从 Javascript 更改 React Textarea 的值后触发事件

Question

I got a little Android App with a webview. I want to set a textareas value from there, which seems to be a react object.

It's working so far, I got the handle on the textarea and can set the value by my own javascript-routine. But the triggers are not called, so the form validation gives me an error the field would be empty.

I can manipulate the textarea with

document.getElementById('textareaId').value = "new value";

(I found the element by its properties and set the id myself for later use, so no need to tell react possibly isn't using ids)

How can I fire the events on the react objects?

I already tried to fire the events on the textarea itself but that doesn't seem to work. In the browser I see triggers onchange, onkeyup, onkeydown but I can't call them from outside, nor can I display them except from the browsers dev tools.

Any workaround for this would also be very welcome!

Answer 1

Seems to be just a matter of the right type of event:

var evt = document.createEvent("Events");            
evt.initEvent("change", true, true);                
textarea.dispatchEvent(evt);

from this answer simulate keyboard input / insert string into textarea (adwords)

did the trick.