Child Component Validation Angular 5

Question

I need to validate the child component control after click parent component button click in angular6

Sample code dispaly below.

</form>

<--Parent Component-->

<div Class="row">

<div class="col-md-1">

<button type="submit" class="btn btn-primary btn-sm" style="margin-right:3px;" >Save</button>

</div>

<div class="col-md-1">

<button type="button" class="btn btn-primary btn-sm" style="margin-right:3px;" >Next</button>

</div>

</div>

<div class="row">

<--ChildComponent-->

<app-orderSubmit-details>

</app-orderSubmit-details>

</div>

<div class="row">

<--ChildComponent-->

<app-orderData-details>

</app-orderData-details>

</div>

<div class="row">

<--ChildComponent-->

<app-order-details>

</app-order-details>

</div>