28 December, 2020

Vue.js Component

                No comments   

Vue.js Component

Vue.js components are one of Vue.js' most important features and used to create custom elements that can be reused in HTML. Components are the reusable Vue.js instances with a name. We can use a component as a custom element inside a root Vue.js instance.

Following is the syntax to create a component.

Syntax:

  1. Vue.component('nameofthecomponent',{ // options});  

Let's create a component to understand it better how components work with Vue.js. See the following example:

Index.html file:

  1. <html>  
  2.    <head>  
  3.       <title>Vue.js Component</title>  
  4.       <link rel="stylesheet" href="index.css">  
  5.         <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>  
  6.     </head>  
  7.     <body>  
  8.       <div id = "component_test1">  
  9.          <testcomponent></testcomponent>  
  10.       </div>  
  11.       <div id = "component_test2">  
  12.          <testcomponent></testcomponent>  
  13.       </div>  
  14.       <script src="index.js"></script>  
  15.    </body>  
  16. </html>  

Index.js file:

  1. Vue.component('testcomponent',{  
  2.    template : '<div><h1>This is a component example</h1></div>'  
  3. });  
  4. var vm = new Vue({  
  5.    el: '#component_test1'  
  6. });  
  7. var vm1 = new Vue({  
  8.    el: '#component_test2'  
  9. });  

Let's use a simple CSS file to make the output more attractive.

Index.css file:

  1. html, body {  
  2.     margin: 5px;  
  3.     padding: 0;  
  4. }  

After the execution of the program, you will see the following output:

Output:

This is a component example
This is a component example
Vue.js Component

Example Explanation

In the above example, we have created two div with id component_test1 and component_test2 in the Index.html file. Once a component is created, the name of the component becomes the custom element and we can use this custom element in the Vue instance element created, i.e. inside the div with ids component_test1 and component_test2. Here, we have used a test component as the name of the component and the same name is used as the custom element inside the divs.

  1. <div id = "component_test1">  
  2.    <testcomponent></testcomponent>  
  3. </div>  
  4. <div id = "component_test2">  
  5.    <testcomponent></testcomponent>  
  6. </div>  

In the Index .js file, we have created two Vue.js instances with the respective div ids.

  1. var vm = new Vue({  
  2.    el: '#component_test1'  
  3. });  
  4. var vm1 = new Vue({  
  5.    el: '#component_test2'  

We have created a common component to use with both the view instances.

  1. Vue.component('testcomponent',{  
  2.    template : '<div><h1>This is a component example</h1></div>'   

Local registration of Components

We can directly make the components a part of vue.js instance by using the following code in Index.js file. This method is called local registration. Here, the components will be a part of only the created vue instance.

  1. var vm = new Vue({  
  2.    el: '#component_test1',  
  3.    components:{  
  4.       'testcomponent': {  
  5.         template : '<div><h1>This is a component example</h1></div>'   
  6.       }  
  7.    }  
  8. });  

After the execution of the program, you will see the following output:

Output:

Vue.js Component

Vue.js components with more options

We can add some more options such as data and methods to Vue.js components. It is same as we have added data and methods to Vue.js instance. See the following example:

Index.html file:

  1. <html>  
  2.    <head>  
  3.       <title>Vue.js Component</title>  
  4.       <link rel="stylesheet" href="index.css">  
  5.         <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>  
  6.     </head>  
  7.     <body>  
  8.       <div id = "component_test1">  
  9.          <testcomponent></testcomponent>  
  10.       </div>  
  11.       <div id = "component_test2">  
  12.          <testcomponent></testcomponent>  
  13.       </div>  
  14.       <script src="index.js"></script>  
  15.    </body>  
  16. </html>  

Index.js file:

  1. Vue.component('testcomponent',{  
  2.    template : '<div v-on:mouseover = "changename()" v-on:mouseout = "originalname();"><h1>This Custom Component is created by <span id = "name">{{name}}</span></h1></div>',  
  3.    data: function() {  
  4.       return {  
  5.          name : "Panda"  
  6.       }  
  7.    },  
  8.    methods:{  
  9.       changename : function() {  
  10.          this.name = "Alex";  
  11.       },  
  12.       originalname: function() {  
  13.          this.name = "Panda";  
  14.       }  
  15.    }  
  16. });  
  17. var vm = new Vue({  
  18.    el: '#component_test1'  
  19. });  
  20. var vm1 = new Vue({  
  21.    el: '#component_test2'  
  22. });  

In the above Index.js file, we have added a data in the form of a function that returns an object. The object has a name property, which has assigned the value 'Panda'. See the following template used in the example.

