Bind parent-scope attributes to a sub node in Vue

Overriding the default behaviour for spreading parent-scope attributes in Vue.js.

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If you work with Vue.js, you probably already created (or will) your own components within your application. By component, I mean a small piece of user interface such as a button, a text input or a carousel.

I recently struggled while I was working with a custom input component. The problem was that parent-scope attributes I was adding to the component were not bound to my input. Then I learned these two Vue features:

  • $attrs.
  • inheritAttrs.

Context

This is a simplified version of the component:

<template>
	<div class="InputComponent">
		<input v-model="model" type="text" />
	</div>
</template>

<script>
	export default {
		name: 'InputComponent',
		data() {
			return {
				model: ''
			};
		}
	};
</script>

Let’s say I want to import this component and add some attributes to it:

<input-component data-tracking="name" id="name"></input-component>

By doing this, if I inspect my HTML with the devtools, I can see that the input tag didn’t receive the id nor the data-tracking attributes. But the main wrapper of the component (.InputComponent) did.

Vue, $attrs and inheritAttrs

The above behavior is the default one: Vue creates an object with the attributes (only those not linked to a prop) and then spreads it to the root element of a component.

You can choose to remove this default behavior by adding the property inhertiAttrs: false to the component. Doing this will give you access to a new object with all parent-scope attributes: $attrs.

Then you can use the v-bind directive to spread this object on the desired element. Here is the updated input component:

<template>
	<div class="InputComponent">
		<input v-model="model" type="text" v-bind="$attrs" />
	</div>
</template>

<script>
	export default {
		name: 'InputComponent',
		inheritAttrs: false,
		data() {
			return {
				model: ''
			};
		}
	};
</script>

And here is the rendered component:

<div class="InputComponent">
	<input type="text" data-tracking="name" id="name" />
</div>

Wrapping up

  • Each component has an object containing all parent-scope attributes.
  • This object is spread on the root element by default.
  • You can choose to spread this object to another element with inheritAttrs, v-bind and $attrs.

That’s it. I love the flexibility Vue gives to developers. Even after almost 2 years working with this framework, I’m still learning this kind of cool features.