Vue.js is a lightweight MVVM front-end framework that can easily manage complex front-end applications. In the process of using Vue.js, in addition to interacting with the back-end data interface, we also need to process static data, such as some default values, constants, configurations, etc. in the page. This article will introduce how to use static data in Vue.js.
1. Define static data in Vue.js
To define static data, you can use the data option provided in Vue.js, which can be a function or an object.
(1) Function mode:
new Vue({ data: function () { return { message: 'Hello Vue.js!' } } })
(2) Object mode:
new Vue({ data: { message: 'Hello Vue.js!' } })
To define static data in a component, you need to use a function, that is, the component needs to return a new object. Since components can be reused, they cannot be defined directly using objects, otherwise errors will occur.
Vue.component('my-component', { data: function () { return { message: 'Hello Vue.js!' } }, template: '<div>{{ message }}</div>' })
In this example, we define a component and we need to return an object containing the message attribute.
2. Using static data in Vue.js
To use static data in Vue.js, we need to interpolate or bind expressions in the template.
(1) Interpolation
Interpolation is a way to insert data into the DOM tree. Use {{ }} to insert Vue.js data. Below is an example using interpolation.
<div id="app"> <p>{{ message }}</p> </div>
new Vue({ el: '#app', data: { message: 'Hello Vue.js!' } })
In this example, we use Vue.js's data message to insert into the
element.
(2) Binding attributes
In addition to using interpolation to render data, you can also use the v-bind directive to bind one of the element attributes. Here is an example of using v-bind:
<div id="app"> <img v-bind:src="imageSrc"> </div>
new Vue({ el: '#app', data: { imageSrc: 'https://vuejs.org/images/logo.png' } })
In this example, we bind the src attribute of the element to the Vue.js data imageSrc.
(3) Using filters
When we need to perform certain processing on static data, we can use the filter provided by Vue.js to process it. Below is an example of using filters.
<div id="app"> <p>{{ message | capitalize }}</p> </div>
Vue.filter('capitalize', function (value) { if (!value) return '' value = value.toString() return value.charAt(0).toUpperCase() + value.slice(1) }) new Vue({ el: '#app', data: { message: 'hello vue.js!' } })
In this example, we define a filter capitalize that capitalizes the first letter of a string. The usage in the template is to follow the message with a pipe character (|) and the name of the filter.
3. Vue.js dynamically updates static data
When we need to dynamically update static data, we only need to modify the bound data through the instance method of Vue.js.
<div id="app"> <input v-model="message" type="text"> <p>{{ message }}</p> </div>
new Vue({ el: '#app', data: { message: 'Hello Vue.js!' } })
In this example, we bind an input element and use the v-model directive to bind it to the data message of the Vue.js instance. When data changes, Vue.js will automatically update the DOM.
4. Summary
Through the study of this article, we have learned how to define and use static data in Vue.js. At the same time, we also learned how to use Vue.js instance methods to dynamically update static data. In actual development, we need to flexibly use the above techniques to better realize our development needs.
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