Home Web Front-end Vue.js Using custom instructions to implement special functions in Vue

Using custom instructions to implement special functions in Vue

Oct 15, 2023 am 08:38 AM
vue Custom instructions special function

Using custom instructions to implement special functions in Vue

Use custom instructions in Vue to implement special functions

Introduction:
Vue is a very powerful JavaScript framework that provides us with A convenient and efficient way to build interactive web applications. In addition to the built-in directives (such as v-model, v-if, etc.), Vue also allows us to create custom directives to extend its functionality.

This article will introduce how to use custom instructions in Vue to implement some special functions, and provide corresponding code examples for reference.

1. Custom global directives
Global directives can be used in any Vue component. The following is an example that demonstrates how to create a global directive to set the focus of the input box:

Vue.directive('focus', {
  inserted: function (el) {
    el.focus();
  }
});
Copy after login

The above code creates a directive named "focus" and defines its inserted hook function, which will be called when the bound element is inserted into the DOM. In this example, we automatically set focus on the bound element (i.e. input element) when it is inserted into the DOM.

Using global directives in Vue components is very simple, just add the v-focus directive on the corresponding element:

<input v-focus>
Copy after login

In this way, no matter which Vue component uses v-focus Instructions and their corresponding input boxes will automatically gain focus.

2. Custom local directives
In addition to global directives, Vue also allows us to create local directives, which means that specified directives are only available in specific Vue components. The following is an example that demonstrates how to create a local directive to limit the input box to only numbers:

Vue.component('custom-input', {
  template: `<input v-only-number>`,
  directives: {
    'only-number': {
      bind: function (el) {
        el.addEventListener('input', function (e) {
          if (!/^d*$/.test(e.target.value)) {
            e.target.value = e.target.value.replace(/[^d]/g, '');
          }
        });
      }
    }
  }
});
Copy after login

The above code creates a local directive named "only-number" and places it in the Vue component Used in "custom-input". This instruction binds the input event of the input box element, and when the event is triggered, it uses a regular expression to determine whether the input value is a number, and if not, replaces the non-numeric characters with an empty string.

In the Vue component that uses this custom directive, just use it as follows:

<custom-input></custom-input>
Copy after login

In this way, the corresponding input box can only enter numbers, and any non-numeric characters will is automatically deleted.

3. Hook functions of custom instructions
In addition to inserted and bind, Vue also provides some other hook functions to control the behavior of custom instructions in the life cycle of the component. Here are some commonly used hook functions:

  • bind: Called when the directive is bound to the element, only called once.
  • inserted: Called when the bound element is inserted into the DOM.
  • update: Called when the component's VNode is updated, but may be called before the child component's VNode is updated.
  • componentUpdated: Called after the component's VNode and the VNode of its subcomponents are updated.
  • unbind: Called when the instruction is unbound from the element.

Summary:
Through custom instructions, we can easily extend the functions of Vue to meet some special needs. This article explains how to create global and local directives and provides corresponding code examples. In addition, Vue also provides a wealth of hook functions, which can provide fine control over custom instructions at different life cycle stages.

I hope this article can help you understand the use of custom instructions in Vue, and inspire you to apply them in actual projects. If there are any shortcomings, please correct me, thank you!

The above is the detailed content of Using custom instructions to implement special functions in Vue. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to use bootstrap in vue How to use bootstrap in vue Apr 07, 2025 pm 11:33 PM

Using Bootstrap in Vue.js is divided into five steps: Install Bootstrap. Import Bootstrap in main.js. Use the Bootstrap component directly in the template. Optional: Custom style. Optional: Use plug-ins.

How to add functions to buttons for vue How to add functions to buttons for vue Apr 08, 2025 am 08:51 AM

You can add a function to the Vue button by binding the button in the HTML template to a method. Define the method and write function logic in the Vue instance.

How to use watch in vue How to use watch in vue Apr 07, 2025 pm 11:36 PM

The watch option in Vue.js allows developers to listen for changes in specific data. When the data changes, watch triggers a callback function to perform update views or other tasks. Its configuration options include immediate, which specifies whether to execute a callback immediately, and deep, which specifies whether to recursively listen to changes to objects or arrays.

What does vue multi-page development mean? What does vue multi-page development mean? Apr 07, 2025 pm 11:57 PM

Vue multi-page development is a way to build applications using the Vue.js framework, where the application is divided into separate pages: Code Maintenance: Splitting the application into multiple pages can make the code easier to manage and maintain. Modularity: Each page can be used as a separate module for easy reuse and replacement. Simple routing: Navigation between pages can be managed through simple routing configuration. SEO Optimization: Each page has its own URL, which helps SEO.

How to reference js file with vue.js How to reference js file with vue.js Apr 07, 2025 pm 11:27 PM

There are three ways to refer to JS files in Vue.js: directly specify the path using the &lt;script&gt; tag;; dynamic import using the mounted() lifecycle hook; and importing through the Vuex state management library.

How to return to previous page by vue How to return to previous page by vue Apr 07, 2025 pm 11:30 PM

Vue.js has four methods to return to the previous page: $router.go(-1)$router.back() uses &lt;router-link to=&quot;/&quot; component window.history.back(), and the method selection depends on the scene.

How to use vue traversal How to use vue traversal Apr 07, 2025 pm 11:48 PM

There are three common methods for Vue.js to traverse arrays and objects: the v-for directive is used to traverse each element and render templates; the v-bind directive can be used with v-for to dynamically set attribute values ​​for each element; and the .map method can convert array elements into new arrays.

How to jump to the div of vue How to jump to the div of vue Apr 08, 2025 am 09:18 AM

There are two ways to jump div elements in Vue: use Vue Router and add router-link component. Add the @click event listener and call this.$router.push() method to jump.

See all articles