  1. template : '<div v-on:mouseover = "changename()" v-on:mouseout = "originalname();"><h1>This Custom Component is created by <span id = "name">{{name}}</span></h1></div>',  
  2.    data: function() {  
  3.       return {  
  4.          name : "Panda"  
  5.       }  

Here, we are using data as a function in components and we also use its properties the same way as we use with direct Vue instance. Here, we have used two methods, changename and originalname. In changename, we are changing the name property, and in originalname we are resetting it back to the original name.

We have also added two events on the div, mouseover and mouseout. Here, mouseover event is used to call changename method and mouseout event is used to call originalname method.

Now, execute the above program to see the output. After the execution of the program, you will see the following output:

Output:

Vue.js Component

You can see that the output displays the assigned name "Panda" which we have set in the data property in the Index.js file. We have also assigned a mouseover and a mouseout event on the div. So on mouseover, you will see that the name of the components are changed to Alex, and when mouseout, it will remain the same as Panda.

Vue.js Component

Vue.js Dynamic Components

Dynamic component means, a component which location in the application is not defined at buildtime. We don't define it in any Vue.js template. Instead of this, the dynamic component is instantiated and placed in the application at runtime. In Vue.js, a dynamic component is created using the keyword <component></component> and it is bound using a property. Let's take an example to understand it clearly.

Index.html file:

  1. <html>  
  2.    <head>  
  3.       <title>Vue.js Component</title>  
  4.       <link rel="stylesheet" href="index.css">  
  5.         <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>  
  6.     </head>  
  7.     <body>  
  8.       <div id = "databinding">  
  9.          <component v-bind:is = "view"></component>  
  10.       </div>  
  11.       <script type = "text/javascript">  
  12.          var vm = new Vue({  
  13.             el: '#databinding',  
  14.             data: {  
  15.                view: 'component1'  
  16.             },  
  17.             components: {  
  18.                'component1': {  
  19.                  template: '<div><span style = "font-size:25;color:Blue;">This is a Dynamic Component Example</span></div>'  
  20.                }  
  21.             }  
  22.          });  
  23.       </script>  
  24.       <script src="index.js"></script>  
  25.    </body>  
  26. </html>  

Index.js file:

  1. var vm = new Vue({  
  2.    el: '#databinding',  
  3.    data: {  
  4.       view: 'component1'  
  5.    },  
  6.    components: {  
  7.       'component1': {  
  8.          template: '<div><span style = "font-size:25;color:Blue;">This is a Dynamic Component Example</span></div>'  
  9.       }  
  10.    }  
  11. });  

Let's use a simple CSS file to make the output more attractive.

Index.css file:

  1. html, body {  
  2.     margin: 5px;  
  3.     padding: 0;  
  4. }  

After the execution of the program, you will see the following output:

Output:

This is a Dynamic Component Example

Vue.js Component

Example explanation

In the above example, you can see that the Dynamic component is created by using the following syntax.

  1. <component v-bind:is = "view"></component>  

Here, it has v-bind:is = "view", and a value view is assigned to it. View is defined in the Vue instance as follows.

  1. var vm = new Vue({  
  2.    el: '#databinding',  
  3.    data: {  
  4.       view: 'component1'  
  5.    },  
  6.    components: {  
  7.       'component1': {  
  8.          template: '<div><span style = "font-size:25;color:red;">Dynamic Component</span></div>'  
  9.       }  
  10.    }  
  11. });  

After the execution, you can see that the template displays that "This is a Dynamic Component Example" in the browser.

By Source : javatoint

Related Posts:

  • Vue.js Computed PropertiesVue.js Computed Properties In Vue.js, computed properties are used when we have to handle complex logic and operations. Computed properties are j… Read More
  • Vue.js Event HandlingVue.js Events In Vue.js, Events are used to respond to an action. Suppose, you have to build a dynamic website using Vue.js then you'll most like… Read More
  • Vue.js Watch PropertyVue.js Watch PropertyThe Vue.js Watcher or watch property allows the developers to listen to the component data and run whenever they change a particu… Read More
  • Vue.js Data BindingVue.js Data BindingVue.js supports different types of data binding. Before going to learn data binding in Vue.js, let's see what data binding is and h… Read More
  • Vue.js Form Input BindingsVue.js Form Input BindingsVue.js provides a v-model directive that can be used to create two-way data bindings on form inputs, text, textare… Read More

0 comments:

Post a Comment

Thanks

Meta

Popular Posts

Categories

Social Media Links

Blog Archive