Call a React component method from outside

Question

I want to call a method exposed by a React component from the instance of a React Element.

For example, in this jsfiddle. I want to call the alertMessage

Answer 1

I use this helper method to render components and return an component instance. Methods can be called on that instance.

static async renderComponentAt(componentClass, props, parentElementId){
         let componentId = props.id;
        if(!componentId){
            throw Error('Component has no id property. Please include id:"...xyz..." to component properties.');
        }

        let parentElement = document.getElementById(parentElementId);

        return await new Promise((resolve, reject) => {
            props.ref = (component)=>{
                resolve(component);
            };
            let element = React.createElement(componentClass, props, null);
            ReactDOM.render(element, parentElement);
        });
    }