Extensions¶

In jsPsych, extensions allow one to extend the functionality of various plugins, giving individual plugins the ability to collect more data, display additional stimuli, and more. A canonical example of an extension is eye tracking, which allow plugins to gather gaze data and add it to the their respective data objects. For a full list of extensions directly included in the jsPsych release, see here.

Using an Extension¶

To use an extension in an experiment, you'll load the extension file via a <script> tag (just like adding a plugin) and then initialize the extension in the parameters of initJsPsych().

<head>
  <script src="https://unpkg.com/jspsych@8.2.1"></script>
  <script src="https://unpkg.com/@jspsych/extension-example@1.0.0"></script>
</head>

initJsPsych({
  extensions: [
    { type: jsPsychExtensionExample, params: {...} }
  ]
})

To enable an extension during a trial, add the extension to the extensions list for the trial. Some extensions may also support or require an object of parameters to configure the extension:

var trial = {
  extensions: [
    { type: jsPsychExtensionExample, params: {...} }
  ]
}

Writing an Extension¶

See our developer's guide for extensions for information about how to create a new extension.