title: Trigger a function from father component - that will run componentDidMount at child's component
body: <p>so i got this React project - there is an admin page and i can add new vacations (with Reactstrap Modal).
  the Vacations are added to the database and are shwon in a child's component called AdminVacations.
  the array of the Vacations is loaded at the child's component.
  this is the code to add Vacation (in admin component)</p>
  
  <pre><code> async Add (){
          let NewVac = {
          name:this.state.name,
          price:this.state.price,
          start:this.state.start,
          end:this.state.end,
          image:this.state.file,
          description:this.state.description
          }
  
          let r = await fetch(`${apiUrl}/addvacation`, {
              method: 'POST',
              headers: {
                'Accept': 'application/json',
                'Content-Type': 'application/json'
              },
              body: JSON.stringify(NewVac)
            });
          let jsonData= await r.json(); 
          if (r.status === 200){
              this.toggle();
  
          }
  
      }
  </code></pre>
  
  <p>i also got edit and delete buttons - which found in the child's child component.
  the problem is that i need to show the changes on the screen(Live).
   i manage to do it with the edit and delete button (because they are found in the same component)
  but the add button is not there.
  how can i make the Vacations state be reloaded again in the child's component from his father component?</p>
  
  <pre><code>import React, { Component } from 'react';
  import apiUrl from './apiUrl';
  import AdminVacation from './AdminVacation';
  import AdminNavbar from './AdminNavbar'
  
  
  class AdminVacations extends Component {
      state={
          Vacations:[],
          userid:''
      }
  
  
      render() {
  
          return (
  
             &lt;div className="container"&gt;
  
  
          &lt;div class="row"&gt;
               {this.state.Vacations.map(data=&gt; &lt;AdminVacation key={data.id} data={data} RefreshFunc={this.RefreshFunc.bind(this)}  /&gt;)}
          &lt;/div&gt;
      &lt;/div&gt;
          )
      }
  
     async componentDidMount(){
  
      let response = await fetch(`${apiUrl}/allvacations`);
  
      let data = await response.json();
  
      this.setState({ Vacations:data })
  
      }
  
      RefreshFunc(){
          console.log("something Happened")
          this.componentDidMount() 
      }  
  }
  export default AdminVacations;
  </code></pre>
  
  <p>(basically i want to run componentDidMount in the Child's component (from Admin) again every time i add a Vacation - and not just when i edit it or delte it.
  the Edit and Delete are found in AdminVacation Component.</p>