4.8 KiB
jsPsych.pluginAPI
The pluginAPI module contains functions that are useful when developing new plugins.
jsPsych.pluginAPI.cancelAllKeyboardResponses
jsPsych.pluginAPI.cancelAllKeyboardResponses()
Parameters
None.
Return value
Returns nothing.
Description
Cancels all currently active keyboard listeners created by jsPsych.pluginAPI.getKeyboardResponse.
Examples
jsPsych.pluginAPI.cancelAllKeyboardResponses();
jsPsych.pluginAPI.cancelKeyboardResponse
jsPsych.pluginAPI.cancelKeyboardResponse(listener_id)
Parameters
| Parameter | Type | Description |
|---|---|---|
| listener_id | object | The listener_id object generated by the call to jsPsych.pluginAPI.getKeyboardResponse. |
Return value
Returns nothing.
Description
Cancels a specific keyboard listener created by jsPsych.pluginAPI.getKeyboardResponse.
Examples
// create a persistent keyboard listener
var listener_id = jsPsych.pluginAPI.getKeyboardResponse(after_response, ['p','q'], 'date', true);
// cancel keyboard listener
jsPsych.pluginAPI.cancelKeyboardResponse(listener_id);
jsPsych.pluginAPI.enforceArray
jsPsych.pluginAPI.enforceArray
Parameters
| Parameter | Type | Description |
|---|
Return value
Description
Examples
jsPsych.pluginAPI.getKeyboardResponse
jsPsych.pluginAPI.getKeyboardResponse(callback_function, valid_responses, rt_method, persist)
Parameters
| Parameter | Type | Description |
|---|---|---|
| callback_function | function | The function to execute whenever a valid keyboard response is generated. |
| valid_responses | array | An array of key codes or character strings representing valid responses. Responses not on the list will be ignored. An empty array indicates that all responses are acceptable. |
| rt_method | string | Indicates which method of recording time to use. The 'date' method uses calls to (new Date()).getTime() to record timing information. The 'performance' method uses calls to performance.now(), which is a more modern JavaScript feature. The 'performance' approach is not supported by all the major browsers yet, but adoption rates are increasing. |
| persist | boolean | If false, then the keyboard listener will only trigger the first time a valid key is pressed. If true, then it will trigger every time a valid key is pressed until it is explicitly cancelled by jsPsych.pluginAPI.cancelKeyboardResponse or jsPsych.pluginAPI.cancelAllKeyboardResponses. |
Return value
Return an object that uniquely identifies the keyboard listener. This object can be passed to jsPsych.pluginAPI.cancelKeyboardResponse to cancel the keyboard listener.
Description
Gets a keyboard response from the subject, recording the response time from when the function is first called until a valid response is generated.
A valid response triggers the callback_function specified in the parameters. A single argument is passed to the callback function. The argument contains an object with the properties key and rt. key contains the numeric key code of the response, and rt contains the response time.
Examples
Get a single response from any key
var after_response = function(info){
alert('You pressed key '+info.key+' after '+info.rt+'ms');
}
jsPsych.pluginAPI.getKeyboardResponse(after_response, [], 'date', false);
Get a responses from a key until the letter Q is pressed
var after_response = function(info){
alert('You pressed key '+info.key+' after '+info.rt+'ms');
if(info.key == 81){ // the key code for 'Q' is 81.
jsPsych.pluginAPI.cancelKeyboardResponse(listener);
}
}
var listener = jsPsych.pluginAPI.getKeyboardResponse(after_response, [], 'date', true);
jsPsych.pluginAPI.normalizeTrialVariables
jsPsych.pluginAPI.normalizeTrialVariables(trial, protect)
Parameters
| Parameter | Type | Description |
|---|---|---|
| trial | object | An object representing the trial (typically the same variable that gets passed to the plugin.trial method). It contains key: value pairs describing all the trial parameters. |
| protect | array | An array of strings, indicating which parameters in the trial object should be protected from normalization |
Return value
Returns a new trial object with all values that were functions replaced by the return value of the function.
Description
This method replaces any parameters that are functions with the output of the function.
Example
// a snippet from a trial method
plugin.trial = function(display_element, trial) {
trial = jsPsych.pluginAPI.normalizeTrialVariables(trial);
// the rest of the trial code...
}