You can Do it through Jquery . Just change the type of your button from'Submit' to 'button'
and use the below code
$(document).ready(function(){
$('#YourButtonID').click(function(){
var EditorText=$('#YourEditorID').text();
if(EditorText!='')
{
//Perform Your Actions
}
else
{
// Write any user interactive validation message
alert('Kindly fill in some text in the editor');
}
})
})
Hope This Helps You