Here is how to use Selenium Webdriver with tinyMCE:
The tinyMCE editor creates its own iframe, so before selenium is able to perform any task or action on it, it has to first switch the control to the iframe and then start execution.
Here is how to switch this:
// Select the iframe driver.switchTo().frame("yourtxtarea_ifr"); // select the editor nad do the input driver.findElement(By.id("tinymce")).sendKeys("Dummy text");
Now after the WebDriver is all done with its actions on the editor it needs to switch back to the default window to continue with the rest of the script. Below is the sample code to switch back to the default window:
// switch back to the default window driver.switchTo().defaultContent();
Hope this helps. Please let us know in case of any issues.