Let's say the data from the App component needs to go to GrandChildComponent . In that case, you need to pass it through two intermediate components using props, even if those components don't need that data to function properly. That makes the code more cumbersome and harder to debug.
Vue handles this error with the provide/inject feature , which allows a parent component to provide data or functions to its child components without regard to the level of nesting. This solution simplifies data sharing and improves code organization.
A provider component aims to share data or processing methods with its child components. It uses the provide option to make this data available to the child component. Here is an example of a provider component:
This block of code shows a provider component, App , that provides a greeting variable to all of its children. To provide a variable, you need to set a key. Giving keys the same name as variables helps you maintain code.
Child components are elements within a nested structure. They can insert and use data provided in their component instances. Here's how it's done:
The child component inserts the provided data and can access it in the template as a locally defined variable:
Now observe the image below:
In this image, you can see a hierarchy consisting of four components, starting with the root component as the starting point. The other components nest within the hierarchy, ending with the GrandChild component .
The GrandChild component receives the data provided by the App. With this mechanism, you can avoid passing data through Parent and Child components , because those components do not need data to function properly.
You can provide app-level data with Vue's provide/inject. This is a common use case for sharing data and configuration across different components in a Vue app.
Examples of how you can provide application-level data:
// main.js import { createApp } from 'vue' import App from './App.vue' const globalConfig = { apiUrl: 'https://example.com/api', authKey: 'my-secret-key', // Other configuration settings. }; app.provide('globalConfig', globalConfig); createApp(App).mount('#app')
Suppose you have an application that needs a global configuration object containing API endpoints, user authentication information, and other settings.
You can achieve this by providing configuration data in the top-level component, typically in the main.js file, allowing other components to insert and use it:
API URL: {{ globalConfig.apiUrl }}
Authentication Key: {{ globalConfig.authKey }}
The above component uses the inject function to access the globalConfig object , which the app provides at the global level. You can access any properties or settings from globalConfig by interpolating or binding these properties with other project binding techniques in Vue.
Although they bring many benefits, you should use the above two ingredients carefully to avoid unwanted side effects.