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Creating a new Input type


To allow questions to be as flexible as possible, the types of input that can be used to build questions are a type of plugin. You can make a new one and add it to STACK if you wish. This document explains how.

File layout

Your new input type will be a folder inside question/type/stack/stack/input/. For the purpose of this example, we will suppose we are making an input type called myinput. So, the folder will be question/type/stack/stack/input/myinput.

Inside there, you should have two files:

  • myinput.class.php
  • tests/myinput_test.php - not strictly requried, but of course you want to write unit tests for your new code.


In this file, you need to define a subclass of stack_input called stack_myinput_input.

The methods you need to implement are well described by the PHPdoc comments on the base class, so go and read those now. The key methods are:

  • get_parameters_defaults - used by the question editing form.
  • render - displays the input element as HTML.


The best way to see how all this works is to have a look at how the inputs that come with stack as standard are implemented. It should be easy to learn by example.