I have a drop down built with extJS.
<input id="combo-1786-inputEl" data-ref="inputEl" type="text" size="1" name="Query Category" placeholder="Select query category" role="combobox" aria-hidden="false" aria-disabled="false" aria-readonly="false" aria-invalid="true" aria-required="true" aria-haspopup="true" aria-expanded="false" aria-autocomplete="list" class="x-form-field x-form-required-field x-form-text x-form-text-default x-form-invalid-field x-form-invalid-field-default x-form-empty-field x-form-empty-field-default" autocomplete="off" data-componentid="combo-1786" data-errorqtip="<ul class="x-list-plain"><li>This field is required</li></ul>" aria-describedby="combo-1786-ariaErrorEl">
As we can see the tag used is 'input' and not 'select'.
So when I looked up about how to populate it, most answers were made under the assumption that it was created using a 'select' tag and it did not work.
Also the drop downitems are fetched from DB only when I click on the arrow on the dropdown:

So as a result of this, the drop down items cant be found on the page source.
Can someone one please suggest how to populate such downs using the best practice?
P.S-I do have a workaround, but its not at all good code practice and not at all generic:
driver.findElement(By.xpath("//*[@id='combo-1731-trigger-picker']")).click();//clicking on the arrow key of the drop down.
//Once the drop down item comes, I am trying to replicate pressing the keyboard arrow key,by sending down arrow key to the drop down item(web element)
//This works for me because I know the extact position of my drop down item in the drop down item list.It will stop working if the postion of the drop item changes
//so below loop just presses the down arrow key required number of times.
for(int i=0;i<5;i++){
driver.findElement(By.xpath("//*[@id='combo-1731-inputEl']")).sendKeys(Keys.ARROW_DOWN);
}
driver.findElement(By.xpath("//*[@id='combo-1731-inputEl']")).sendKeys(Keys.ENTER);
If you read the comments mentioned along with the above code, then you can understand how fragile the logic is. Please help.