How to access custom attributes from event object in React?

Question

React is able to render custom attributes as described at http://facebook.github.io/react/docs/jsx-gotchas.html:

If you want to use a custom attribut

Answer 1

As of React v16.1.1 (2017), here is the official solution: https://reactjs.org/docs/handling-events.html#passing-arguments-to-event-handlers

TLDR: OP should do:

render: function() {
...
 this.removeTag(i, e)}>
...
removeTag: function(i, event) {
    this.setState({inputVal: i}); 
}