Vue.js 3.0 Tutorial
Vue.js 3.0 Component Advanced
Vue.js 3.0 Transitions & Animations
Vue.js 3.0 Reusable & Combinable
Vue.js 3.0 Advanced
Vue.js 3.0 Tools
Vue.js 3.0 Scale
Vue.js 3.0 Accessibility
Vue.js 3.0 Migrating from Vue2
Vue.js 3.0 Contribute Documentation
Vue.js 3.0 API References
Vue.js 3.0 Style Guide
In Vue 3.0, the render function has become more prevalent due to the Composition API, which allows for better code organization, especially in large projects.
The render function is a more flexible alternative to templates, giving you full programmatic control over the Vue instance's output. It's important to remember that the render function receives a createElement function as its argument, often abbreviated as h.
Here is a basic usage of a render function:
const app = Vue.createApp({
render(h) {
return h('div', 'Hello from render function!')
}
}).mount('#app');
In this code, h function is creating a new div with the text 'Hello from render function!'.
h function accepts three arguments:
Let's use a more complex example:
const app = Vue.createApp({
data() {
return {
message: 'Hello from Vue!'
};
},
render(h) {
return h('div', [
h('h1', 'Render Function'),
h('p', this.message)
]);
}
}).mount('#app');
In this example, we're creating a div with two children - an h1 tag and a p tag. The p tag contains a reactive message from our data property.
You can also use render functions to conditionally render components, manipulate children elements programmatically, access component's slots, or even render components dynamically.
const app = Vue.createApp({
data() {
return {
shouldShow: true
}
},
components: {
'my-component': {
render(h) {
return h('p', 'I am a component')
}
}
},
render(h) {
let children = this.shouldShow ? [h('my-component')] : [];
return h('div', children);
}
}).mount('#app');
In this example, a custom component my-component is conditionally rendered based on the shouldShow data property.
Remember, Vue's render function can be very powerful, but it also comes with complexity. It is recommended to use Vue's template syntax for most cases and only use render functions when absolutely necessary.
Vue 3.0 Render Function vs. Template:
In Vue 3.0, you can use either templates or render functions to define your components.
Templates provide a more declarative and concise syntax, while render functions offer more flexibility and control.
Example code:
<!-- TemplateComponent.vue -->
<template>
<div>{{ message }}</div>
</template>
<script>
export default {
data() {
return {
message: 'Hello from template!',
};
},
};
</script>
<!-- RenderComponent.vue -->
<script>
export default {
render() {
return this.$createElement('div', this.message);
},
data() {
return {
message: 'Hello from render function!',
};
},
};
</script>
Dynamic Rendering in Vue 3.0:
Dynamic rendering involves conditionally rendering content based on data.
It can be achieved using both templates and render functions.
Example code:
<!-- DynamicRendering.vue -->
<template>
<div>
<p v-if="isVisible">This is visible</p>
<p v-else>This is hidden</p>
</div>
</template>
<script>
export default {
data() {
return {
isVisible: true,
};
},
};
</script>
Render Functions and JSX in Vue 3.0:
Render functions can be written using JSX (JavaScript XML) syntax for a more concise representation.
JSX offers a syntax similar to HTML, making it easier to read and write.
Example code:
<!-- JSXRendering.vue -->
<script>
export default {
render() {
return <div>{this.message}</div>;
},
data() {
return {
message: 'Hello from JSX!',
};
},
};
</script>
Vue 3.0 h() Function in Render:
The h() function is a shorthand for this.$createElement in render functions.
It is commonly used to create virtual DOM nodes.
Example code:
<!-- HFunctionRendering.vue -->
<script>
export default {
render() {
return this.h('div', this.message);
},
data() {
return {
message: 'Hello from h() function!',
};
},
};
</script>
Composing Components with Render Function in Vue 3.0:
Render functions can be used to compose components dynamically, allowing for more complex UI structures.
Child components can be created and rendered within the parent's render function.
Example code:
<!-- ComposeComponents.vue -->
<script>
import ChildComponent from './ChildComponent.vue';
export default {
render() {
return this.h('div', [
this.h('p', 'Parent component content'),
this.h(ChildComponent),
]);
},
};
</script>
<!-- ChildComponent.vue -->
<script>
export default {
render() {
return this.h('p', 'Child component content');
},
};
</script>
Vue 3.0 Functional Components and Render:
Functional components in Vue 3.0 are stateless and don't have an instance, making them ideal for render functions.
They receive props as parameters and return virtual DOM nodes.
Example code:
<!-- FunctionalComponent.vue -->
<script>
export default {
functional: true,
render(h, context) {
return h('div', `Hello, ${context.props.name}!`);
},
props: {
name: String,
},
};
</script>
Scoped Slots and Render Functions in Vue 3.0:
Render functions allow for more dynamic usage of scoped slots, providing flexibility in defining slot content.
Scoped slots can be utilized within the render function for dynamic content injection.
Example code:
<!-- ScopedSlotsRendering.vue -->
<script>
export default {
render() {
return this.h('div', [
this.$scopedSlots.default({ message: 'Hello from scoped slot!' }),
]);
},
};
</script>
Vue 3.0 Render Function and Reactivity:
Render functions are reactive, meaning they automatically update when the underlying data changes.
Changes to reactive data trigger a re-render of the component.
Example code:
<!-- ReactivityRendering.vue -->
<script>
export default {
render() {
return this.h('div', this.message);
},
data() {
return {
message: 'Initial message',
};
},
mounted() {
setTimeout(() => {
this.message = 'Updated message';
}, 2000);
},
};
</script>
Vue 3.0 Render Function Examples:
Various examples of using render functions for different scenarios, including conditional rendering and dynamic content.
Example code:
<!-- RenderFunctionExamples.vue -->
<script>
export default {
render() {
if (this.condition) {
return this.h('p', 'Condition is true');
} else {
return this.h('p', 'Condition is false');
}
},
data() {
return {
condition: true,
};
},
};
</script>