Placeholder function

example.js

// In your parent
import placeholderfunction from "./placeholderfunction";

class Parent extends Component {
    // A placeholder function is a function that is not yet implemented
    save = placeholderfunction();

    render() {
        <button onClick={this.save}>Save</button>
        <Child save={this.save} />
    }
}

// In your child controller
class ChildCtrl {
    constructor(props) {
        // Implement the Placeholder function with "this.save"
        props.save.implement(this.save);
    }

    save() {
        // do the work
    }
}

placeholderfunction.js

export default function createPlaceholderfunction() {
    var context = this;
    var implementation;
    var calls = [];
    const func = function placeholderfunction() {
        if(typeof implementation === "function") {
            implementation.apply(context,arguments);
        } else {
            calls.push(arguments);
        }
    };
    func.implement = (_implementation, _context) => {
        implementation = _implementation;
        if(_context) context = _context;
        calls.forEach(args => implementation.apply(context,args));
    };
    return func;
}