form.vue

<template>
  <form id="registerForm" method="POST" @submit.prevent="validateBeforeSubmit">
    <fieldset>
        <legend>Mi formulario con Vuejs 2</legend>
        <div class="form-group col-xs-3 col-md-2">
            <label for="firstname" class="control-label">Nombre</label>
            <input
                v-model="firstname"
                name="firstname"
                class="form-control"
                id="firstname"
                placeholder="Nombre"
                v-validate="'required'"
                :class="{'has-errors': errors.has('firstname')}"
            >
            <FormError :attribute_name="'firstname'" :errors_form="errors"> </FormError>
        </div>
        
        <!-- componente anidado -->
        <my-date-component></my-date-component>
        
    </fieldset>
  </form>
</template>

<script>
    import FormError from '../FormError';
    import MyDateComponent from '../MyDateComponent';
    export default {
        name: "form-component",
        components: { FormError, MyDateComponent }
    }
</script>