In React Semantic-UI, Input elements can be given a handy action button or icon as shown here:
http://react.semantic-ui.com/elements/input/#variations-action-icon-button
Unfortunately, the documentation is really poor at explaining how the action can trigger a function. The question of how you're meant to do this was asked here:
https://github.com/Semantic-Org/Semantic-UI-React/issues/1944
And the answer seems to be that you should use onClick on the icon or button. That would look something like this:
<Input
action={{
icon: 'play', onClick: (event,data)=>{console.log(data);}
}}
defaultValue="I bet you wish you could access this!"
/>
While that seems logical, it raises the question how do you access the value of the input, when the data passed to the onClick function describe the icon instead of the input?