send keys to ExtJS combobox, textbox, datefield, ...

SendKeys.java

//find the fully qualified component query of ExtJS component cmp
String query = cmp.componentQuery;
Component parent = cmp.parent;
 
while (parent != null) {
  query = parent.componentQuery + " " + query;
  parent = parent.parent;
}
//use component query to find id of inputEl
//the only change here is the addition of inputEl before .id
String js = "return Ext.ComponentQuery.query(\"" + query + "\")[0].inputEl.id;";
String id = (String) ((JavascriptExecutor) _driver).executeScript(js);
 
WebElement element = driver.findElement(By.id(id));

//Now, this web element accepts sendKeys
element.sendKeys("it works");