Uncaught TypeError: Cannot read property 'state' of undefined

Question

I am trying to change from React.createClass to React.Component, but I am getting below error.

Uncaught TypeError: Cannot read property \'state\' of undefined 
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Answer 1

You need to bind this.onSelect If you forget to bind this.onSelect and pass it to onClick, this will be undefined when the function is actually called.

Try this:

class SectionAccordion extends React.Component {

      constructor(props){
        super(props);
        this.onSelect  = this.onSelect.bind(this);
      }

      onSelect() {

        this.props._onSelect(this.props.id);
      }

      render() {

            console.log("accordion / the Accordion Section component");
            var className = 'accordion-section' + (this.props._selected ? ' selected' : '');

            return (
                

                    

                        {this.props.title}
                    

                    




                    

                        {this.props.children}
                    
                
            );

      }

    }

Update:

You can bind the context using arrow function as well ; like this:

onSelect = () => {
   // code goes here
}