Combobox != DropDownList
I am currently working on a fairly involved interface to administer data for a system that I built at work. In order to streamline the process, I am working on elements that allow users to select existing items for supporting data or create a new option inline. For some of the more involved elements, I am working out inline forms; for simpler items that can be captured as a single field of input, I wanted to use a combobox element. This is a web application and I am a big fan of jQuery, so I decided to look for a plugin that would give me the combobox functionality I was after.
What I found was a bit surprising. I found several pages of Google results that showed a fundamental lack of understanding around the term combobox.
Most of the information and plugins I found were basically replacements or enhancements for the HTML Select element. The select element gives you a dropdownlist of pre-set options to choose from. The plugins that I found were nice and offered some benefits over the standard select element, but they were not comboboxes.
The “combo” part of the name is short for combination. A combobox is the combination of a textbox and a dropdown. It should allow preset options while still allowing for a new value to be entered as plain text.
My guess is that if you are reading this, you knew this already, but maybe not. Maybe if, like me, you thought this was common knowledge, it will save you some of the surprise when you encounter it.