What Is ModelValue In Vue?

If you’re eager to expand your knowledge of Vue.js and want to gain a deeper understanding of its inner workings, you’ve come to the right place.

Today, we’ll explore the concept of modelValue and its significance in Vue.

Through clear explanations and practical examples, we’ll demystify this concept, empowering you to build more interactive and data-driven applications with ease.

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modelValue In Vue

modelValue In Vue is a special property that is often used as a way to establish two-way data binding between a parent component and its child component.

What Is modelValue In Vue?

What Is modelValue In Vue? In Vue, modelValue is a special property that is often used as a way to establish two-way data binding between a parent component and its child component.

It allows the parent component to pass data to the child component, and also enables the child component to emit changes back to the parent component.

The modelValue property serves as the intermediary value that holds the data being passed between the components.

By convention, the modelValue property is often used when creating custom form components or components that require user input.

It provides a consistent and convenient way to handle data synchronization between the parent and child components, making it easier to manage and update the state of the application.

modelValue Vue 3

modelValue Vue 3: The usage of modelValue remains the same as in previous versions.

However, there is a slight change in the syntax when defining the modelValue property within a component.

Instead of using the v-model directive to bind the modelValue property, Vue 3 introduces the v-bind and v-on directives in combination to achieve the same effect.

Here’s an example of how you can use modelValue in Vue 3:

In this example, we have a simple input component that receives the modelValue as a prop. The :value binding ensures that the input field is initially populated with the value of modelValue .

When the user types into the input field, the @input event is triggered, and we emit an event called ‘update:modelValue ‘ with the updated value.

This allows the parent component to receive the updated value and keep it in sync with the child component.

Update modelValue Vue 3

Update modelValue Vue 3: To update the modelValue in Vue 3, you can leverage the v-model directive and emit events.

The v-model directive is a shorthand for two-way data binding, allowing you to bind the modelValue to a component’s property and automatically update it when the value changes.

Let’s look at an example:

Computed modelValue Vue 3

Computed modelValue Vue 3: In addition to updating the modelValue using events, you can also utilize computed properties in Vue 3 to derive and update the modelValue based on other data properties.

Computed properties are reactive and automatically update whenever the dependencies they rely on change. Let’s see an example of how to use computed properties for the modelValue :

In this example, we have an input field where users can enter a value, and a computed property called modelValue .

The get function of the computed property returns the derived value of modelValue , which is based on the inputValue property in this case.

In this example, we convert the inputValue to uppercase.

Additionally, the set function allows us to update the inputValue whenever the modelValue is modified.

In this case, we convert the modified modelValue back to lowercase and assign it to the inputValue.

By utilizing computed properties, you can create a calculated modelValue that reacts to changes in other data properties, providing a convenient way to update the modelValue.

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Vue 3 Watch modelValue

Vue 3 Watch modelValue : You can use the watch option to observe changes specifically on the modelValue prop and perform additional actions or computations when it updates.

Here’s an example:

In this example, we have a component that receives the modelValue prop.

The watch option is used to define a watcher for the modelValue prop, which will trigger the associated callback whenever the prop’s value changes.

Inside the watcher, you can perform any actions or computations based on the updated value.

In the provided example, the watcher logs the new value and the previous value of modelValue to the console whenever it changes.

You can customize the logic within the watcher to suit your specific requirements, such as updating other properties or making API requests based on the new value.

Vue 3 Emit modelValue

Vue 3 Emit modelValue : In Vue 3, you can emit events to notify parent components about changes to the modelValue .

By emitting events, you enable communication between child and parent components and allow the parent component to react to changes in the child’s modelValue . Here’s an example:

In this example, we have a component with an input field bound to the modelValue data property using the v-model directive.

When the input value changes, it triggers the updatemodelValue method.

Within this method, we update the modelValue with the new value from the input field and emit an event called ‘update:modelValue ‘ with the updated value as the payload.

To use this component and receive the updated modelValue , you would include it in a parent component and listen to the ‘update:modelValue ‘ event.

Here’s an example of using the component:

In this parent component, we import and include the MyComponent component.

We listen to the ‘update:modelValue ‘ event using the @update:modelValue syntax and provide a corresponding method (handlemodelValue Update) that will be invoked when the event is emitted.

Inside this method, you can perform any actions or update other properties based on the received modelValue .

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Vue v-model Custom Component

Vue v-model custom component example

Vue v-model custom component example: The v-model directive in Vue.js allows for two-way data binding between a parent component and its child component.

It provides a convenient way to sync the state between the parent and child components, enabling easy communication and interaction.

In some cases, you may want to create custom components that utilize the v-model directive to enhance reusability and encapsulation.

To illustrate the usage of a Vue v-model custom component, let’s consider an example where we have a custom input component called CustomInput.

This component will be responsible for rendering an input field and handling the data binding using the v-model directive.

In the above example, the CustomInput component receives a value prop from its parent component, which represents the current value of the input field.

The :value binding ensures that the input field displays the correct value based on the prop.

The @input event listener is used to capture user input and emit an event called ‘input’ along with the new value.

By convention, Vue components that use v-model should emit an ‘input’ event to update the parent component’s data.

