1. Introduction
In Vue 3's responsive system, toRefs and toRef are two practical tool functions that play an important role in processing responsive data. Using these two functions reasonably can make us more flexible when manipulating responsive objects and arrays, avoiding some potential data update problems. This article will explore in-depth the functions, usage scenarios and the differences between toRefs and toRef.
2. toRefs function
2.1 Basic Concept
The toRefs function is used to convert a responsive object into a normal object, each property of this normal object is a ref object, and these ref objects maintain a reference to the original responsive object properties. In other words, modifying the attribute value of the toRefs return object will simultaneously update the corresponding attribute value of the original responsive object; conversely, modifying the attribute value of the original responsive object will also update the corresponding attribute value of the toRefs return object.
2.2 Use examples
<template>
<div>
<p>The name of the original object: {{ }}</p>
<p>toRefs object's name: {{ }}</p>
<button @click="changeName">Modify name</button>
</div>
</template>
<script setup>
import { reactive, toRefs } from 'vue';
// Create a responsive object
const state = reactive({
name: 'John',
age: 30
});
// Use toRefs to convert responsive objects into normal objects, each property is a ref object
const toRefsState = toRefs(state);
const changeName = () => {
// Modify the property value of the toRefs object
= 'Jane';
};
</script>
In the above example, we first create a responsive object state and then convert it to toRefsState using the toRefs function. When we click the button to modify, the value of , will also be updated synchronously.
2.3 Use scenarios
Deconstructing responsive objects: In a component, when we need to deconstruct a responsive object and use its properties in a template, if we deconstruct directly, the responsive characteristics will be lost. Using toRefs can solve this problem, ensuring that the deconstructed properties remain responsive.
<template>
<div>
<p>{{ name }}</p>
<p>{{ age }}</p>
</div>
</template>
<script setup>
import { reactive, toRefs } from 'vue';
const state = reactive({
name: 'John',
age: 30
});
// Use toRefs to deconstruct responsive objects
const { name, age } = toRefs(state);
</script>
Passing properties of responsive objects to child components: When you need to pass properties of responsive objects to child components, using toRefs ensures that the properties received by the child component are responsive and that modifications to these properties by the child component are synchronized to the parent component.
3. toRef function
3.1 Basic Concept
The toRef function is used to create a ref object for a property of a responsive object. This ref object maintains a reference to the properties of the original responsive object. Modifying the value of the ref object will update the corresponding property value of the original responsive object, and vice versa. Unlike toRefs, toRef creates ref objects only for a single property.
3.2 Use examples
<template>
<div>
<p>The name of the original object: {{ }}</p>
<p>toRef object's name: {{ }}</p>
<button @click="changeName">Modify name</button>
</div>
</template>
<script setup>
import { reactive, toRef } from 'vue';
// Create a responsive object
const state = reactive({
name: 'John',
age: 30
});
// Create a ref object for using toRef
const nameRef = toRef(state, 'name');
const changeName = () => {
// Modify the value of the toRef object
= 'Jane';
};
</script>
In this example, we use the toRef function to create a ref object nameRef for . When we click the button to modify, the value of , will be updated accordingly.
3.3 Use scenarios
Create references to specific properties: Using toRef is very convenient when you only need to create a ref object for a specific property of a responsive object. For example, in some complex business logic, only a certain property of the object needs to be responsively operated.
Handling optional attributes: When a property of a responsive object may not exist, using toRef can safely create a reference to the attribute, even if the attribute does not exist, there will be no error.
4. The difference between toRefs and toRef
4.1 Scope of action
toRefs acts on the entire responsive object, converting all properties of the object into a ref object.
toRef acts only on a single property of a responsive object, creating a ref object for the specified property.
4.2 Return value
toRefs Returns a normal object whose properties are ref objects.
toRef Returns a separate ref object.
4.3 Flexibility
toRefs is suitable for scenarios where the properties of the entire responsive object need to be converted into ref objects, and the operation is relatively simple.
toRef is more flexible and can operate on specific attributes, suitable for handling complex business needs.
Conclusion
toRefs and toRef are very practical tool functions in Vue 3 responsive systems. toRefs is used to convert the properties of the entire responsive object into a ref object, which is convenient for deconstructing and passing responsive properties; toRef is used to create ref objects for a single property, providing finer-grained responsive operations. In actual development, developers should reasonably choose to use toRefs or toRef according to their specific business needs to fully utilize the advantages of Vue 3 responsive system.
Hope this article helps you better understand the use of toRefs and toRef in Vue 3. If you have any questions or experience sharing during use, please leave a message in the comment area for communication. Don’t forget to like and follow to get more practical tips for Vue 3 development!