What are custom directives?

Custom Directives are tiny commands that you can attach to DOM elements. They are prefixed with v- to let the library know you're using a special bit of markup and to keep syntax consistent. They are typically useful if you need low-level access to an HTML element to control a bit of behavior.

Let's create a custom focus directive to provide focus on specific form element during page load time,

// Register a global custom directive called `v-focus`
Vue.directive('focus', {
// When the bound element is inserted into the DOM...
inserted: function (el) {
// Focus the element
el.focus()
}
})

Now you can use v-focus directive on any element as below,

<input v-focus>