Now, let’s see how we can use the CustomInput component in a parent component:

In the parent component, we bind the inputValue data property to the v-model directive of the CustomInput component.

This enables two-way data binding, meaning that any changes made in the child component’s input field will automatically update the inputValue in the parent component, and vice versa.

As a result, whenever the user types something in the CustomInput component, the inputValue in the parent component will be updated, and its new value will be displayed below the input field.

Vue 3 Composition API v-model Custom Component

Vue 3 Composition API v-model Custom Component: In Vue 3, the Composition API provides a more flexible and powerful way to define components.

The v-model directive can also be used with custom components created using the Composition API, allowing you to leverage its benefits.

Let’s demonstrate the usage of Vue 3 Composition API with a v-model custom component example:

Vue 3 Composition API v-model Custom Component

In this Vue 3 example, we’re using the ref function from the Composition API to create a reactive variable called inputValue.

The ref function ensures that changes to this variable are reactive, meaning that any updates will trigger reactivity in the template where it is used.

The CustomInput component remains the same as in the Vue 2 example. It receives the value prop and emits an ‘input’ event when the input value changes.

By binding the inputValue to the v-model directive of the CustomInput component, we establish the two-way data binding.

Changes in the input field will update the inputValue variable, and updates to inputValue will reflect in the input field.

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Vue 2 v-model

Vue 2 v-model Custom Component

Vue 2 v-model Custom Component: In Vue.js, the v-model directive is a powerful feature that provides two-way data binding between form input elements and the underlying data.

It allows you to create interactive and dynamic user interfaces by automatically synchronizing the input values with the data properties in your Vue instance.

To illustrate this, let’s consider an example where we have a custom component called CustomInput.

This component accepts a value prop and emits an input event to update the value. Here’s how you can define the component:

In this example, the value prop represents the initial value of the input field, and the input event is emitted whenever the input value changes.

Now, you can use this CustomInput component with the v-model directive in a parent component:

By using v-model with the CustomInput component, the parent component establishes a two-way binding.

Any changes made to the input in the CustomInput component will be reflected in the customValue data property of the parent component, and vice versa.

Vue 2 v-model sync

Vue 2 v-model sync: In certain cases, you may need to synchronize the v-model directive with a property that has a different name than the default value property.

Vue 2 provides a modifier called .sync that allows you to achieve this.

To demonstrate the usage of .sync, consider an example where you have a parent component with a data property called message and a child component named ChildComponent.

The parent component wants to bind the message property to the v-model directive in the child component, but the child component expects a prop named content instead.

Here’s how you can accomplish this using the .sync modifier:

In this example, the parent component binds the message data property to the v-model.sync directive in the input element.

The .sync modifier ensures that changes made to the message property in the child component are also reflected in the parent component, and vice versa.

The child component, ChildComponent, expects a prop named content and binds it to the v-model.sync directive in its internal input element.

Therefore, any changes made to the input in the child component will be synchronized with the message data property in the parent component.

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Vue 2 v-model props

Vue 2 v-model props: In Vue 2, the v-model directive works by default with the value prop of form input elements.

However, you can customize the prop name used by v-model for data synchronization by using the model option in your component.

Let’s illustrate this with an example where you have a custom component called CustomCounter.

This component represents a counter with an internal value, and you want to use v-model to bind the value to a different prop name, such as countValue.

In this example, the model option is defined within the component definition.

It specifies that the countValue prop should be used for data synchronization with the v-model directive, and the corresponding event to be emitted is ‘count-change’.

Now, you can use the CustomCounter component with v-model in a parent component:

In this example, the v-model directive in the parent component binds the counterValue data property to the countValue prop in the CustomCounter component.

Any changes made to the counter value inside the CustomCounter component will be reflected in the counterValue data property of the parent component.

How Do You Find The v-model Value?

How Do You Find The v-model Value? To access the value bound with v-model, you can reference the corresponding data property in your Vue instance or component.

The v-model directive automatically syncs the input value with the specified property, so accessing the value is as simple as referencing the property.

For example, if you have an input element with v-model=”name”, you can access the current value of name by referencing this.name in the corresponding Vue instance or component.

Here, this refers to the current instance or component context.

If you’re working with nested components, the value will be accessible in the parent component as long as you have established the necessary v-model binding between the child and parent components.

What Is The Difference Between v-model And v-bind?

What Is The Difference Between v-model And v-bind? The v-model and v-bind directives in Vue.js serve different purposes and have distinct functionalities:

v-model: The v-model directive is a shorthand for creating two-way data binding between form input elements and data properties. It automatically syncs the input value with the underlying data, allowing changes in the input to be reflected in the data and vice versa.

v-bind: The v-bind directive, denoted by the colon (:) prefix, is used for one-way data binding. It allows you to bind the value of an attribute or a component prop to an expression or a data property. With v-bind, you can dynamically bind a value to an attribute, such as :class, :style, or any other attribute that requires data binding.

Hopefully, you now have a better understanding of how you can use modelValue in Vue.

Understanding how you can use modelValue in Vue is gonna help you to establish two-way data binding between a parent component and its child component.