Vuelidate: validate form with sub components

Question

How to work with validations of nested components inside a parent component with Vuelidate? I would like to change parentForm.$invalid if inputs in subcomponents are valid or not.

Parent:

<parent-component>
  </child-component-1>
  </child-component-2>
</parent-component>

validations: {
  parent: WHAT HERE?
}

Child-1

<child-component-1>
  </some-input>
</child-component-1>

data() {
  return {
    someInput: ""
  };
},

validations: {
  someInput: required
}

Child-2

<child-component-2>
  </some-input>
</child-component-2>

data() {
  return {
    someInput: ""
  };
},

validations: {
  someInput: required
}

Answer 1

The simplest way to get started with vuelidate for sub-components/form is to use Vue.js dependency injection mechanism provided by provide/inject pair. The $v instance created in parent component can be shared with children component.

As you more fine tune it, you can use Vuelidate data-nesting and only pass a subset of $v to your subcomponents. This is a roughly similar approach to how Angular does with nested Forms. It would look something like:

export default {
    data() {
        return {
            form1: {
                nestedA: '',
                nestedB: ''
            } /* Remaining fields */
        }
    },
    validations: {
        form1: {
            nestedA: {
                required
            },
            nestedB: {
                required
            }
        },

        form2: {
            nestedA: {
                required
            },
            nestedB: {
                required
            }
        }
    }
}

Alternately, you can declare independent instances of $v for each component. In your case, you will have one for parent and two for children. When you hit the submit button, get the reference of child component using $refs and check if nested form within the child component is valid or not.