I have been trying to check the null fields in my application. I need to know the method which fires up as soon as i change the text in the textarea.
You can do something like this but it could be overkill:
Perhaps you can use https://www.npmjs.com/package/ember-cp-validations ??
Just use basic binding. Set the value of the box as a property, and use a computed property that depends upon that property.