(value) {
          return containsValue(['foo', 'bar'], value);
       }
    }
}

Update

In response to your feedback, if you wish to avoid importing the same function repeatedly, consider utilizing Array.prototype.includes as an alternative. You can consult the documentation for more information.

// component
props: {
    color: {
       //
       validator(value) {
          return ['success', 'danger'].includes(value);
       }
    }
}

Answer 3

Answer №2

According to the information provided on the documentation:

Prior to the creation of a component instance, props undergo validation which means that instance properties such as data, computed, etc will not be accessible within default or validator functions.

Answer 4

According to the information provided on the documentation:

Prior to the creation of a component instance, props undergo validation which means that instance properties such as data, computed, etc will not be accessible within default or validator functions.

Answer 5

Answer №3

To gain access to the nuxt plugins, you can utilize the window object. This is my method for accessing the i18n library:


{
   validator: (value: any): boolean => {
      return window.$nuxt.$te(value);
   }
}

In your specific scenario:


{
   validator: (value: any): boolean => {
      return window.$nuxt.$checkProps(value, ['success', 'danger']);
   }
}

It's essential not to prototype in the window object. Instead, let the nuxt manage it with a plugin:

Path: plugins/check-props.js or .ts


function checkProps(value: any, arr: string[]): boolean {
  return arr.indexOf(value) !== -1
}

const $checkProps: Plugin = (_context: Context, inject: Inject) => {
  inject('checkProps', checkProps);
};

export default $checkProps;

Then, include it in the nuxt config:


{
  plugins: [{ src: 'plugins/check-props.js', ssr: true }]
}

Answer 6

To gain access to the nuxt plugins, you can utilize the window object. This is my method for accessing the i18n library:


{
   validator: (value: any): boolean => {
      return window.$nuxt.$te(value);
   }
}

In your specific scenario:


{
   validator: (value: any): boolean => {
      return window.$nuxt.$checkProps(value, ['success', 'danger']);
   }
}

It's essential not to prototype in the window object. Instead, let the nuxt manage it with a plugin:

Path: plugins/check-props.js or .ts


function checkProps(value: any, arr: string[]): boolean {
  return arr.indexOf(value) !== -1
}

const $checkProps: Plugin = (_context: Context, inject: Inject) => {
  inject('checkProps', checkProps);
};

export default $checkProps;

Then, include it in the nuxt config:


{
  plugins: [{ src: 'plugins/check-props.js', ssr: true }]
}

Exploring the way to reference 'this' within props validation

Answer №1

Update

Answer №2

Answer №3

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